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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2021

For the transition period from to

Commission file number: 001-36182

Xencor, Inc.

(Exact Name of Registrant as Specified in its Charter)

(626) 305-5900

(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol Name of each exchange on which registered

Common Stock, par value $0.01 per share XNCR The Nasdaq Global Market

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes☒ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ☐No☒

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes⌧ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Securities Exchange Act of 1934). Yes ☐ No ☒

The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold as of June 30, 2021 was $2,000,288,972.

The number of outstanding shares of the registrant’s common stock, par value $0.01 per share, as of February 16, 2022 was 59,375,320.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A in connection with the registrant’s 2021 Annual Meeting of Stockholders, which will be filed subsequent to the date hereof, are incorporated by reference into Part III of this Form 10-K. Such proxy statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the registrant’s fiscal year ended December 31, 2021.

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Xencor, Inc.

FORM 10-K

For the Fiscal Year Ended December 31, 2021

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Page

PART I

Item 1 Business 4

Item 1A Risk Factors 28

Item 1B Unresolved Staff Comments 54

Item 2 Properties 55

Item 3 Legal Proceedings 55

Item 4 Mine Safety Disclosures 55

PART II

Item 6 [Reserved] 57

Item 7A Quantitative and Qualitative Disclosures About Market Risk 74

Item 8 Financial Statements and Supplementary Data 75

Item 9A Controls and Procedures 116

Item 9B Other Information 117

PART III

Item 10 Directors, Executive Officers and Corporate Governance 118

Item 11 Executive Compensation 118

Item 14 Principal Accounting Fees and Services 118

PART IV

Item 15 Exhibits, Financial Statement Schedules 118

Signatures 124

The Xencor logo is a trademark of Xencor, Inc. XmAb, PDA and Protein Design Automation are also registered trademarks of Xencor. All other product and company names are trademarks of their respective companies. References in this Annual Report on Form 10-K to “we”, “our”, “us”, “Xencor” or “the Company” refer to Xencor, Inc.

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PART I

Forward-Looking Statements

This Annual Report on Form 10-K contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. You should not place undue reliance on these statements. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends affecting the financial condition of our business. Forward-looking statements should not be read as a guarantee of future performance or results and will not necessarily be accurate indications of the times at, or by, which such performance or results will be achieved. Forward-looking statements are based on information available at the time those statements are made and/or management’s good faith belief as of that time with respect to future events, and are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in or suggested by the forward-looking statements. Our actual results could differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth below under Part I, Item 1A, “Risk Factors” in this Annual Report. These statements, which represent our current expectations or beliefs concerning various future events, may contain words such as “may,” “will,” “expect,” “anticipate,” “intend,” “plan,” “believe,” “estimate” or other words indicating future results. Such statements may include, but are not limited to, statements concerning the following:

● the success of our ongoing and planned clinical trials;

● our ability to protect our intellectual property position;

● the rate and degree of market acceptance and clinical utility of our products;

● significant competition in our industry;

● the potential loss or retirement of key members of management;

● our failure to maintain effective internal controls; and

Given these uncertainties, you should not place undue reliance on these forward-looking statements. These forward-looking statements represent our estimates and assumptions only as of the date of this Annual Report, and except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events, or otherwise after the date of this Annual Report. We qualify all of our forward-looking statements by these cautionary statements.

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Item 1. Business.

Our Business

We are a clinical-stage biopharmaceutical company focused on discovering and developing engineered monoclonal antibody and cytokine therapeutics to treat patients with cancer and autoimmune diseases who have unmet medical needs. We are advancing a broad portfolio of clinical-stage XmAb® drug candidates from our proprietary protein engineering technology platforms. We also use our protein engineering capabilities to increase our understanding of protein structure and interactions and to design new technologies and XmAb development candidates with improved properties. In addition to engineering protein-target interactions, our approach to protein design includes engineering Fc domains, the part of an antibody that interacts with multiple segments of the immune system and controls antibody structure. The Fc domain is constant and interchangeable among antibodies, and our engineered XmAb Fc domains can be readily substituted for natural Fc domains.

Our protein engineering capabilities and Fc technologies enable us and our partners to develop XmAb antibodies and biotherapeutic drug candidates with improved properties and functionality, which can provide innovative approaches to treating disease and potential clinical advantage over other treatment options. For example, we have developed an antibody scaffold to rapidly create novel bispecific antibodies that bind two different targets simultaneously, creating entirely new biological mechanisms. Other applications of our protein engineering technologies enhance antibody performance by increasing immune inhibitory activity, improving cytotoxicity, extending circulating half-life and stabilizing novel protein structures, such as engineered cytokines. Three marketed XmAb medicines have been developed with our protein engineering technologies and are generating royalties for us.

Our protein engineering capabilities allow us to continually explore new functionality in the Fc region, which provides us with opportunities to:

● Create new technology platforms;

Our Strategy

Our goal is to become a leading biopharmaceutical company focused on developing and commercializing engineered biologic medicines to treat patients with severe and life-threatening diseases with unmet medical needs. Key elements of our strategy are to:

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XmAb Bispecific Fc Domain and New Multi-Specific Antibody Formats

Our modular approach to protein engineering is a distinguishing feature of our Fc technologies. This inherent flexibility enables us to design new XmAb bispecific antibody and cytokine drug candidates with distinct and novel mechanisms-of-action and to seek out new applications of the XmAb Bispecific Fc Domain. Our business, research, and clinical efforts are to develop and advance our Fc technologies and our portfolio of XmAb bispecific antibody and engineered cytokine drug candidates in oncology and autoimmune diseases.

CD3 candidates: CD3 bispecific antibody candidates are designed to redirect T cells to tumor cells through the engagement of an antigen on tumor cells and CD3, an activating receptor on T cells. We are currently advancing two CD3 bispecific antibody candidates in Phase 2 clinical development: plamotamab and tidutamab.

We have significantly expanded the potential of our CD3 bispecific antibodies with the multi-specific XmAb 2+1 bispecific antibody format, utilizing two identical tumor targeting domains and one CD3 targeting domain. The affinities for antigen binding are engineered to enable selective engagement and killing of high antigen-expressing tumor cells over low antigen-expressing normal cells. In preclinical models, XmAb 2+1 bispecific antibodies bound preferentially to tumor cells compared to normal cells and effectively recruited T cells to kill tumor cells selectively. We

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believe that these properties will be particularly important when developing bispecific antibodies against many solid tumor targets, where standard monovalent targeting of tumor antigens could lead to poor tolerability because such targets are often expressed on a range of normal tissues, including critical organs. We are currently initiating a Phase 1 study for XmAb819, an ENPP3 x CD3 bispecific antibody, which is engineered with the XmAb 2+1 bispecific antibody format.

CD28 candidates: T cells in the tumor microenvironment require both T cell receptor (TCR) and co-stimulatory receptor engagement to achieve full activation. CD28 is a key immune co-stimulatory receptor on T cells; however, the ligands that activate T cells through CD28 are often not expressed on tumor cells. Targeted CD28 bispecific antibodies may provide conditional co-stimulation of T cells, for example, to T cells recognizing neoantigens or in concert with CD3 T-cell engaging bispecific antibodies. We have engineered XmAb bispecific antibodies to provide selective CD28 co-stimulation of T cells, activating them when bound to tumor cells, and we are conducting preclinical studies of internal CD28 candidates. Under our two collaborations with Janssen Biotech, Inc. (Janssen), we are applying our bispecific technologies to create and characterize CD28 bispecific antibody candidates against a prostate tumor target, and against multiple B cell targets.

TME activator candidates: Our tumor microenvironment (TME) activators have been designed to promote tumor-selective T-cell activation by targeting multiple checkpoints or co-stimulating receptors. These candidates also incorporate our XtendTM technology for longer half-life. We are currently advancing vudalimab in Phase 2 clinical development and are conducting Phase 1 studies for two additional TME activator candidates: XmAb841 and XmAb104.

Cytokine candidates: We have also expanded the use of our XmAb bispecific Fc domain to engineer novel cytokine candidates, which are not antibodies, but fusions of a heterodimeric Fc domain and immune signaling proteins. We engineer our cytokine candidates with reduced potency to improve therapeutic index and with our Xtend technology for longer half-life. Two XmAb cytokine candidates are being evaluated in Phase 1 studies: XmAb306 (RO7310729) and XmAb564.

We continue to invest in our protein engineering efforts to identify novel technologies and drug candidates.

Other XmAb Fc Domains

We have also created additional XmAb Fc domains, and we have successfully entered partnerships for these technologies and for XmAb drug candidates that incorporate them. We will continue to seek additional partnering and licensing opportunities for these Fc domains. Additional XmAb Fc domains include:

Approved or Authorized Medicines Engineered with XmAb Fc Domains

Currently three medicines that have been developed with our XmAb Fc domains are now marketed or made available by our partners. These medicines generated $80.3 million in royalty revenue for us in 2021, which has partially offset our internal development costs.

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Drug Candidates in Clinical Development

There are currently 21 clinical-stage drug candidates or marketed medicines that have been developed with one or more of our Fc technologies.

A partner is also advancing a drug candidate that incorporates our DN-TNF technology.

Vudalimab Plamotamab VIR-3434 Ultomiris*

Tidutamab XmAb306/RG6323 SARS-CoV-2 mAb Duo (BMS) Monjuvi*

XmAb104 Obexelimab Sotrovimab

XmAb564 Novartis bispecific antibody

AIMab7195

OMS906

*Alexion and MorphoSys are conducting additional Phase 3 studies in new indications with these candidates.

We regularly evaluate our portfolio of candidates and make additional investments in candidates with promising early-stage clinical data, partner out other candidates, and stop development of candidates where early clinical data does not support further investment. During 2021:

● We initiated Phase 2 studies for our vudalimab and tidutamab programs,

● We stopped development of the vibecotamab program.

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XmAb Bispecific Fc Drug Candidates in Clinical Development

Currently, 9 XmAb drug candidates that have been engineered with our XmAb bispecific Fc domain are in clinical development.

● Two candidates are being co-developed with partners; and

● Two additional candidates are being advanced by our partners.

Additional candidates are advancing through the preclinical stages of development. Drug candidates with our bispecific Fc domain, both bispecific antibodies and cytokines, in clinical development include:

The efficacy analysis included 78 evaluable patients receiving any amount of vudalimab, who had been followed for at least two cycles. Complete responses were observed in a patient with BRCA1+ high-grade serous ovarian cancer and in a patient with melanoma. Partial responses were observed in patients with melanoma (n=2), RCC (n=3), NSCLC (n=2) and CRPC (n=2). The objective response rate (ORR) across cohorts was 14.1% (11/78). All responses in patients with melanoma and CRPC and two responses in patients with RCC were confirmed. All responders, except those with CRPC, had received prior checkpoint inhibitor therapy. The median duration of response, unadjusted, for all responders was 18.3 weeks. The median duration of response, unadjusted, for patients with RCC was 24.1 weeks, and two patients remained on treatment.

Of the 12 efficacy-evaluable patients with CRPC, four had measurable disease and follow-up RECIST assessments, including the two CRPC responders. Six additional patients with CRPC, but without measurable disease, experienced a best overall response of non-CR/non-PD, as stable disease cannot be determined without measurable disease. The two CRPC responders had visceral and nodal metastases, had response durations of 41.3 and 27.0 weeks, were without progression on bone scans and had confirmed prostate-specific antigen (PSA) reductions of more than 50% from baseline. Among twelve patients with baseline and follow-up PSA assessments, including the two responders, 33% (4/12) had PSA reductions greater than 50%.

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We presented updated data from Part B and Part C of a Phase 1 dose-escalation study at the American Society of Hematology Annual Meeting in December 2021. Part B escalated dosing on administrations after the priming dose (doses between 80 and 360 mcg/kg). Part C established a step-up dosing regimen with higher, flat and less frequent dosing. The schedule, an intravenous, 50 mg flat dose every two weeks after step-up dosing during the first two cycles of treatment, was generally well tolerated and was determined to be the recommended Phase 2 dose.

The safety population included 50 patients in Part B (38 DLBCL, 12 FL) and 14 patients in Part C (8 DLBCL, 4 FL, 1 marginal zone lymphoma, 1 mantle cell lymphoma). Patients were heavily pretreated. The most common Grade 3 or 4 treatment-emergent adverse events (AEs) across all patients were anemia (21%), neutropenia (19%), hypophosphatemia (11%), thrombocytopenia (11%) and lymphopenia (10%). Four patients (5%) experienced Grade 3 or 4 cytokine release syndrome (CRS), each instance on the first dose, and no patients experienced Grade 3 or 4 CRS in Part C of the study. The rate of CRS of any grade fell from 74% in Part B to 57% in Part C. CRS was generally manageable with premedication. The efficacy analysis included 47 evaluable patients with either DLBCL or FL who were treated in Part B (n=38) or in Part C (n=9). The ORR was 51% (24/47), and complete responses were observed in 12 patients (26%). The median duration of response was 225 days for DLBCL and 171 days for FL, with six patients continuing to respond to plamotamab monotherapy.

In Part C, patients had generally more advanced disease and poorer responses to prior therapy. Of the 14 patients in Part C, eight patients received prior CAR-T and three patients received NK cell therapy; two of these patients received both. All eight patients with DLBCL received prior CAR-T therapy. In Part C, safety events were generally mild or moderate in severity. Grade 3 or 4 AEs experienced by more than 5% of patients included anemia (14%), lymphopenia (14%) and one patient each (7%) experiencing neutropenia, thrombocytopenia, decreases in neutrophil count, transaminase increases, fatigue and gamma-glutamyl transferase increases. The ORR was 100% (4/4) for FL, and CRs were observed in two patients (50%). For DLBCL, the ORR was 40% (2/5), and a CR was observed in one patient (20%). All 5 evaluable patients with DLBCL received prior CAR-T therapy, and two evaluable patients with DLBCL received prior NK cell therapy.

Expansion cohorts are actively recruiting patients with DLBCL and FL and are dosing using the recommended Phase 2 regimen to further evaluate the safety and efficacy of plamotamab monotherapy. We plan to present data from these cohorts in the second half of 2022.

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In November 2021, we announced preliminary data from the Phase 1 study, while further dose escalation in both study arms continues. At the time, the study had enrolled six cohorts in a monotherapy arm and four cohorts in an atezolizumab combination arm. XmAb306 was generally well tolerated as both a monotherapy and in combination with atezolizumab. No dose-limiting toxicities or treatment-related serious adverse events had been observed. Assessments of pharmacokinetics indicated that XmAb306 has a multi-day circulating half-life, which is consistent with its reduced-potency design and data generated in preclinical studies. Unconfirmed responses, as evaluated by RECIST criteria, had been observed in multiple tumor types, including in a patient treated with XmAb306 monotherapy. The study had recently reached dose levels that promote T cell activity, and evidence of peripheral effector T cell proliferation had been observed. Consistent and robust dose-dependent natural killer (NK) cell expansion and NK cell accumulation upon repeat dosing had been observed for multiple NK cell subsets, including mature NK cells. Significant NK cell expansion and accumulation was observed beginning in lower dose cohorts, and at higher dosing cohorts NK cell expansion had reached 40- to 100-fold higher levels than baseline and had been sustained for weeks throughout dosing.

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XmAb, Xtend, and Cytotoxic Fc Drug Candidates in Clinical Development

Currently, two drugs engineered with our Xtend Fc Domain and one drug we engineered with our XmAb Cytotoxic Fc Domain are marketed commercially by partners. In addition to these approved drugs, our partners are advancing six clinical-stage programs with antibodies engineered with XmAb, Xtend, and/or Cytotoxic Fc Domains, including:

Other Clinical Stage Drug Candidates

Collaborations, Partnerships and Licensing Arrangements

A key part of our business strategy is to leverage our protein engineering capabilities, XmAb technologies, and XmAb drug candidates with partnerships, collaborations, and licenses. Through these arrangements we generate revenues in the form of upfront payments, milestone payments, and royalties. For partnerships for our drug candidates, we aim to retain a major economic interest in these candidates through transactions that allow us to retain major geographic commercial rights, provide for profit-sharing on future sales of approved products, include co-development options, and also the right to conduct independent clinical studies with drug candidates developed in the collaboration.

Examples of arrangements we have entered with our partners include:

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Product Licenses

Product licenses are arrangements in which we license to third parties partial or full rights to develop and commercialize our internally developed drug candidates. We seek partners that can provide infrastructure and resources to successfully develop our drug candidates, have a track record of successfully developing and commercializing medicines, or have a portfolio of development-stage candidates and commercialized medicines which could potentially be developed in rational combinations with our drug candidates.

Janssen Biotech, Inc.

In October 2021, we entered into an agreement with Janssen Biotech, Inc. (Janssen) to develop, manufacture, and commercialize plamotamab and pursuant to which we, together, will conduct research and development activities to discover novel CD28 bispecific antibodies against undisclosed B cell tumor targets. Janssen will receive exclusive worldwide rights, subject to certain Xencor opt-in rights, to develop, manufacture and commercialize pharmaceutical products that contain one or more of such CD28 bispecific antibodies.

We received a $100.0 million upfront payment, and Johnson & Johnson Innovation, JJDC, Inc., purchased $25.0 million of newly issued unregistered shares of our common stock. In addition, we are eligible to receive milestone payments and royalties on net sales as follows:

We are collaborating with Janssen on further clinical development of plamotamab with Janssen paying 80% and the Company paying 20% of costs. We are conducting, at our own expense, a clinical collaboration to evaluate the combination of plamotamab, tafasitamab, and lenalidomide in patients with B-cell lymphoma after which Janssen may opt into cost sharing to further develop the combination after establishing proof of concept.

We are generally responsible for conducting research activities, and Janssen is generally responsible for all development, manufacturing, and commercialization activities for CD28 bispecific antibodies that are advanced. Independent of plamotamab development activities, upon clinical proof-of-concept for a CD28 bispecific antibody that is being developed outside of a plamotamab combination, we have the right to opt-in to fund 15% of development costs and, if we opt in to fund such development costs, to perform up to 30% of the detailing efforts in the United States. We would then be eligible for low-double digit to mid-teen percent royalties on net sales of those products.

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Genentech

In February 2019, we entered into an agreement with Genentech to develop and commercialize novel IL-15 cytokine therapeutics that use our bispecific Fc technology, including XmAb306, declared as a Collaboration Product under the agreement. We are jointly collaborating on the worldwide development of XmAb306 with Genentech maintaining worldwide commercialization rights, subject to us having a co-promotion option in the U.S. We retain the right to perform clinical studies with XmAb306 at our sole expense in combination with other therapeutic agents, subject to certain restrictions. Genentech received a worldwide exclusive license to XmAb306.

We received an upfront payment of $120.0 million. We are eligible to receive up to $160.0 million in clinical milestone payments for XmAb306, up to $180.0 million in clinical milestone payments for each new Collaboration Product, and a 45% share of net profits from sales from all Collaboration Products, while also sharing in the net losses at the same percentage rate. We are sharing in 45% of development and commercialization costs of Collaboration Products, while Genentech will pay for commercial launch costs.

MorphoSys AG

In July 2020, the FDA approved Monjuvi® (tafasitamab-cxix) in combination with lenalidomide for treating certain patients with DLBCL, and the European Commission granted conditional marketing authorization to tafasitamab for treating certain patients with DLBCL, which is marketed as Minjuvi® in Europe, in August 2021. In 2010, we licensed exclusive worldwide rights to develop and commercialize tafasitamab (formerly MOR208 and XmAb5574) to MorphoSys. Tafasitamab, which we engineered with an XmAb Cytotoxic Fc Domain, is the second XmAb medicine to be approved by the FDA.

In 2021, we earned $12.5 million in development milestones and royalties of $5.9 million on net sales. We are also eligible to receive up to $85.5 million in additional milestones for development of tafasitamab in additional oncology indications and $50.0 million in sales milestones across all indications. We are entitled to receive tiered royalties in the high-single digit to low-double digit percent range on net sales. Tafasitamab is co-marketed by Incyte and MorphoSys under the brand name Monjuvi® in the U.S., and is marketed by Incyte under the brand name Minjuvi® in the EU. Incyte has exclusive commercialization rights to tafasitamab outside the U.S.

Nestlé S.A./Aimmune Therapeutics, Inc.

In February 2020, we granted Aimmune Therapeutics, Inc., an exclusive worldwide license to develop and commercialize XmAb7195, which was renamed AIMab7195. We received an upfront payment of $9.6 million in cash and shares of Aimmune common stock. Aimmune was subsequently acquired by Nestlé S.A. Nestlé is responsible for all further development and commercialization activities for AIMAb7195. We are eligible to receive up to $385.0 million in milestones, which includes $22.0 million in development milestones, $53.0 million in regulatory milestones and $310.0 million in sales milestones, and tiered royalties in the high-single to mid-teen percent range on net sales of approved products. Nestlé is planning additional studies of AIMab7195.

INmune Bio, Inc.

In October 2017, we entered into an agreement with INmune Bio, Inc., in which we provided INmune with an exclusive license to our Xpro1595 drug candidate. In connection with the license, we received 1,585,000 shares of INmune common stock, an option to acquire up to 10% of the outstanding shares of INmune for $10.0 million, and an option to acquire 108,000 shares of common stock. In 2021, we sold the option to acquire up to 10% of INmune, and we received $15.0 million in cash proceeds and an additional 192,533 share of INmune common stock. We also exercised the option to acquire 108,000 shares of common stock for total proceeds of $0.8 million.

We are also eligible to receive a percentage of sublicensing revenue received for Xpro1595 and royalties in the mid-single digit percentage range on the sale of approved products. INmune is currently planning Phase 2 studies in Alzheimer’s disease, mild cognitive impairment, and treatment-resistant depression, as Xpro1595; Phase 2 studies in patients with non-alcoholic steatohepatitis, as LIVNate; and additional studies in MUC4-positive cancers, as INB03.

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Zenas BioPharma (Cayman) Limited

In November 2020, we entered into an agreement with Zenas BioPharma (Cayman) Limited (Zenas) to which we licensed the exclusive worldwide rights to develop and commercialize three preclinical-stage Fc-engineered drug candidates for autoimmune disease: XmAb6755, Xpro9523, and XmAb10171. These programs incorporate an Xtend Fc Domain, a Cytotoxic Fc Domain, or both. We received a 15% equity interest in Zenas, and we will also receive royalties on net sales of approved products in the mid-single digit to mid-teen percentage range.

In November 2021, we entered into a second agreement with Zenas to which we licensed the exclusive worldwide rights to develop and commercialize obexelimab, a bifunctional antibody that targets CD19 with its variable domain and uses our XmAb Immune Inhibitor Fc Domain. Zenas issued a warrant giving us the right to acquire additional Zenas equity, such that our total equity in Zenas would be 15% of its fully diluted capitalization following the closing of Zenas’ next round of equity financing, subject to certain requirements. We are also eligible to receive up to $470.0 million based on the achievement of certain clinical development, regulatory and commercialization milestones and are eligible to receive tiered, mid-single digit to mid-teen percent royalties upon commercialization of obexelimab, dependent on geography. Zenas will have sole responsibility for advancing the research, development, regulatory and commercial activities of obexelimab worldwide.

Novel Bispecific Antibody Collaborations

Novel bispecific antibody collaborations are arrangements in which our partner seeks to create an XmAb bispecific antibody using one or more of our bispecific technologies. Our partners provide an antibody or an antigen against tumors, and we conduct limited research and development activities to create potential bispecific antibody candidates for further development and commercialization by our partners.

Janssen Biotech, Inc.

In November 2020, we entered into an agreement, which became effective in December 2020, with Janssen Biotech, Inc. (Janssen), to develop XmAb bispecific antibodies against CD28 and an undisclosed prostate tumor target, for the potential treatment of patients with prostate cancer. Under the agreement, we conducted research activities to develop CD28 bispecific drug candidates for further development by Janssen. Preclinical activities and all clinical development, regulatory and commercial activities will be conducted by Janssen, which has exclusive worldwide rights to develop and commercialize the novel drug candidates developed in the collaboration. We received a $50.0 million upfront payment and are eligible to receive a total of $662.5 million in milestone payments which include $161.9 million in development milestones, $240.6 million in regulatory milestones, and $260.0 million in sales milestones. We are also eligible to receive tiered royalties in the high-single to low-double digit percentage range on net sales.

Upon development of a bispecific candidate by Janssen through proof of concept, the agreement provides us the right to opt-in to fund 20% of development costs and to perform up to 30% of detailing efforts in the U.S. If we exercise this right, we will be eligible to receive tiered royalties in the low-double digit to mid-teen digit percentage range.

Both we and Janssen also have the right to access predefined agents from each other’s portfolios to evaluate potential combination therapies in prostate cancer, subject to certain limitations.

In 2021, we received a $5.0 million milestone payment related to Janssen selecting a candidate for further development, and we are eligible to receive an additional $156.9 million in development milestones as the program advances.

Astellas Pharma, Inc.

In March 2019, we entered into an agreement with Astellas Pharma, Inc., under which we applied our XmAb bispecific Fc technology to an antigen pair provided by Astellas and generated bispecific antibody candidates for further certain characterization and testing. Astellas was granted a worldwide exclusive license, with the right to sublicense products in the field created by the research activities. Astellas has selected a bispecific antibody developed under the

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collaboration, ASP2138, a CLDN18.2 x CD3 bispecific antibody, for further development to treat patients with gastric, gastroesophageal, and pancreatic cancers. We received an upfront payment of $15.0 million, and we are eligible to receive up to $240.0 million in milestones which include $32.5 million in development milestones, $57.5 million in regulatory milestones and $150.0 million in sales milestones and royalties on net sales in the high-single to low-double digit percentage range. In 2020, we received a $2.5 million milestone payment related to Astellas advancing a bispecific candidate into IND enabling studies, and we are eligible to receive an additional $30.0 million in development milestones as the program advances.

Amgen Inc.

In September 2015, we entered into an agreement with Amgen Inc. to develop and commercialize bispecific antibody product candidates using our proprietary XmAb bispecific Fc technology.

Amgen applied our XmAb bispecific Fc technology to create AMG 509, a STEAP1 x CD3 XmAb 2+1 bispecific antibody. We have received a total of $60.5 million in upfront and milestone payments and are eligible to receive up to $255.0 million in future development, regulatory and sales milestone payments in total for AMG 509 and royalties on net sales.

Novartis AG

In connection with our June 2016 agreement with Novartis, we also applied our XmAb bispecific Fc technology to two target pair antibodies selected by Novartis. Novartis is responsible for development and commercialization of these programs. We are eligible to receive up to $250.0 million in milestone payments for each program which includes $50.0 million in development milestones, $100.0 million in regulatory milestones, and $100.0 million in sales milestones and royalties in the mid-single digit percent range on net sales of approved products. Novartis is conducting a Phase 1 study of an undisclosed bispecific antibody candidate and we received a $10.0 million milestone payment for this program in 2020.

Technology Licensing Agreements

We enter into technology licensing agreements in which we license access to one or more of our XmAb Fc technologies on a restricted basis, typically to our XmAb Cytotoxic Fc Domain and/or our Xtend Fc Domain. Our partners are responsible for all research, development and commercialization activities of the drug candidates. The plug-and-play nature of XmAb Fc domains allows us to license access to our platforms with no internal research and development activities required of us.

Alexion Pharmaceuticals, Inc.

Ultomiris® (ravulizumab-cwvz) was the first antibody incorporating XmAb Fc technology to be approved by the FDA for commercial marketing. It is approved in the U.S. and multiple global markets for the treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH) and for the treatment of patients with atypical hemolytic uremic syndrome (aHUS). Ultomiris is commercialized by Alexion Pharmaceuticals, Inc.

In 2013, we licensed Alexion the right to access our Xtend Fc domain, which Alexion used to develop an improved version of Alexion’s commercialized Soliris product. The Xtend technology increased the circulating half-life of Ultomiris by over three-fold compared to Soliris and extended the dosing schedule to bimonthly for Ultomiris compared to biweekly for Soliris. During 2021, we recorded royalty revenue of $22.2 million. We are eligible to receive an additional $20.0 million in sales milestones and a low-single digit percent royalty on the sale of approved products.

Vir Biotechnology, Inc.

Sotrovimab, an antibody that targets the SARS-CoV-2 virus, has received an emergency use authorization from the FDA and temporary authorizations in multiple global markets for the treatment of mild-to-moderate COVID-19 in high-risk adults and pediatric patients. In addition, Vir is evaluating VIR-7832 in a Phase 1b/2a trial of adults with mild-

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to-moderate COVID-19. In March 2020, we entered into an agreement in which we provided Vir a non-exclusive license to our Xtend technology to extend the half-life of novel antibodies, including sotrovimab, that Vir is investigating as potential treatments for patients with COVID-19. Vir is responsible for all research, development, regulatory and commercial activities for COVID-19 antibodies, and we are eligible to receive royalties on the net sales of approved products in the mid-single digit percentage range. During 2021, we recorded estimated royalty revenue of $52.2 million.

In August 2019, we entered into an agreement with Vir Biotechnology, Inc., in which we provided Vir a non-exclusive license to our Xtend technology for two targets in infectious disease. We have received a total of $1.5 million in upfront and milestone payments, and we are eligible to receive additional milestones of $154.5 million, including $4.5 million of development milestones, $30.0 million of regulatory milestones and $120.0 million of sales milestones. We are also eligible to receive royalties on the net sales in the low single digit percentage range. Vir has advanced two programs under this agreement. VIR-2482 is being evaluated in a Phase 1/2 study as a universal prophylactic for influenza A, and VIR-3434 is being evaluated in a Phase 2 combination study as a potential treatment for patients with hepatitis B virus infection.

Gilead Sciences, Inc.

In January 2020, we entered into an agreement with Gilead Sciences, Inc., in which we provided Gilead an exclusive license to our Cytotoxic Fc and Xtend Fc technologies for broadly neutralizing anti-HIV antibodies. Gilead is responsible for all development and commercialization activities. For each licensed antibody, we are eligible to receive up to $67.0 million in milestones, which includes $10.0 million in development milestones, $27.0 million in regulatory milestones, and $30.0 million in sales milestones. We are also eligible to receive royalties in the low-single digit percentage range on net sales of approved products.

Bristol-Myers Squibb Company

In May 2021, we entered into an agreement with Bristol-Myers Squibb Company (BMS), in which we provided BMS a non-exclusive license to our Xtend Fc technology to extend the half-life of antibodies that specifically bind to SARS-CoV-2. BMS is responsible for all research, development, regulatory and commercial activities. We are eligible to receive royalties on net sales of approved products in the low-single digit percentage range. BMS is evaluating the SARS-CoV-2 mAb Duo antibody combination therapy (BMS-986414 + BMS-986413) in the Phase 2/3 NIH ACTIV-2 trial in treating COVID-19 in outpatients.

Omeros Corporation

In August 2020, we entered into an agreement with Omeros Corporation, in which we provided Omeros a non-exclusive license to our Xtend Fc technology, an exclusive license to apply our Xtend Fc technology to an initial identified antibody, OMS906, and options to apply our Xtend Fc technology to three additional antibodies. Omeros is responsible for all development and commercialization activities. OMS906, a MASP-3 targeted antibody, is being evaluated in a Phase 1 study in patients with PNH and other alternative pathway disorders. We received an upfront payment of $5.0 million, and for each product incorporating our Xtend Fc technology, we are eligible to receive up to $65.0 million in milestones, which includes $15.0 million in development milestones, $25.0 million in regulatory milestones and $25.0 million in sales milestones. We are also eligible to receive royalties in the mid-single digit percentage range on net sales of approved products.

Viridian Therapeutics, Inc.

In December 2020, we entered into an agreement with Viridian Therapeutics, Inc., in which we provided Viridian a non-exclusive license to our Xtend Fc technology and an exclusive license to apply our Xtend Fc technology to antibodies targeting IGF-1R. Viridian is responsible for all development and commercialization activities. We received an upfront payment of 322,407 shares of Viridian common stock valued at $6.0 million and are eligible to receive up to $55.0 million in milestones, which include $10.0 million in development milestones, $20.0 million in regulatory milestones and $25.0 million in sales milestones. We are also eligible to receive royalties in the mid-single digit percentage range on net sales of approved products.

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In December 2021, we entered into a second agreement with Viridian for a non-exclusive license to certain antibody libraries developed by us. Under the agreement, Viridian received a one-year research license to review the antibodies and the right to select up to three antibodies for further development. Viridian is responsible for all further development of the selected antibodies. We received an upfront payment of 394,737 shares of Viridian common stock valued at $7.5 million and are eligible to receive development, regulatory and sales milestones in addition to royalties on net sales of approved products under the agreement.

Astria Therapeutics, Inc/Catabasis Pharmaceuticals, Inc./Quellis Biosciences, Inc.

In May 2018, we entered into an agreement with Quellis Biosciences, Inc., in which we provided Quellis a non-exclusive license to our Xtend Fc technology to apply to an identified antibody. Quellis is responsible for all development and commercialization activities. We received an equity interest in Quellis, and in January 2021, upon Quellis merging into Catabasis Pharmaceuticals, Inc., we received common and preferred shares of Catabasis stock in exchange for our equity in Quellis. Catabasis subsequently changed its name to Astria Therapeutics, Inc. We are eligible to receive up to $66.0 million in milestones, which include $6.0 million in development milestones, $30.0 million in regulatory milestones and $30.0 million in sales milestones. We are also eligible to receive royalties in the mid-single digit percentage range on net sales of approved products.

Strategic Collaborations

We enter into strategic collaborations where we can create synergies between our partners’ capabilities and assets and our own protein engineering capabilities, Fc technologies and XmAb drug candidates. Through these arrangements we seek to create new drug candidates, investigate novel combination therapies and potentially identify additional indications for our portfolio of XmAb drug candidates.

MorphoSys AG

In November 2020, we entered into a strategic collaboration with MorphoSys AG and Incyte to conduct clinical studies to investigate the chemo-therapy free combination of plamotamab and tafasitamab in combination with lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), first-line DLBCL, and relapsed or refractory follicular lymphoma (FL). MorphoSys and Incyte Corporation will provide tafasitamab for the studies, which Xencor will sponsor and fund.

Atreca, Inc.

In July 2020, we entered into an agreement with Atreca, Inc., to research, develop and commercialize novel CD3 bispecific antibodies as potential therapeutics in oncology. During a three-year research term, Atreca will provide antibodies against novel tumor targets through its discovery platform from which we will engineer XmAb bispecific antibodies that bind to the CD3 receptor on T cells. The two companies will share research costs equally during the research term. Up to two joint programs are eligible to be mutually selected for further development and commercialization, with each partner sharing 50% of costs and profits. Each company has the option to lead development, regulatory and commercialization activities for one of the joint programs. In addition, each partner has the option to pursue up to two programs independently, with a royalty in the mid- to high-single digit percentage range payable on net sales to the other partner.

The University of Texas MD Anderson Cancer Center

In September 2020, we entered into an agreement with MD Anderson, in which we will provide funding over a five-year period, and MD Anderson will collaborate to design and execute additional clinical studies with our portfolio of XmAb drug candidates, including novel bispecific antibody and cytokine candidates. We own all rights to the programs and results generated from these studies. In December 2021, we extended the agreement for an additional year at the same level of committed funding.

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In December 2020, we entered into a second agreement with MD Anderson to develop novel CD3 bispecific antibody therapeutics for the potential treatment of patients with cancer. MD Anderson will work to identify and develop potential antibodies, and we will apply its our Fc bispecific technology to create therapeutic candidates. MD Anderson will then conduct and fund all preclinical activities to advance candidates toward clinical studies. We have certain exclusive options to license worldwide rights to develop and commercialize potential new medicines arising from the collaboration.

Our Research and Development Pipeline

We have used our XmAb Fc platforms and protein engineering capabilities to produce a growing pipeline of drug candidates in clinical and preclinical development. These include multiple oncology candidates using our bispecific Fc domain, including bispecific antibody and cytokine candidates. We continue to advance these candidates as additional options for clinical development by us or as out-licensing opportunities. We also from time to time in-license antibody technologies and compounds from other companies which we believe may allow us to create potential product candidates by incorporating our own proprietary technologies. These licenses may require us to pay upfront fees, development, and commercial milestone payments, and if commercial products are approved, royalties on net sales.

Human Capital Management

Our Employees and Commitment to Diversity, Equity, and Inclusion

Our ability to develop XmAb technologies, advance our programs into late-stage development, position our programs for commercialization and identify successful business partnerships is dependent on attracting, retaining, and developing our employees. We seek and support a diverse population of employees without regard to race, gender or sexual orientation. As of December 31, 2021, we had 254 full-time employees, representing a 26% increase in our employee workforce as compared to December 31, 2020. Of these, 205 were engaged in research and development activities, and 49 were engaged in business development, information systems, facilities, human resources, or administrative support. Of these employees, 65 hold Ph.D. degrees, and 10 hold M.D. degrees. None of our employees are represented by any collective bargaining unit. We believe we maintain good relations with our employees.

We are an equal opportunity employer and maintain policies that prohibit unlawful discrimination based on race, color, religion, gender, sexual orientation, gender identity/expression, national origin/ancestry, age, disability, marital and veteran status. We are proud to employ a diverse workforce that, as of December 31, 2021, was 57% non-white and 56% women. In addition, as of December 31, 2021, women made up 22% of our senior leadership team. We strive to build and nurture a culture where all employees feel empowered to be their authentic selves.

We seek to provide human capital and employee health and safety policies that provide for the health, safety, and welfare of our employees. We continue practices that address the COVID-19 pandemic consistent with government guidelines to mitigate and prevent the spread of disease, such as masking, social distancing, contact tracing, and encouraging vaccinations. In 2021, in connection with the ongoing pandemic we continued the following practices:

Compensation, Benefits, and Development

We provide compensation packages designed to attract, retain, and motivate high-quality employees, and all of our employees are eligible for cash bonuses and grants of equity awards. We regularly evaluate our compensation programs with an independent compensation consultant and utilize industry benchmarking in an effort to ensure they are

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competitive compared to similar biotechnology and biopharmaceutical companies with which we compete for talent and that they are fair and equitable across our workforce with respect to gender, race, and other personal characteristics. All employees are eligible to participate in the Employee Stock Purchase Plan where they can purchase shares of Xencor common stock at a discounted price. This plan, and our other equity compensation plans, assists us in building long-term relationships with our employees and aligns the interest of employees with stockholders. We also deliver a benefits program that is designed to keep our employees and their families healthy, which includes not only medical, dental and vision benefits, but also dependent care, mental health, and other wellness benefits. In addition, we provide a variety of programs and services to help employees meet and balance their needs at work, at home and in life.

We value career development for all employees, and we provide reimbursement and time for employees to attend professional development courses ranging from technical training, competency-based workshops, and leadership development programs. Direct managers also take an active role in identifying individualized development plans to assist their employees in realizing their full potential and creating opportunities for promotions and added responsibilities that enhance the engagement and retention of our workforce.

Market Opportunity

Our drug candidates that use the XmAb bispecific Fc domain, including plamotamab, vudalimab, tidutamab, XmAb841, XmAb104, XmAb306, and XmAb564: We are developing our bispecific antibody and cytokine candidates to treat cancer. Cancer is a broad group of diseases in which cells divide and grow in an uncontrolled fashion, forming malignancies that can invade other parts of the body, and it is the second leading cause of death in the United States (U.S.). The American Cancer Society estimates that in 2022 there will be approximately 1.9 million new cases of cancer and approximately 609,360 deaths from cancer. The National Institutes of Health (NIH) estimated that based on growth and aging of the U.S. population, medical expenditures for cancer in the year 2030 are projected to reach at least $245.6 billion.

Intellectual Property

The foundation for our XmAb technology and our product candidates and partnering is the generation and protection of intellectual property for novel antibody and cytokine therapeutics. We combine proprietary computational methods for amino acid sequence design with laboratory generation and testing of new antibody and cytokine compositions. Our design and engineering team prospectively assesses, with patent counsel, the competitive landscape with the goal of building broad patent positions and avoiding third-party intellectual property.

As a pioneer in Fc domain engineering, we systematically scanned the structure of the Fc domain to discover Fc variants. We have filed patent applications relating to thousands of specific Fc domain variants with experimental data on specific improvements of immune function, pharmacokinetics, structural stability, and novel structural constructs. We have filed additional patent applications derived from these applications as we discover new properties of the Fc variants and as new business opportunities arise. We continually seek to expand the intellectual property coverage of our technology and candidates and invest in discovering new Fc domain technologies, antibody product candidates, and cytokine product candidates.

Our patent estate, on a worldwide basis, includes over 1,300 issued patents and pending patent applications which we own, with claims directed to XmAb Fc domains, all of our clinical and preclinical stage product candidates and our computational protein design methods and platforms. We also have a large number of issued patents and pending patent applications with claims directed specifically to our XmAb technology and candidates.

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The patent expiration in the U.S. and major foreign countries (ex-U.S.) for our key technologies and drug candidates is set forth below. We have pending applications filed that may extend the exclusivity of some of our technology and products:

Technology Patent Expiry

Bispecific 2034 U.S. and Ex-U.S.

CD3 T Cell Engagers 2035 U.S. and Ex-U.S.

CD28 T Cell Engagers 2040 U.S. and Ex-U.S.

Company Products Patent Expiry

Tidutamab 2037 U.S. and Ex-U.S.

Vudalimab, XmAb841, XmAb104 2037 U.S. and Ex-U.S.

Partnered Products Patent Expiry

Monjuvi (tafasitamab) 2029 U.S.; 2027 Ex-U.S.

Plamotamab 2035 U.S. and Ex-U.S.

The Hatch-Waxman Act permits a patent term extension for FDA-approved drugs, including biological products, of up to five years beyond the expiration of the patent. The length of the patent term extension is related to the length of time the drug is under regulatory review. Patent extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be extended. Similar provisions are available in Europe and other jurisdictions to extend the term of a patent that covers an approved drug. In the future, if and when our pharmaceutical product candidates receive FDA approval, we expect to apply for patent term extensions on patents covering those products. We intend to seek patent term extensions to any of our issued patents in any jurisdiction where these are available; however, there is no guarantee that the applicable authorities, including the FDA in the United States, will agree with our assessment of whether such extensions should be granted, and even if granted, the length of such extensions.

The Patient Protection and Affordable Care Act, as amended by the Healthcare and Education Affordability Reconciliation Act (collectively the ACA) created a regulatory scheme authorizing the FDA to approve biosimilars via an abbreviated licensure pathway. In many cases, this allows biosimilars to be brought to market without conducting the full suite of clinical trials typically required of originators. Under the ACA, a manufacturer may submit an application for licensure of a biologic product that is "biosimilar to" or "interchangeable with" a previously approved biological product or "reference product." The "biosimilar" application must include specific information demonstrating bio similarity based on data derived from: (1) analytical studies, (2) animal studies, and (3) a clinical study or studies that are sufficient to demonstrate safety, purity, and potency in one or more appropriate conditions of use for which the reference product is licensed, except that FDA may waive some of these requirements for a given application. Under this new statutory scheme, an application for a biosimilar product may not be submitted to the FDA until four years after the date of first licensure. The FDA may not approve a biosimilar product until 12 years from the date on which the reference product was first licensed. The law does not change the duration of patents granted on biological products. Even if a product is considered to be a reference product eligible for exclusivity, another company could market a competing version of that product if the FDA approves a full Biologics License Application (BLA) for such product containing the sponsor's own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity, and potency of their product. There have been recent proposals to repeal or modify the ACA, and it is uncertain how any of those proposals, if approved, would affect these provisions.

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In addition to patent protection, we rely on trade secret protection and know-how to expand our proprietary position around our technology and other discoveries and inventions that we consider important to our business. We seek to protect this intellectual property in part by entering into confidentiality agreements with our employees, consultants, scientific advisors, clinical investigators, and other contractors and also by requiring our employees, commercial contractors, and certain consultants and investigators, to enter into invention assignment agreements that grant us ownership of certain discoveries or inventions made by them.

Further, we seek trademark protection in the United States and in certain other jurisdictions where available and when we deem appropriate. We have obtained registrations for the Xencor trademark, as well as certain other trademarks, which we use in connection with our pharmaceutical research and development services and our clinical-stage products, including XmAb. We currently have registrations for Xencor and PDA in the United States, Australia, Canada, the European Community, and Japan, for Protein Design Automation in the United States, Australia, Canada, and the European Community, and for XmAb in the United States, Australia, Canada, the European Community and Japan.

Third Party Vendors and Suppliers

Our internal research activities are focused on early research stage and preclinical activities and studies. We rely on third party vendors, suppliers and contractors for all other research, development and clinical activities. We are able to internally manufacture the quantities of our product candidates required for relatively short preclinical animal studies. We believe that this allows us to accelerate the drug development process by not relying on third parties for all of our manufacturing needs. We have adopted a manufacturing strategy of contracting with third parties in accordance with current good manufacturing practices (cGMPs) for the manufacture of drug substance and product, including our pipeline of bispecific antibody and cytokine development candidates. We have used third party manufacturers for all our bispecific antibody and cytokine candidates which include: plamotamab, tidutamab, vudalimab, XmAb841, XmAb104, XmAb306, XmAb564, and XmAb819. Additional contract manufacturers are used to fill, label, package and distribute investigational drug products. This allows us to maintain a more flexible infrastructure while focusing our expertise on developing our products. We do not have any long-term manufacturing agreements in place and will ultimately depend on contract manufacturers for the manufacture of our products for commercial sale, as well as for process development.

KBI Biopharma, Inc.

In July 2014, we entered into a master services agreement (KBI Agreement) with KBI Biopharma, Inc. (KBI). We have engaged KBI under the KBI Agreement for process development, clinical scale-up, analytical method development, formulation development, and other services related to drug substance and drug product for our bispecific antibody and cytokine development candidates: plamotamab, tidutamab, vudalimab, XmAb841, XmAb104, XmAb306, and XmAb564 in accordance with cGMP regulations. For each bispecific program, we have entered into a separate agreement with the terms and conditions of services and payment. The KBI Agreement is for a three-year term but is automatically extended on an annual basis until the services are completed. The KBI Agreement may be terminated by either party for a breach that is not remedied within 30 days after notice or 60 days after notice of the existence of an incurable scientific or technical issue that renders KBI unable to render services under the KBI Agreement, by after 60-day notice, or in the event of a bankruptcy of a party. For termination other than a material breach by KBI, we must pay for all services conducted prior to the termination and to wind down the activities.

Cell Line Agreements with Selexis

In December 2015, we entered into a master service agreement (Selexis Agreement) with Selexis SA (Selexis) for the manufacture of Selexis cell lines. Under the terms of the Selexis Agreement, Selexis will manufacture cell lines for the antibody candidates provided by us and upon completion of the cell lines, we have the option to take an unrestricted commercial license to the cell line. The terms of each commercial license require us to make payments upon achievement of certain development and regulatory milestones and we will also pay royalties based on a percentage of net sales for products that are derived from or utilize the Selexis cell line. The royalty is less than 1%.

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Selexis has manufactured cell lines for certain of our bispecific antibody and cytokine drug candidates, and we currently have rights to obtain commercial licenses to the Selexis cell line for the following bispecific antibody and cytokine candidates: plamotamab, tidutamab, vudalimab, XmAb841, XmAb104, XmAb306, XmAb564, and XmAb819.

License Agreements with BIO-TECHNE

In February 2015, we entered into a license agreement with BIO-TECHNE Corporation (BIO-TECHNE) for a non-exclusive license to certain antibody technology including monoclonal antibodies which recognize human somatostatin receptor 2 (SSTR2). The variable domain of this antibody is incorporated in our tidutamab drug candidate. Under the terms of this agreement, we made an upfront payment and are obligated to make payments upon the achievement of certain development and regulatory milestones, and royalties based on a percentage of net sales from products that are derived from the tidutamab program. The royalty is less than 1%.

We entered into a second agreement with BIO-TECHNE effective February 2018 for a non-exclusive license to a certain recombinant monoclonal antibody reactive with human programmed death protein, PD-1. We expect to use this protein in certain of our oncology drug candidates. Under the terms of this agreement, we made an upfront payment and are obligated to make payments upon the achievement of certain development, regulatory and sales milestones, and royalties based on a percentage of net sales from products that are derived from the PD-1 antibody. The royalty is 1%.

Umbrella Development Services Agreement with Patheon Biologics LLC

In September 2018, we entered into an Umbrella Development Services Agreement (Patheon Agreement) with Patheon Biologics LLC (Patheon). Under the terms of the Patheon Agreement, any of the affiliates within the global network of service sites in Thermo Fisher Scientific Inc.’s Pharma Services Group may perform clinical manufacturing and development services for us in accordance with cGMP regulations. The Patheon Agreement may be terminated by either party for a breach or default that is not remedied within 30 days, or such other time period as may be reasonably necessary to remedy such breach after receiving notice of the breach from the non-breaching party or if the other party is subject to an insolvency event. We have the unilateral right to terminate the Patheon Agreement upon 30 days written notice to Patheon for any business reason, subject to cancellation fees. Patheon has the unilateral right to terminate the Patheon Agreement if we request to reschedule work beyond 120 days, the project work is not progressing according to our expectations and we cannot agree on appropriate changes, after six months of inactivity on a project at our request or if Patheon determines it is unable to perform its obligations in a safe and effective way in compliance with applicable regulatory requirements.

Patheon is currently conducting process transfer, process development and cGMP manufacturing for our XmAb819 program.

Master Services Agreement with WuXi Biologics (Hong Kong) Limited

In February 2021, we entered into a Master Services Agreement (WuXi Agreement) with WuXi Biologics (Hong Kong) Limited (WuXi). Under the terms of the WuXi Agreement, WuXi and its affiliates will perform manufacturing, analytical, development and other services for Xencor in accordance with applicable regulations. The WuXi Agreement includes customary rights to replacement of non-conforming products. The WuXi Agreement may be terminated by either party for a breach by the other party that is not remedied within 45 days (or 10 days for a non-payment breach), or if the other party is subject to an insolvency event. We have the unilateral right to terminate the WuXi Agreement upon 90 days’ prior written notice to WuXi for any reason, subject to applicable cancellation fees. WuXi has the unilateral right to terminate the WuXi Agreement only if the services cannot be performed due to technical difficulties or the performance of the services is not permitted under applicable law.

WuXi is currently conducting process transfer, process development and cGMP manufacturing for our XmAb808 (B7-H3 x CD28) and our IL-12 programs.

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Master Clinical Services Agreement with ICON Clinical Research Limited

In April 2016, we entered into a Master Clinical Services Agreement (ICON Agreement) with ICON Clinical Research Limited (ICON). Under the terms of the ICON Agreement, ICON and its affiliates will perform clinical trial services (including site selection, study design, site monitoring, management and training, and patient selection) for Xencor in accordance with applicable regulations. The ICON Agreement may be terminated by either party for a breach by the other party that is not remedied within 30 days, or if the other party is subject to an insolvency event. Each party may terminate the ICON Agreement upon 30 days’ prior written notice to the other party for any reason, however such termination would not affect any ongoing project under the ICON Agreement. We may unilaterally terminate any project under the ICON Agreement upon 30 days’ prior written notice to ICON for any reason, subject to applicable termination fees.

ICON is currently providing services to us in connection with each ongoing Xencor-sponsored clinical trial.

Competition

We compete in an industry that is characterized by rapidly advancing technologies, intense competition, and a strong emphasis on proprietary products. Our competitors include pharmaceutical companies, biotechnology companies, academic institutions, and other research organizations. We compete with these parties for promising targets for antibody-based therapeutics, new technology for optimizing antibodies and cytokines, and in recruiting highly qualified personnel. Many competitors and potential competitors have substantially greater scientific, research, and product development capabilities as well as greater financial, marketing and sales, and human resources than we do. In addition, many specialized biotechnology firms have formed collaborations with large, established companies to support the research, development, and commercialization of products that may be competitive with ours. Accordingly, our competitors may be more successful than we may be in developing, commercializing, and achieving widespread market acceptance. In addition, our competitors’ products may be more effective, more effectively developed, or more effectively marketed and sold than any treatment we or our development partners may commercialize, which may render our product candidates obsolete or noncompetitive before we can recover the expenses related to developing and commercializing any of our product candidates.

Competition in the field of cancer drug development is intense, with hundreds of compounds in clinical trials. Many large pharmaceutical companies and other smaller biotechnology companies are developing competing bispecific antibody platforms, and many of these companies have advanced multiple drug candidates into clinical development, including Amgen Inc.; Genmab A/S; Macrogenics, Inc.; Merus N.V.; Regeneron Pharmaceuticals, Inc.; and Roche Holding AG.

We are developing bispecific antibody drug candidates engineered to direct cytotoxic T cell killing of tumor cells, by engaging the CD3 receptor on T cells and an antigen on tumor cells. Regarding plamotamab, other companies developing CD3 bispecific antibodies directed to CD20, an antigen expressed on many blood tumors, include AbbVie Inc. and Genmab A/S; IGM Biosciences, Inc.; Regeneron Pharmaceuticals, Inc.; and Roche Holding AG. Other antibodies, antibody drug candidates and cell therapies are in development or approved to treat patients with non-Hodgkin lymphomas.

We are also developing several bispecific antibody drug candidates engineered to selectively engage the immune system in order to treat patients with cancer, such as vudalimab, XmAb841 and XmAb104. Immuno-oncology is a competitive field within the biotechnology and pharmaceutical industries, and most large pharmaceutical companies are developing drug candidates, have marketed medicines in this space, or both: AstraZeneca plc; Bristol-Myers Squibb Company; GlaxoSmithKline plc; Merck & Co., Inc.; Novartis AG; Pfizer Inc.; Roche Holding AG; and Sanofi S.A. While tuning the binding affinities plays a crucial role in designing the mechanism of action for this class of bispecific antibody, smaller companies advancing clinical programs that, like vudalimab, dually target the immune checkpoint receptors PD-1 and CTLA-4 include Akeso, Inc. and Macrogenics, Inc.

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Several companies are developing engineered cytokines intended to activate specific immune cell populations in order to treat patients with cancer and/or autoimmune diseases, including Alkermes plc; Amgen Inc.; Cue Biopharma, Inc.; Cytune Pharma; Eli Lilly and Company; IGM Biosciences, Inc.; ImmunityBio, Inc.; Kadmon Holdings, Inc.; Medicenna Therapeutics Corp.; Merck & Co., Inc.; Nektar Therapeutics, Inc.; Neoleukin Therapeutics, Inc.; Novartis AG; Roche Holding AG; Sanofi S.A.; Sutro Biopharma, Inc.; and Xilio Therapeutics, Inc.

In addition, we are aware of a number of other companies with development-stage programs that may compete with the drug candidates we and our licensees are developing in the future. We anticipate that we will face intense and increasing competition as new treatments enter the market and advanced technologies become available.

Regulatory Overview

Our business and operations are subject to a variety of U.S. federal, state and local and foreign supranational, national, provincial, and municipal laws, regulations and trade practices. The FDA and comparable regulatory authorities in state and local jurisdictions and in other countries impose substantial and burdensome requirements upon companies involved in the clinical development, manufacture, marketing, and distribution of drugs and biologics. These agencies and other federal, state and local entities regulate research and development activities and the testing, manufacture, quality control, safety, effectiveness, labeling, storage, recordkeeping, approval, advertising and promotion, and export and import of our product candidates.

U.S. Government Regulation

We are subject to extensive regulation by the U.S. and other countries. Regulation by government authorities is a significant factor in development, manufacture, distribution and ongoing research activities. All our products in development will require regulatory approval by government agencies prior to commercialization. In particular, drugs and biologic products are subject to rigorous preclinical studies and clinical trials and other approval procedures of the FDA and similar regulatory authorities in foreign countries. The process of obtaining these approvals and the subsequent compliance with appropriate federal and state statutes and regulations require the expenditure of substantial time and financial resources. Various federal and state statutes and regulation also govern or influence testing, manufacturing, safety, labeling, storage, tracking, tracing and record-keeping of drugs and biologic products and their marketing.

U.S. Drug Development Process

In the United States, the FDA regulates drugs and biologic products under the Federal Food, Drug and Cosmetic Act (FDCA), its implementing regulations, and other laws including, in the case of biologics, the Public Health Service Act. Our product candidates are subject to regulation by the FDA as a biologic. Biologics require the submission of a Biologics License Application (BLA) to the FDA and approval of the BLA by the FDA before marketing in the United States. The process of obtaining regulatory approvals for commercial sale and distribution and the subsequent compliance with applicable federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources. Failure to comply with the applicable requirements at any time during the product development process, approval process or after approval, may subject an applicant to administrative or judicial civil or criminal sanctions. These sanctions could include the FDA’s refusal to approve pending applications, license suspension or revocation, withdrawal of an approval, imposition of a clinical hold on clinical trials, warning letters, product recalls, product seizures, total or partial suspension of production, or distribution, injunctions, fines, refusals of government contracts, restitution, disgorgement or civil and/or criminal penalties. The process required by the FDA before a biologic may be marketed in the United States generally involves the following:

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4. submission to and acceptance by the FDA of a BLA;

8. FDA review and approval of the BLA prior to any commercial marketing or sale.

Before testing any compounds with potential therapeutic value in humans, the product candidate enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry, stability, and formulation, as well as animal studies to assess the potential toxicity and activity of the product candidate. Clinical trials involve the administration of the product candidate to human patients under the supervision of qualified investigators, generally physicians not employed by or under the clinical trial sponsor’s control. Clinical trials are conducted under protocols detailing, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria, and the parameters to be used to monitor subject safety and effectiveness. The FDA or responsible Institutional Review Board may place a trial on hold at any time related to perceived risks to patient safety. Phases of clinical development include:

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the biologic and finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements.

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U.S. Review and Approval Processes

The results of product development, preclinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests, proposed labeling, and other relevant information are submitted to the FDA in the form of a BLA requesting approval to market the product for one or more specified indications. The standard time for the FDA to accept a BLA submission is two months.

If the FDA determines that the BLA is substantially complete, it will accept the BLA for review.

Once accepted, the FDA reviews the BLA to determine, among other things, whether the proposed product is safe and effective for its intended use, and whether the product is being manufactured in accordance with cGMP to assure and preserve the product’s identity, strength, quality, and purity, and it may inspect the manufacturing facilities to assure cGMP compliance and clinical sites used during the clinical trials to assure cGMP compliance. The standard FDA review process is 10 months once a BLA is accepted for review, but it can take longer. During the review process, the FDA also will determine whether a risk evaluation and mitigation strategy (REMS) is necessary to assure the safe use of the product. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS prior to approval. A REMS can substantially increase the costs of obtaining approval. In addition, under the Pediatric Research Equity Act, a BLA or supplement to a BLA must contain data that are adequate to assess the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations, and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may, on its own initiative or at the request of the applicant, grant deferrals for submission of some or all pediatric data until after approval of the product for use in adults, or full or partial waivers from the pediatric data requirements.

The FDA will issue a complete response letter describing deficiencies in the BLA and recommend actions if the agency decides not to approve the BLA. The applicant will have to address all of the deficiencies which could take substantial time to address.

If the product receives regulatory approval, the approval may be significantly limited to specific diseases and dosages, or the indications for use may otherwise be limited and may require that certain contraindications, warnings, or precautions be included in the product labeling. In addition, the FDA may require post marketing studies, sometimes referred to as Phase 4 testing, which involves clinical trials designed to further assess drug safety and effectiveness and may require testing and surveillance programs to monitor the safety of approved products that have been commercialized.

Post-Approval Requirements

Any biologic products for which we or our collaborators receive FDA approvals are subject to continuing regulation by the FDA, including, among other things, cGMP compliance for product manufacture, record-keeping requirements, reporting of adverse experiences with the product, providing the FDA with updated safety and efficacy information, product sampling and distribution requirements, complying with certain electronic records and signature requirements, and complying with FDA promotion and advertising requirements, which include, among others, restrictions on direct-to-consumer advertising, promoting biologics for uses or in patient populations that are not described in the product’s approved labeling (known as “off-label use”), industry-sponsored scientific and educational activities, and promotional activities involving the internet. Failure to comply with these or other FDA requirements can subject a manufacturer to possible legal or regulatory action, such as product reclass, warning letters, suspension of manufacturing, seizure of product, injunctive action, mandated corrective advertising or communications with healthcare professionals, possible civil or criminal penalties, or other negative consequences, including adverse publicity.

U.S. Patent Term Restoration and Marketing Exclusivity

Depending upon the timing, duration and specifics of the FDA approval of any of our biologic product candidates, we may apply for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years for one patent per product as compensation for patent term lost during

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product development and the FDA regulatory review process of that product. The U.S. Patent and Trademark Office, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration.

Market exclusivity provisions under the FDCA can also delay the submission or the approval of certain applications of other companies seeking to reference another company’s BLA. Specifically, the Biologics Price Competition and Innovation Act established an abbreviated pathway for the approval of biosimilar and interchangeable biological products generally not earlier than 12 years after the original BLA approval. The abbreviated regulatory pathway establishes legal authority for the FDA to review and approve biosimilar biologics, including the possible designation of a biosimilar as “interchangeable” based on their similarity to existing brand product.

Pharmaceutical Coverage, Pricing and Reimbursement

The cost of pharmaceuticals continues to generate substantial governmental and third-party payor interest. We expect that the pharmaceutical industry will experience pricing pressures due to the trend toward managed healthcare, the increasing influence of managed care organizations and additional legislative proposals.

Healthcare Reform

In the United States and foreign jurisdictions, there have been and will continue to be a number of legislative and regulatory proposals to change the healthcare system in ways that could affect our ability to sell our product candidates profitably, once they are approved for sale. Among policy makers and payors in the United States and elsewhere, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality and/or expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives.

Other Healthcare Laws and Compliance Requirements

In the United States, the research, manufacturing, distribution, sale and promotion of drug products and medical devices are potentially subject to regulation by various federal, state and local authorities in addition to the FDA, including the Centers for Medicare & Medicaid Services, other divisions of Health and Human Services (e.g., the Office of Inspector General), the U.S. Department of Justice, state Attorneys General, and other state and local government agencies.

Europe / Rest of World Government Regulation

In addition to regulations in the United States, we, and our collaborators, will be subject to a variety of regulations in other jurisdictions governing, among other things, clinical trials and any commercial sales, marketing and distribution of our products, similar or more stringent than the U.S. laws.

Whether or not we, or our collaborators, obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical trials or marketing of the product in those countries. The requirements and process governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country. In addition, we and our collaborators may be subject to foreign laws and regulations and other compliance requirements, including, without limitation, anti-kickback laws, false claims laws and other fraud and abuse laws, as well as laws and regulations requiring transparency of pricing and marketing information and governing the privacy and security of health information, such as the European Union’s Directive 95/46 on the Protection of Individuals with regard to the Processing of Personal Data.

If we, or our collaborators, fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

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Corporate Information

We were incorporated in California in August 1997 under the name Xencor. In September 2004, we reincorporated in the state of Delaware under the name Xencor, Inc. Our principal offices are located at 111 West Lemon Avenue, Monrovia, CA 91016, and our telephone number is (626) 305-5900. Our website address is www.xencor.com. Our website and the information contained on, or that can be accessed through, the website will not be deemed to be incorporated by reference in and are not considered part of this Annual Report. Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to reports filed or furnished pursuant to Section 13(a) and 15(d) of the Securities Exchange Act of 1934, as amended, are available free of charge on the Investor Relations portion of our web site at www.xencor.com as soon as reasonably practical after we electronically file such material with, or furnish it to, the Securities and Exchange Commission (SEC). The SEC maintains an internet site at www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC.

Item 1A. Risk Factors.

Summary of Risk Factors

We are subject to a number of risks that if realized could materially harm our business, prospects, operating results, and financial condition. Some of the more significant risks and uncertainties we face include those summarized below. The summary below is not exhaustive and is qualified by reference to the full set of risk factors set forth in this “Risk Factors” section. Please carefully consider all of the information in this Form 10-K, including the full set of risks set forth in this

“Risk Factors” section, and in our other filings with the U.S. Securities and Exchange Commission before making an investment decision regarding Xencor.

We have reviewed our risk factors and categorized them into five specific categories:

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3. Risks related to our intellectual property. These risks include:

4. Risks related to our dependence on third parties. These risks include:

5. Risks related to our industry. These risks include:

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Risks Related to Our Unique and Specific Business Operations as a Small Biotechnology Company

Our success depends on our ability to use and expand our XmAb technology platform to build a pipeline of product candidates and develop marketable products. We cannot be certain our candidates will receive regulatory approval or be successfully commercialized.

We use our proprietary XmAb technology platform to develop engineered antibodies, with an initial focus on four properties: immune inhibition, cytotoxicity, extended half-life and most recently, heterodimeric Fc domains enabling molecules with dual target binding. This platform has led to our current pipeline of candidates as well as the other programs that utilize our technology and that are being developed by our partners and licensees. While we believe our preclinical and clinical data to date, together with our established partnerships, has validated our platform to a degree, most of the programs are in early stages of development. Although drug candidates incorporating our Fc technology, or Fc candidates, have been approved by the FDA, other product candidates have not yet been, and may never lead to, approved or marketable therapeutic antibody products. Even if we are successful in continuing to build our pipeline, the potential candidates that we identify may not be suitable for clinical development, including as a result of their harmful side effects, limited efficacy or other characteristics that indicate that they are unlikely to receive marketing approval and achieve market acceptance. If we do not successfully develop and commercialize product candidates, we may not be able to obtain product or partnership revenues in future periods, which would adversely affect our business, prospects, financial condition and results of operations.

The clinical development stage of our operations may make it difficult for you to evaluate the success of our business to date and to assess our future viability.

Our operations to date have been limited to raising capital, staffing our company, developing our proprietary XmAb technology platform, identifying potential product candidates, conducting preclinical studies and clinical trials, developing partnerships and business planning. We have conducted, or are currently conducting, early phase clinical

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trials for several product candidates, but have not completed any late stage clinical trials for these or any other product candidate. We have not yet demonstrated our ability to successfully complete any pivotal clinical trials, obtain regulatory approvals, manufacture a commercial scale product, or arrange for a third party to do so on our behalf, or conduct sales and marketing activities necessary for successful product commercialization. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we were further advanced in development of our product candidates.

In addition, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors. We believe we will need to transition from a company with a research and development focus to a company capable of supporting commercial activities. We may not be successful in this transition.

We expect our financial condition and operating results to continue to fluctuate significantly from quarter to quarter and year to year due to a variety of factors, many of which are beyond our control. Accordingly, you should not rely upon the results of any quarterly or annual periods as indications of future operating performance.

Preliminary, interim, and topline data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may publicly disclose preliminary, interim or topline data from our clinical trials. These updates are based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. Additionally, interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Therefore, positive interim results in any ongoing clinical trial may not be predictive of such results in the completed study or trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As a result, the preliminary results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. Preliminary data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. As a result, preliminary, interim or topline data should be viewed with caution until the final data are available. In addition, we may report interim analyses of only certain endpoints rather than all endpoints. Adverse changes between preliminary or interim data and final data could significantly harm our business and prospects. Further, additional disclosure of interim data by us or by our competitors in the future could result in volatility in the price of our common stock. See the description of risks under the heading “Risks Specifically Related to Our Financial Position, Capital Requirements and Ownership of Our Common Stock” for more disclosure related to the risk of volatility in our stock price.

Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is typically selected from a more extensive amount of available information. You or others may not agree with what we determine is the material or otherwise appropriate information to include in our disclosure, and any information we determine not to disclose may ultimately be deemed significant with respect to future decisions, conclusions, views, activities or otherwise regarding a particular product, product candidate or our business. If the preliminary or topline data that we report differ from late, final or actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize our product candidates may be harmed, which could harm our business, financial condition, results of operations and prospects.

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The COVID-19 pandemic and the future outbreak of other highly infectious or contagious diseases, could materially and adversely impact or disrupt our business and our financial condition, results of operations, cash flows and performance.

On March 11, 2020, the World Health Organization (WHO) declared the rapid spread of COVID-19 a global pandemic, and on March 19, 2020, the Governor of the State of California, where we are headquartered and where our principal place of business is located, implemented a mandatory stay at home order for residents working in non-critical businesses.

While we have managed to maintain our operations during the COVID-19 pandemic, additional developments with this pandemic or another epidemic or pandemic, could cause significant disruptions to our business operations, business operations of our partners, on whom we rely for potential revenue, and product development collaborations; operations of our third-party manufacturers and contract research organizations (CROs), on which we rely to conduct our clinical trials; and to our clinical trials, including as a result of significant restrictions or bans on travel into and within the countries in which our manufacturers produce our product candidates or where we conduct our clinical trials. Such disruptions could impede, delay, limit or prevent our employees and CROs from continuing research and development activities.

Although the COVID-19 pandemic has not materially affected our clinical development for the year ended December 31, 2021, certain of our clinical programs have seen slower enrollment and there have also been delays in initiating new studies as a result of the COVID-19 pandemic. These delays are not seen across all our trials and are specific to certain trials enrolling at certain sites. In the future, the COVID-19 pandemic could further adversely affect our and our partners’ ability to enroll and recruit patients in current and future clinical trials. Our success is dependent on our ability and the ability of our partners to advance our wholly-owned and partnered development programs into later stages of clinical development. Many pharmaceutical and biotechnology companies have indicated that their clinical trials will be delayed and enrollment of current and ongoing trials will suffer as a result of the COVID-19 pandemic. Completion of our ongoing clinical and preclinical studies or commencement of new clinical trials could be impeded, delayed, limited or prevented by the effects of the COVID-19 pandemic and related restrictions including negative effects on the production, delivery or release of our product candidates to our clinical trial sites, as participation by our clinical trial investigators, patients or other critical staff, which to could delay data collection, analysis and other related activities, any of which could cause delay or denial of regulatory approval of our product candidates. The delay and impact on enrollment cannot be determined at this time and will depend on the length and severity of the COVID-19 pandemic. Continued delays on our clinical and preclinical studies or trials will increase our costs and expenses and seriously harm our operations and financial condition, which will adversely affect our business.

The COVID-19 pandemic could also potentially affect the business of the FDA as well as other health regulatory authorities, which could result in delays in our communications with these authorities and ultimately in the ability for us and our partners to have drug products approved.

The COVID-19 pandemic and mitigation measures also have had and may continue to have an adverse impact on global economic conditions which could have an adverse effect on our business and financial condition, including impairment of our ability to raise capital when needed. The trading prices for biopharmaceutical companies’ stock, including our common shares have been highly volatile as a result of the COVID-19 pandemic. In addition, a recession, depression, or other sustained adverse market event resulting from the COVID-19 pandemic could materially and adversely affect our business and the value of our common shares.

The COVID-19 pandemic could potentially affect our partnerships and collaborations which provide us with revenue and non-dilutive payments in the form of upfront payments, milestone payments, royalties, and cost-sharing of co-development programs. If our partners’ and collaborators’ operations are severely affected by the COVID-19 pandemic, it will adversely affect our future potential revenue from such partners and collaborators.

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We have required most of our employees, including all of our administrative employees, to work remotely, restricted on-site staff to only those employees that must perform essential activities that must be completed on-site and limited the number of staff allowed in our laboratory and offices. These changes may negatively impact productivity, or disrupt, delay, or otherwise adversely impact our business. In addition, this could increase our cyber security risk, create data accessibility concerns, and make us more susceptible to communication disruptions, any of which could adversely impact our business operations. When we reopen our facilities, we could encounter delays in connection with implementing precautionary measures to mitigate the risk of exposing our facilities and employees to COVID-19.

The COVID-19 pandemic could adversely affect our supply chain for our research, development, and clinical programs. We rely on third party vendors for research supplies, development activities including manufacturing of drug product for our clinical studies and testing of drug material. In the third quarter of 2020, several manufacturing vendors notified us of critical supply shortages which delayed the development timelines for our earlier stage development programs by three to six months. We currently do not expect these supply shortages to delay the timelines for our programs that are already in clinical studies. However, if this supply disruption continues or becomes more acute, it will extend the timelines for advancing our earlier stage programs further and could also delay the current timelines for advancing our existing clinical programs. If any other vendors in our supply chain of products or services are also severely affected from the COVID-19 pandemic, it will adversely affect our ability to continue our research and development activities and also continue our clinical trial activities.

The COVID-19 pandemic continues to rapidly evolve. Its ultimate impact on our business operations is highly uncertain and subject to change that will depend on future developments, which cannot be accurately predicted, including the duration of the COVID-19 pandemic, additional or modified government actions, new information that will emerge concerning the severity and impact of COVID-19 and the actions taken to address its impact in the short and long term, among others. We do not yet know the full extent of potential delays or impacts on our business, our clinical trials, our research programs, healthcare systems or the global economy. We will continue to monitor the situation closely.

Risks Specifically Related to Our Financial Position, Capital Requirements and Ownership of Our Common Stock

We have incurred significant losses since our inception and anticipate that we will continue to incur significant losses for the foreseeable future.

We are a clinical-stage biopharmaceutical company. To date, we have financed our operations primarily through equity financings and our research and development licensing agreements and have incurred significant operating losses since our inception in 1997. For the year ended December 31, 2021, we generated net income of $82.6 million and as of December 31, 2021, we had an accumulated deficit of $283.1 million. We expect to incur losses in future years as we execute our plan to continue our discovery, research and development activities, including the ongoing and planned clinical development of our antibody product candidates, and incur the additional costs of operating as a public company. We are unable to predict the extent of any future losses or when we will become profitable, if ever. Even if we do achieve profitability, we may not be able to sustain or increase profitability on an ongoing basis which would adversely affect our business, prospects, financial condition, and results of operations.

Biopharmaceutical product development is a highly speculative undertaking and involves a substantial degree of uncertainty. We have never generated any revenue from product sales and may never be profitable.

We have devoted substantially all of our financial resources and efforts to developing our proprietary XmAb technology platform, identifying potential product candidates and conducting preclinical studies and clinical trials. We are still in the early stages of developing our product candidates, and we have not completed development of any of our wholly-owned products. Our revenue to date has been primarily revenue from the license of our proprietary XmAb technology platform and drug candidates for the development of product candidates by others or revenue from our partners. Our ability to generate revenue and achieve profitability depends in large part on our ability, alone or with partners, to achieve milestones and to successfully complete the development of, obtain the necessary regulatory approvals for, and commercialize and market, product candidates. We do not anticipate generating revenues from sales

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of our own products in the foreseeable future that will provide sufficient proceeds to fund our operations on an ongoing basis.

Our ability to generate future revenues from licensing our proprietary XmAb technologies and drug candidates depends heavily on our and our partners’ success in advancing drug candidates that they have licensed from us or developed using one of our technologies. Our partners face the same development, regulatory and market risk for advancing their drug candidates and their ability to successfully advance these partnered programs will affect potential milestones and royalties we could earn under our collaboration agreements. Further, our partners may decide not to pursue, or decide to deprioritize our programs due to changing priorities which could affect our future potential revenue from such arrangements.

Because of the numerous risks and uncertainties associated with biologic product development, we are unable to predict the timing or amount of increased expenses and when we will be able to achieve or maintain profitability, if ever. In addition, our expenses could increase beyond expectations if we are required by the FDA, or foreign regulatory agencies, to perform studies and trials in addition to those that we currently anticipate, or if there are any delays in our or our partners’ completion of clinical trials or delays in the development of any of our product candidates. Even if we or our partners are able to generate revenues from the sale of any approved products, we may not become profitable and may need to obtain additional funding to continue operations, which may not be available to us on favorable terms, if at all.

We will require additional financing and may be unable to raise sufficient capital, which could lead us to delay, reduce or abandon research and development programs or commercialization.

As of December 31, 2021, we had $664.1 million in cash, cash equivalents, marketable debt securities, and receivables. We expect our expenses to increase in connection with our ongoing development activities, including the continued development of our pipeline of bispecific antibody and cytokine drug candidates and other research activities. Identifying potential product candidates and conducting preclinical testing and clinical trials are time-consuming, expensive, and uncertain processes that take years to complete, and we or our partners may never generate the necessary data or results required to obtain regulatory approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success.

Our commercial revenues, if any, will be derived from sales of products that we do not expect to be commercially available for many years, if at all. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or eliminate our research and development programs or any future commercialization efforts.

We believe our existing cash, cash equivalents and marketable securities, together with interest thereon and expected milestones and royalty payments will be sufficient to fund our operations through the end of 2025. However, changing circumstances or inaccurate estimates by us may cause us to use capital significantly faster than we currently anticipate, and we may need to spend more money than currently expected because of circumstances beyond our control. We do not have sufficient cash to complete the clinical development of any of our product candidates and will require additional funding to complete the development activities required for regulatory approval of our current product candidates or any other future product candidates that we develop independently. Because successful development of our product candidates is uncertain, we are unable to estimate the actual funds we will require to complete research and development and commercialize our product candidates. Adequate additional financing may not be available to us on acceptable terms, or at all. In addition, we may seek additional capital due to favorable market conditions or strategic considerations; even if we believe we have sufficient funds for our current or future operating plans. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or eliminate our research and development programs or any future commercialization efforts.

The market price of our common stock is likely to be highly volatile, and you could lose all or part of your investment.

Prior to our initial public offering (IPO), there was no public market for our common stock. The trading price of our common stock is likely to be volatile. Since our IPO, the trading price of our common stock has ranged from a low

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of approximately $5.75 to a high of approximately $58.345. Our stock price could be subject to wide fluctuations in response to a variety of factors, including the following:

2. inability to obtain additional funding;

3. changes in laws or regulations applicable to our products;

5. adverse regulatory decisions;

6. changes in the structure of healthcare payment systems;

7. introduction of new products or technologies by our competitors;

12. additions or departures of key scientific or management personnel;

13. significant lawsuits, including patent or stockholder litigation;

14. changes in the market valuations of similar companies;

15. sales of our common stock by us or our stockholders in the future; and

16. trading volume of our common stock.

In addition, the stock market in general, and the Nasdaq Global Market and biotechnology companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance.

In the past, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for us because biopharmaceutical companies have experienced significant stock price volatility in recent years. If we face such litigation, it could result in substantial costs and a diversion of management’s attention and resources, which could harm our business.

Our principal stockholders, directors and management own a significant percentage of our stock and will be able to exert significant control over matters subject to stockholder approval.

Based on information available to us as of December 31, 2021 our executive officers, directors, 5% stockholders and their affiliates beneficially owned, as a group, approximately 70% of our voting stock.

Therefore, our officers, directors and 5% stockholders and their affiliates will have the ability to influence us through this ownership position and so long as they continue to beneficially own a significant amount of our outstanding voting stock. These stockholders may be able to determine all matters requiring stockholder approval and this concentration of ownership may deprive other stockholders from realizing the true value of our common stock. For example, these stockholders, acting together, may be able to control elections of directors, amendments of our organizational documents, or approval of any merger, sale of assets, or other major corporate transaction. This may

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prevent or discourage unsolicited acquisition proposals, offers for our common stock or other transactions or arrangements that you may believe are in your best interest as one of our stockholders.

Raising additional funds through debt or equity financing may be dilutive or restrict our operations and raising funds through licensing may require us to relinquish rights to our technology or product candidates.

To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of those securities could result in substantial dilution for our current stockholders and the terms may include liquidation or other preferences that adversely affect the rights of our current stockholders. Existing stockholders may not agree with our financing plans or the terms of such financings. If we are unable to obtain additional funding on required timelines, we may be required to:

1. seek collaborators for one or more of our product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be available;

2. relinquish or license on unfavorable terms our rights to technologies or product candidates that we otherwise would seek to develop or commercialize ourselves; or

3. significantly curtail one or more of our research or development programs or cease operations altogether. Additional funding may not be available to us on acceptable terms, or at all.

Future sales and issuances of our common stock or rights to purchase common stock, including pursuant to our equity incentive plans, could result in additional dilution of the percentage ownership of our stockholders and could cause our stock price to fall.

We expect that significant additional capital will be needed in the future to continue our planned operations. To the extent we raise additional capital by issuing equity securities, our stockholders may experience substantial dilution. We may sell common stock, convertible securities, or other equity securities in one or more transactions at prices and in a manner, we determine from time to time. These sales may also result in material dilution to our existing stockholders, and new investors could gain rights superior to our existing stockholders.

Pursuant to our 2013 equity incentive plan (2013 plan), subject to board approval, our management is authorized to grant stock options and other equity-based awards to our employees, directors and consultants. The number of shares available for future grant under the 2013 plan will automatically increase each year until 2023 by 4% of all shares of our capital stock outstanding as of December 31 of the prior calendar year, subject to the ability of our Board of Directors to take action to reduce the size of the increase in any given year. As of December 31, 2021, we had options to purchase 8,676,329 shares outstanding under our equity compensation plans. In addition, we are also authorized to grant equity awards, including stock options, to our employees, directors, and consultants, covering up to 13,122,238 shares of our common stock, pursuant to our equity compensation plans. We plan to register the number of shares available for issuance or subject to outstanding awards under our equity compensation plans. If our Board of Directors elects to increase the number of shares available for future grant by the maximum amount each year, our stockholders may experience additional dilution, which could cause our stock price to fall.

If our internal control over financial reporting is not effective, we may not be able to accurately report our financial results or file our periodic reports in a timely manner, which may cause investors to lose confidence in our reported financial information and may lead to a decline in our stock price.

Effective internal control over financial reporting is necessary for us to provide reliable financial reports in a timely manner. If we fail to adequately staff our accounting and finance function to address the additional demands that will be placed upon us as a public company, including the requirements of the Sarbanes-Oxley Act of 2002, or fail to maintain adequate internal control over financial reporting, it could prevent our management from concluding our internal control over financial reporting is effective and impair our ability to prevent material misstatements in our financial statements, which could cause our business to suffer.

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As a large accelerated filer, we are subject to additional internal control requirements of the Sarbanes-Oxley Act of 2002.

Sales of a substantial number of shares of our common stock by our existing stockholders in the public market could cause our stock price to fall.

If our existing stockholders sell, or indicate an intention to sell, substantial amounts of our common stock in the public market, the trading price of our common stock could decline. In addition, a substantial number of shares of common stock are subject to outstanding options that are or will become eligible for sale in the public market to the extent permitted by the provisions of various vesting schedules. If these additional shares of common stock are sold, or if it is perceived that they will be sold, in the public market, the trading price of our common stock could decline.

Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.

Our net operating loss (NOL) carryforwards generated in tax years ending on or prior to December 31, 2017, are only permitted to be carried forward for 20 years under applicable U.S. tax law. Under the Tax Cuts and Jobs Act of 2017 (TCJA), our federal NOLs generated in tax years ending after December 31, 2017, may be carried forward indefinitely, but the deductibility of such federal NOLs generated in tax years beginning after December 31, 2021, is limited. It is uncertain if and to what extent various states will conform to the TCJA. In addition, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, and corresponding provisions of state law, if a corporation undergoes an “ownership change,” which is generally defined as a greater than 50% change, by value, in its equity ownership over a three-year period, the corporation’s ability to use its pre-change NOL carryforwards and other pre-change U.S. tax attributes (such as research tax credits) to offset its post-change income or taxes may be limited. It is also possible that we have in the past undergone, and in the future may undergo, ownership changes that could result in additional limitations on our net operating loss and tax credit carryforwards.

As a result, our pre-2018 NOL carryforwards may expire prior to being used. Similar provisions of state tax law may also apply to limit our use of accumulated state tax attributes. In addition, at the state level, there may be periods during which the use of NOLs is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. As a result, if we earn net taxable income, we may be unable to use all or a material portion of our NOLs and other tax attributes, which could potentially result in increased future tax liability to us and adversely affect our future cash flows.

New federal and state income tax legislation may affect our current and future income tax liabilities

The TCJA changed the income tax treatment of research and development expenses which may result in additional federal and state tax liabilities. For tax years ended in December 31, 2022 and subsequent years, research and development costs must be capitalized and amortized over a period of years which could result in additional federal and state tax liabilities in 2022 and future years.

We do not intend to pay dividends on our common stock so any returns will be limited to the value of our stock.

We have never declared or paid any cash dividend on our common stock. We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. Any return to stockholders will therefore be limited to the appreciation of their stock.

Provisions in our amended and restated certificate of incorporation and bylaws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us or increase the cost of acquiring us, even if doing so would benefit our stockholders or remove our current management.

Some provisions of our charter documents and Delaware law may have anti-takeover effects that could discourage an acquisition of us by others, even if an acquisition would be beneficial to our stockholders and may prevent attempts by our stockholders to replace or remove our current management. These provisions include:

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These provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our Board of Directors, which is responsible for appointing the members of our management. In addition, we are subject to Section 203 of the Delaware General Corporation Law, which generally prohibits a Delaware corporation from engaging in any of a broad range of business combinations with an interested stockholder for a period of three years following the date on which the stockholder became an interested stockholder, unless such transactions are approved by our Board of Directors. This provision could have the effect of delaying or preventing a change of control, whether or not it is desired by or beneficial to our stockholders. Further, other provisions of Delaware law may also discourage, delay, or prevent someone from acquiring us or merging with us. Any provision of our certificate of incorporation or bylaws or Delaware law that has the effect of delaying or deterring change in control could limit the opportunity for our stockholders to receive a premium for their shares of our common stock, and could also affect the price that some investors are willing to pay for our common stock.

Requirements associated with being a public reporting company will continue to increase our costs significantly, as well as divert significant company resources and management attention.

We have been subject to the reporting requirements of the Exchange Act and the other rules and regulations of the Securities and Exchange Commission (SEC) since December 2013. Effective for the year-ended December 31, 2016, we became a large accelerated filer and are subject to additional internal control and SEC reporting obligations. Compliance with the various reporting and other requirements applicable to public reporting companies requires considerable time, attention of management, and financial resources.

Further, the listing requirements of The Nasdaq Global Market require that we satisfy certain corporate governance requirements relating to director independence, distributing annual and interim reports, stockholder meetings, approvals, and voting, soliciting proxies, conflicts of interest and a code of conduct. Our management and other personnel need to devote a substantial amount of time to ensure that we comply with all of these requirements. Moreover, the reporting requirements, rules and regulations increase our legal and financial compliance costs and also make some activities more time-consuming and costly. These reporting requirements, rules, and regulations, coupled with the increase in potential litigation exposure associated with being a public company, could also make it more difficult for us to attract and retain qualified persons to serve on our Board of Directors or board committees or to serve as executive officers, or to obtain certain types of insurance, including directors’ and officers’ insurance, on acceptable terms.

In addition, being a public company could make it more difficult or more costly for us to obtain certain types of insurance, including directors’ and officers’ liability insurance, and we may be forced to accept reduced policy limits and coverage or incur substantially higher costs to obtain the same or similar coverage. The impact of these events could also make it more difficult for us to attract and retain qualified persons to serve on our Board of Directors, our Board committees, or as executive officers.

Any changes we make to comply with these obligations may not be sufficient to allow us to satisfy our obligations as a public company on a timely basis, or at all.

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Risks Related to Our Intellectual Property

If we are unable to obtain, maintain and enforce intellectual property protection covering our products, others may be able to make, use or sell products substantially the same as ours, which could adversely affect our ability to compete in the market.

Our commercial success depends, in part, on our ability to obtain, maintain and enforce patents, trade secrets, trademarks and other intellectual property rights and to operate without having third parties infringe, misappropriate or circumvent the rights that we own or license. The value of many of our partnered licensing arrangements is based on the underlying intellectual property and related patents. If we are unable to obtain, maintain and enforce intellectual property protection covering our products or underlying technologies, others may be able to make, use or sell products that are substantially the same as ours without incurring the sizeable development and licensing costs that we have incurred, which would adversely affect our ability to compete in the market. As of December 31, 2021, we held over 1,300 issued patents and pending patent applications. We file patent applications in the United States, Canada, Japan, Europe and other major markets either directly or via the Patent Cooperation Treaty. Our ability to stop third parties from making, using, selling, offering to sell or importing our product candidates is dependent upon the extent to which we have rights under valid and enforceable patents or trade secrets that cover these activities. However, the patent positions of biopharmaceutical companies, including ours, can be highly uncertain and involve complex legal and factual questions for which important legal principles remain unresolved. No consistent policy regarding the breadth of claims allowed in patents in these fields has emerged to date in the United States. The U.S. patent laws have recently changed, there have been changes regarding how patent laws are interpreted, and the U.S. Patent and Trademark Office (the PTO) has also implemented changes to the patent system. Some of these changes are currently being litigated, and we cannot accurately determine the outcome of any such proceedings or predict future changes in the interpretation of patent laws or changes to patent laws which might be enacted into law. Those changes may materially affect our patents, our ability to obtain patents or the patents and applications of our collaborators and licensors. The patent situation in the biopharmaceutical industry outside the United States is even more uncertain. Therefore, there is no assurance that our pending patent applications will result in the issuance of patents or that we will develop additional proprietary products which are patentable. Moreover, patents issued or to be issued to us may not provide us with any competitive advantage. Our patent position is subject to numerous additional risks, including the following:

2. our pending patent applications may not result in issued patents;

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15. we may not develop additional proprietary technologies that are patentable.

Any of these factors could hurt our ability to gain full patent protection for our products. Registered trademarks and trademark applications in the United States and other countries are subject to similar risks as described above for patents and patent applications, in addition to the risks described below.

Many of our product development partnership agreements are complex and may call for licensing or cross-licensing of potentially blocking patents, know-how or intellectual property. Due to the potential overlap of data, know-how and intellectual property rights there can be no assurance that one of our collaborators will not dispute our right to use, license or distribute data, know-how or other intellectual property rights, and this may potentially lead to disputes, liability or termination of a program. There are no assurances that our actions or the actions of our collaborators would not lead to disputes or cause us to default with other collaborators. For example, we may become involved in disputes with our collaborators relating to the ownership of intellectual property developed in the course of the partnership. We also cannot be certain that a collaborator will not challenge the validity or enforceability of the patents we license.

We cannot be certain that any country’s patent and/or trademark office will not implement new rules which could seriously affect how we draft, file, prosecute and/or maintain patents, trademarks and patent and trademark applications. We cannot be certain that increasing costs for drafting, filing, prosecuting and maintaining patents, trademarks and patent and trademark applications will not restrict our ability to file for patent protection. For example, we may elect not to seek patent protection in certain jurisdictions or for certain inventions in order to save costs. We may be forced to abandon or return the rights to specific patents due to a lack of financial resources.

We intend to file applications for trademark registrations in connection with our product candidates in various jurisdictions, including the United States. No assurance can be given that any of our trademark applications will be registered in the United States or elsewhere, or that the use of any registered or unregistered trademarks will confer a competitive advantage in the marketplace. Furthermore, even if we are successful in our trademark registrations, the FDA and regulatory authorities in other countries have their own process for drug nomenclature and their own views concerning appropriate proprietary names. No assurance can be given that the FDA or any other regulatory authority will approve of any of our trademarks or will not request reconsideration of one of our trademarks at some time in the future. The loss, abandonment, or cancellation of any of our trademarks or trademark applications could negatively affect the success of the product candidates to which they relate.

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We have in-licensed, and may in the future in-license, a portion of our intellectual property, and, if we fail to comply with our obligations under these arrangements, we could lose such intellectual property rights or owe damages to the licensor of such intellectual property.

We currently rely, and may in the future rely, on certain intellectual property rights licensed from third parties to protect our technology and certain product candidates, and we may enter into additional license agreements in the future. As part of our discovery and development activities, we routinely evaluate in-licenses from academic and research institutions. We have sublicensed certain intellectual property rights related to our CD3 bispecific technology from a third party, and we have licensed certain intellectual property rights from a third party related to our tidutamab product candidate. We also license certain rights to the underlying cell lines for all our product candidates from third parties. Under these licenses, we have no right to control patent prosecution of the intellectual property or to enforce the patents, and as such the licensed rights may not be adequately maintained by the licensors. The termination of these or other licenses could also prevent us from commercializing product candidates covered by the licensed intellectual property.

Our existing license agreements impose, and we expect that future license agreements will impose, various diligence, milestone payment, royalty and other obligations on us. If there is any conflict, dispute, disagreement or issue of non-performance between us and our licensing partners regarding our rights or obligations under the license agreements, including any such conflict, dispute or disagreement arising from our failure to satisfy payment obligations under any such agreement, we may owe damages, our licensor may have a right to terminate the affected license, and our and our partners' ability to utilize the affected intellectual property in our drug discovery and development efforts, and our ability to enter into collaboration or marketing agreements for an affected product or therapeutic candidate, may be adversely affected.

We may be required to reduce the scope of our intellectual property due to third-party intellectual property claims.

Our competitors may have filed, and may in the future file, patent applications covering technology similar to ours. Any such patent application may have priority over our patent applications, which could further require us to obtain rights to issued patents covering such technologies. If another party has filed a U.S. patent application on inventions similar to ours that claims priority to an application filed prior to March 16, 2013, we may have to participate in an interference proceeding declared by the PTO to determine priority of invention in the United States. The costs of these proceedings could be substantial, and it is possible that such efforts would be unsuccessful if, unbeknownst to us, the other party had independently arrived at the same or similar invention prior to our own invention, resulting in a loss of our U.S. patent position with respect to such inventions. In addition, changes enacted on March 15, 2013 to the U.S. patent laws under the America Invents Act resulted in the United States changing from a “first to invent” country to a “first to file” country. As a result, we may lose the ability to obtain a patent if a third-party files with the PTO first and could become involved in proceedings before the PTO to resolve disputes related to inventorship. We may also become involved in similar proceedings in other jurisdictions.

Furthermore, changes in U.S. patent law under the America Invents Act allows for post-issuance challenges to U.S. patents, including ex parte reexaminations, inter parte reviews and post-grant review. There is significant uncertainty as to how the new laws will be applied and if our U.S. patents are challenged using such procedures, we may not prevail, possibly resulting in altered or diminished claim scope or loss of patent rights altogether. Similarly, some countries, notably members of the European Union, also have post grant opposition proceedings that can result in changes in scope and/or cancellation of patent claims.

Our products could infringe patents and other property rights of others, which may result in costly litigation and, if we are not successful, could cause us to pay substantial damages or limit our ability to commercialize our products, which could have a material adverse effect on our business.

Our commercial success depends upon our ability, and the ability of our collaborators, to develop, manufacture, market and sell our product candidates and use our proprietary technologies without infringing the patents and other proprietary rights of third parties. There is considerable intellectual property litigation in the biotechnology and pharmaceutical industries. For example, we are aware of issued patents owned by Merus B.V. (Merus) that may relate to

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and claim components of our bispecific antibody product candidates and partnered bispecific product candidates, including plamotamab, tidutamab, vudalimab, XmAb104, XmAb841, and XmAb819 will putatively expire in 2033. We are additionally aware of several patents and pending applications directed to the use of IL-15 fused with Fc domains, and in some cases in combination with targeting domains, that might be relevant to XmAb306, with putative expirations ranging from 2025 to later than 2032. It is possible that these terms could be extended, for example, as a result of patent term restoration to compensate for regulatory delays. While we believe that our current development of these candidates currently falls into the “safe harbor” of non-infringement under 35 U.S.C. §271(e)(1), this protection terminates upon commercialization. In addition, there can be no assurance that our interpretation of this statutory exemption would be upheld. We believe there exists reasonable arguments of invalidity for the Merus patents and the IL-15 patents; however, we cannot assure that if challenged in litigation for infringement of these patents that we would prevail. In order to successfully challenge the validity of any issued U.S. patent, we would need to overcome a presumption of validity. This burden is a high one requiring us to present clear and convincing evidence as to the invalidity of such claims. There is no assurance that a court would find these claims to be invalid or not infringed.

In addition, as the biopharmaceutical industry expands and more patents are issued, the risk increases that there may be patents issued to third parties that relate to our products and technology of which we are not aware or that we must challenge to continue our operations as currently contemplated. Our products may infringe or may be alleged to infringe these patents. Because some patent applications in the United States may be maintained in secrecy until the patents are issued, because patent applications in the United States and many foreign jurisdictions are typically not published until eighteen months after filing and because publications in the scientific literature often lag behind actual discoveries, we cannot be certain that others have not filed patents that may cover our technologies, our product candidates or their use. Additionally, pending patent applications which have been published can, subject to certain limitations, be later amended in a manner that could cover our technologies, our products or the use of our products. We may become party to, or threatened with, future adversarial proceedings or litigation regarding intellectual property rights with respect to our products and technology. Third parties may assert infringement claims against us based on existing patents or patents that may be granted in the future.

If we are sued for patent infringement, we would need to demonstrate that our products or methods either do not infringe the patent claims of the relevant patent or that the patent claims are invalid, and we may not be able to do this. Proving invalidity is difficult. For example, in the United States, proving invalidity requires a showing of clear and convincing evidence to overcome the presumption of validity enjoyed by issued patents. Even if we are successful in these proceedings, we may incur substantial costs and divert management’s time and attention in pursuing these proceedings, which could have a material adverse effect on us.

Any such claims are likely to be expensive to defend, and some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources.

If we are found to infringe a third party’s intellectual property rights, we could be required to obtain a license from such third party to continue developing and marketing our products and technology. We may also elect to enter into such a license in order to settle litigation or in order to resolve disputes prior to litigation. However, we may not be able to obtain any required license on commercially reasonable terms or at all. Even if we were able to obtain a license, it could be non-exclusive, thereby giving our competitors access to the same technologies licensed to us and could require us to make substantial royalty payments. We could also be forced, including by court order, to cease commercializing the infringing technology or product. In addition, we could be found liable for monetary damages, including treble damages and attorneys’ fees if we are found to have willfully infringed a patent. A finding of infringement could prevent us from commercializing our product candidates or force us to cease some of our business operations, which could materially harm our business. Claims that we have misappropriated the confidential information or trade secrets of third parties could have a similar negative impact on our business.

If we are not able to prevent disclosure of our trade secrets and other proprietary information, the value of our technology and products could be significantly diminished.

We rely on trade secret protection to protect our interests in proprietary know-how and in processes for which patents are difficult to obtain or enforce. We may not be able to protect our trade secrets adequately. We have a policy of

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requiring our consultants, advisors, and collaborators to enter into confidentiality agreements and our employees to enter into invention, non-disclosure and non-compete agreements. However, no assurance can be given that we have entered into appropriate agreements with all parties that have had access to our trade secrets, know-how or other proprietary information. There is also no assurance that such agreements will provide for a meaningful protection of our trade secrets, know-how or other proprietary information in the event of any unauthorized use or disclosure of information. Furthermore, we cannot provide assurance that any of our employees, consultants, contract personnel, or collaborators, either accidentally or through willful misconduct, will not cause serious damage to our programs and/or our strategy, for example by disclosing important trade secrets, know-how or proprietary information to our competitors. It is also possible that our trade secrets, know-how or other proprietary information could be obtained by third parties as a result of breaches of our physical or electronic security systems. Any disclosure of confidential data into the public domain or to third parties could allow our competitors to learn our trade secrets and use the information in competition against us. In addition, others may independently discover our trade secrets and proprietary information. Any action to enforce our rights is likely to be time consuming and expensive, and may ultimately be unsuccessful, or may result in a remedy that is not commercially valuable. These risks are accentuated in foreign countries where laws or law enforcement practices may not protect proprietary rights as fully as in the United States or Europe. Any unauthorized disclosure of our trade secrets or proprietary information could harm our competitive position.

If we do not obtain patent term extension and data exclusivity for any therapeutic candidates we develop, our business may be materially harmed.

Depending upon the timing, duration, and specifics of any FDA marketing approval of any therapeutic candidates we may develop, one or more of our owned or licensed U.S. patents may be eligible for limited patent term extension under the Hatch-Waxman Act. Similar extensions as compensation for patent term lost during regulatory review processes are also available in certain foreign countries and territories, such as in Europe under a Supplementary Patent Certificate. However, we may not be granted an extension in the United States and/or foreign countries and territories because of, for example, failing to exercise due diligence during the testing phase or regulatory review process, failing to apply within applicable deadlines, failing to apply prior to expiration of relevant patents, or otherwise failing to satisfy applicable requirements. Moreover, the applicable time period or the scope of patent protection afforded could be less than we request. If we are unable to obtain patent term extension or the term of any such extension is shorter than what we request or we fail to choose the most optimal patents to extend, our competitors may obtain approval of competing products following our patent expiration, and our business, financial condition, results of operations and prospects could be materially harmed.

Risks Related to Our Dependence on Third Parties

Our patent protection and prosecution for some of our product candidates is dependent on third parties.

While we normally seek and gain the right to fully prosecute the patents relating to our product candidates, there may be times when patents relating to our product candidates are controlled by our licensors.

We rely on third-party manufacturers for the manufacture of our XmAb-engineered antibodies. This entails a complex process and manufacturers often encounter difficulties in production. If we, or any of our third-party manufacturers, encounter any loss of our master cell banks or if any of our third-party manufacturers otherwise fail to comply with their contractual obligations, the development or commercialization of our product candidates could be delayed or stopped.

The manufacture of biopharmaceutical products is complex and requires significant expertise and capital investment, including the development of advanced manufacturing techniques and process controls. We and our contract manufacturers must comply with cGMP regulations and guidelines. Manufacturers of biopharmaceutical products often encounter difficulties in production, particularly in scaling up and validating initial production and contamination. These problems include difficulties with production costs and yields, quality control, including stability of the product, quality assurance testing, operator error, shortages of qualified personnel, as well as compliance with strictly enforced federal, state and foreign regulations. Furthermore, if microbial, viral or other contaminations are discovered in our products or

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in the manufacturing facilities in which our products are made, such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination.

All of our XmAb engineered antibodies are manufactured by starting with cells which are stored in a cell bank. We have one master cell bank for each antibody manufactured in accordance with cGMP and multiple working cell banks and believe we would have adequate backup should any cell bank be lost in a catastrophic event. However, it is possible that we could lose multiple cell banks and have our manufacturing severely impacted by the need to replace the cell banks.

We cannot assure you that any stability or other issues relating to the manufacture of any of our product candidates or products will not occur in the future. Additionally, our manufacturer may experience manufacturing difficulties due to resource constraints or as a result of labor disputes or unstable political environments. If our manufacturers were to encounter any of these difficulties, or otherwise fail to comply with their contractual obligations, our ability to provide any product candidates to patients in clinical trials and products to patients, once approved, would be jeopardized. Any delay or interruption in the supply of clinical trial supplies could delay the completion of clinical trials, increase the costs associated with maintaining clinical trial programs and, depending upon the period of delay, require us to commence new clinical trials at additional expense or terminate clinical trials completely. Any adverse developments affecting clinical or commercial manufacturing of our product candidates or products may result in shipment delays, inventory shortages, lot failures, product withdrawals or recalls, or other interruptions in the supply of our product candidates or products. We may also have to take inventory write-offs and incur other charges and expenses for product candidates or products that fail to meet specifications, undertake costly remediation efforts or seek more costly manufacturing alternatives. Accordingly, failures or difficulties faced at any level of our supply chain could materially adversely affect our business and delay or impede the development and commercialization of any of our product candidates or products and could have a material adverse effect on our business, prospects, financial condition and results of operations.

Our existing partnerships are important to our business, and future partnerships may also be important to us. If we are unable to maintain any of these partnerships, or if these partnerships are not successful, our business could be adversely affected.

Because developing biologics products, conducting clinical trials, obtaining regulatory approval, establishing manufacturing capabilities and marketing approved products are expensive, we have entered into partnerships, and may seek to enter into additional partnerships, with companies that have more resources and experience than us, and we may become dependent upon the establishment and successful implementation of partnership agreements.

XNCR US Equity

XNCR · 10-K · period ended 2021-12-31

Item 1. Business.

Item 1A. Risk Factors.

XNCR US Equity☆

XNCR · 10-K · period ended 2021-12-31

Item 1. Business.

Item 1A. Risk Factors.

XNCR US Equity