Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of financial condition and operating results together with our consolidated financial statements and the related notes and other financial information included elsewhere in this Annual Report on Form 10-K. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report on Form 10-K contains forward-looking statements based upon current plans, expectations and beliefs involving significant risks and uncertainties. As a result of many important factors, including those set forth under “Risk Factors” and elsewhere in this Annual Report on Form 10-K, our actual results may differ materially from those anticipated in these forward-looking statements. For convenience of presentation some of the numbers have been rounded in the text below.

A discussion regarding our financial condition and results of operations for the years ended December 31, 2025 and 2024, including a year-to-year comparison between 2025 and 2024, is presented below. For a discussion regarding our financial condition and results of operations for the year ended December 31, 2023, including a year-to-year comparison between 2024 and 2023, refer to Part II, Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K for the year ended December 31, 2024 filed on March 26, 2025.

Overview

We are a clinical-stage biopharmaceutical company developing azenosertib (ZN-c3), an investigational, potentially first-in-class and best-in-class WEE1 inhibitor, for patients with ovarian cancer and other tumor types. In clinical trials, azenosertib has been well tolerated and has demonstrated anti-tumor activity as a single agent across multiple tumor types. We are currently focused on advancing the clinical development of azenosertib in Cyclin E1-positive platinum-resistant ovarian cancer, or PROC. We believe that our DENALI (ZN-c3-005) Part 2 clinical trial of azenosertib in patients with Cyclin E1-positive PROC, if successful, has the potential to support an accelerated approval, subject to U.S. Food and Drug Administration, or FDA, review. Azenosertib also has broad franchise potential beyond Cyclin E1-positive PROC. We exclusively in-license or solely own worldwide development and commercialization rights to azenosertib.

Azenosertib (WEE1 Inhibitor)

Mechanism of Action

Azenosertib is an investigational, potentially first-in-class and best-in-class oral, small molecule WEE1 inhibitor. The inhibition of WEE1, a DNA damage response kinase, drives cancer cells into mitosis without being able to repair damaged DNA, resulting in cell death and thereby preventing tumor growth and potentially causing tumor regression. We have designed azenosertib to have advantages over other investigational therapies targeting WEE1, including superior selectivity and pharmacokinetic, or PK, properties.

Cyclin E1 Expression as a Sensitive and Specific Predictive Biomarker

Cells with Cyclin E1 activation are exquisitely sensitive to WEE1 inhibition via azenosertib because Cyclin E1 activation further accelerates cancer cells into the DNA replication phase without adequate DNA repair. As a result, we have used retrospective analyses to establish Cyclin E1 as a sensitive and specific predictive biomarker that can be used to identify patients who might benefit from azenosertib. In addition, based on published retrospective analyses, Cyclin E1 alteration is a biomarker of poor prognosis and low benefit from standard-of-care single-agent chemotherapy in PROC patients.

We are working with a diagnostic partner to validate a companion diagnostic test that will identify patients with PROC that overexpress the Cyclin E1 protein using our proprietary immunohistochemistry, or IHC, cutoff. A prototype of this test is being used in DENALI Part 2 and is ready for use in our Phase 3 trial, ASPENOVA.

Market Opportunity

In 2022, the global ovarian cancer market was approximately $3 billion, with significant growth expected over the next several years. PROC is a subset of the ovarian cancer market. Based on our analysis utilizing our IHC cutoff, we estimate that approximately 50% of PROC patients overexpress Cyclin E1 protein, which accounts for approximately 21,500 patients on an annual basis in the United States, EU4 (France, Germany, Italy, Spain) and the United Kingdom, based on 2024 estimates. As a result, we believe there is a large market opportunity for azenosertib in Cyclin E1-positive PROC patients. Moreover, the successful launch of mirvetuximab in PROC patients with high folate receptor alpha, or FRα-high, expression underscores the demand for biomarker-directed therapies for PROC patients. The limited overlap between FRα-high PROC patients and those

that have Cyclin E1 overexpression is estimated to be less than 20%, which highlights the significant unmet need in patients with Cyclin E1-positive PROC.

We believe there is additional market opportunity for azenosertib in earlier lines of treatment for ovarian cancer, and across other solid tumor types.

Clinical Development Program

The following ongoing and planned studies constitute the current clinical development program for azenosertib:

•Monotherapy – Phase 2 Clinical Trial in PROC (DENALI - ZN-c3-005).

◦DENALI Part 1b is a single-arm study that evaluated azenosertib monotherapy at our primary dose-of-interest, 400 mg QD 5:2, in 102 patients with PROC. Tissue collection for biomarker assessment was mandated in the study and upon a retrospective analysis, approximately 50% of the patients were Cyclin E1-positive per our IHC cutoff. In January and March of 2025, we announced clinical data from this study, which is described in Part I Item 1, “Business – Clinical Data – DENALI Part 1b” in this Annual Report on Form 10-K.

◦DENALI Part 2 is designed to enroll approximately 100 patients with Cyclin E1-positive PROC at the selected dose who have received one to three prior lines of therapy, or for patients whose tumors are also FRα-high and who have received mirvetuximab soravtansine, one to four prior lines of therapy. We have aligned with the FDA on the design of our DENALI Part 2 study in patients with Cyclin E1-positive PROC, which allows for seamless enrollment across Parts 2a and 2b. DENALI Part 2a is designed to confirm 400 mg QD 5:2 as the recommended pivotal study dose by enrolling approximately 30 patients at each of two dose levels, 400 mg QD 5:2 and 300 mg QD 5:2. DENALI Part 2b is designed to enroll approximately 70 patients at a single dose, the selection of which will be informed by the Part 2a results and FDA interaction.In April 2025, we announced that the first patient was dosed in DENALI Part 2a. In January 2026, we announced that the enrollment for Part 2a was completed in 2025 and we plan to announce dose selection from Part 2a in the first half of 2026. We anticipate a topline readout for DENALI Part 2 by year end 2026. We believe that DENALI Part 2, if successful, has the potential to support an accelerated approval, subject to FDA review. The FDA has granted Fast Track Designation to azenosertib for the treatment of patients with PROC who are positive via IHC for Cyclin E1 protein levels.

•Monotherapy – Phase 3 Clinical Trial in Cyclin E1-positive PROC (ASPENOVA). We have aligned with the FDA on the trial design for ASPENOVA, a randomized Phase 3 confirmatory clinical trial of azenosertib versus standard-of-care chemotherapy for the treatment of patients with Cyclin E1-positive PROC designed to support a full approval of azenosertib in this setting. We plan to initiate ASPENOVA in the first half of 2026 and enroll concurrently with DENALI Part 2b.

•Combination – Phase 1b Clinical Trial of Azenosertib and Chemotherapy or Bevacizumab in Ovarian Cancer (MUIR - ZN-c3-002). We are currently enrolling patients in an arm of our ZN-c3-002 Phase 1b clinical trial that is evaluating azenosertib in combination with bevacizumab as maintenance therapy in ovarian cancer. The dose expansion portion will enroll second-line platinum-sensitive ovarian cancer (PSOC) patients for maintenance treatment, whose disease progressed while on a PARP inhibitor.

We also completed enrollment in a Phase 2 clinical trial evaluating azenosertib as a monotherapy in patients with uterine serous carcinoma, or USC (TETON - ZN-c3-004). We plan to publish results from this trial in the future. We do not plan further development of azenosertib in USC.

Liquidity Overview

Since our inception, our operations have been limited to organizing and staffing our company, business planning, raising capital, establishing our intellectual property portfolio and performing research and development of our product pipeline. We do not have any products approved for commercial sale and have not generated any revenues from product sales. We will not generate revenue from product sales unless and until we successfully complete clinical development, obtain regulatory approval for, and commercialize one or more of our product candidates. We will need to raise substantial additional capital to support our continuing operations and pursue our growth strategy.

Since inception, we have incurred significant operating losses. Our net losses were $137.1 million for the year ended December 31, 2025. We had an accumulated deficit of $1.2 billion as of December 31, 2025. We expect to continue to incur significant expenses and operating losses for the foreseeable future. We had cash, cash equivalents and marketable securities of $245.9 million as of December 31, 2025. We believe that our existing cash, cash equivalents and marketable securities as of December 31, 2025 will be sufficient to fund our operating expenses and capital expenditure requirements into late 2027. We have based these estimates on assumptions that may prove to be imprecise, and we could utilize our available capital resources sooner than we expect.

License Agreements and Strategic Collaborations

Recurium IP Holdings, LLC License Agreement

In December 2014, our wholly owned subsidiary, Zeno Pharmaceuticals, Inc., entered into the Recurium Agreement with Recurium IP Holdings, LLC, or Recurium IP, which was subsequently amended, under which Zeno Pharmaceuticals, Inc. was granted an exclusive worldwide license to certain intellectual property rights owned or controlled by Recurium IP to develop and commercialize pharmaceutical products for the treatment or prevention of disease, other than for providing pain relief. Following a corporate restructuring disclosed elsewhere in this Annual Report on Form 10-K, our wholly owned subsidiary, ZMI, became the Zentalis contracting party to the Recurium Agreement. The intellectual property rights exclusively licensed by ZMI under the Recurium Agreement include certain intellectual property covering azenosertib. ZMI has the right to sublicense its rights under the Recurium Agreement, subject to certain conditions. ZMI is required to use commercially reasonable efforts to develop and commercialize at least one product that comprises or contains a compound modulating one of ten specific biological targets and to execute certain development activities.

Under the terms of the Recurium Agreement, ZMI is obligated to make development and regulatory milestone payments, pay royalties on net sales, and make certain sublicensing payments with respect to products that comprise or contain a compound modulating one of ten specific biological targets, including azenosertib. ZMI is obligated to make development and regulatory milestone payments for each such licensed product of up to $44.5 million. In addition, ZMI is obligated to make milestone payments of up to $150,000 for certain licensed products used in animals. ZMI is also obligated to pay royalties on sales of such licensed products at a mid- to high-single digit percentage. In addition, if ZMI chooses to sublicense or assign to any third parties its rights under certain patents exclusively in-licensed under the Recurium Agreement, ZMI must pay to Recurium IP 20% of certain sublicensing income received in connection with such transaction.

The Recurium Agreement will expire on the later of December 21, 2032 and, on a country-by-country basis, on the date of expiration of the last-to-expire royalty term for all licensed products in such country, unless earlier terminated by either party for cause or a bankruptcy event.

Pfizer Development Agreement

In April 2022, we entered into a development agreement with Pfizer to collaborate to advance the clinical development of azenosertib. We did not grant Pfizer any economic ownership or control of azenosertib or the rest of our pipeline. In October 2022, we announced our first clinical development collaboration with Pfizer to initiate a Phase 1/2 dose escalation study of azenosertib, in combination with encorafenib and cetuximab (an FDA-approved standard of care known as the BEACON regimen) in patients with BRAF V600E-mutant mCRC. In January 2025, we announced that we would not advance to the dose expansion phase of the study due to resource prioritization and an evolving treatment landscape.

GSK Clinical Trial Collaboration and Supply Agreement

In April 2021, we entered into a clinical trial collaboration and supply agreement with GSK under which we have evaluated the combination of azenosertib and niraparib, GSK’s poly (ADP-ribose) polymerase (PARP) inhibitor, in patients

with PROC. In January 2025, we announced that the trial was fully enrolled and that we were not proceeding further with the development of the combination of azenosertib with niraparib as efficacious exposures of azenosertib were not reached. Pursuant to this agreement, we were responsible for the conduct and cost of the study, under the supervision of a joint development committee made up of our representatives and representatives of GSK. GSK supplied niraparib for use in the collaboration, at no cost to us.

This agreement does not grant any right of first negotiation to participate in future clinical trials, and neither party granted the other any additional right or ability to evaluate their respective compounds in any other clinical studies, either as monotherapy or in combination with any other product or compound, in any therapeutic area.

The agreement with GSK will expire upon completion of all obligations of the parties thereunder or upon termination by either party. In addition, there are standard early termination provisions under this agreement.

Immunome Agreements

In January 2024, we entered into an exclusive, worldwide license agreement with Immunome, or the Immunome License Agreement, under which Immunome licensed from us ZPC-21 (now known as IM-1021), a preclinical ROR1 ADC with best-in-class potential, and our proprietary ADC platform technology, or the ADC Assets. Under the terms of the deal, we received an up-front payment of $35.0 million in cash and Immunome common stock (with the stock valued at the trailing 30-day volume-weighted average price). In October 2024, we entered into an asset purchase agreement with Immunome, pursuant to which Immunome purchased the ADC Assets, or the Immunome Purchase Agreement. We received $25.0 million worth of Immunome common stock, with the shares valued at the trailing 30-day volume-weighted average price of Immunome's common stock. On the date of execution of the transaction, the Immunome stock was valued at $21.9 million based on the closing price of Immunome's common stock on that date. We were also eligible to receive $5.0 million of contingent consideration upon the achievement of a developmental milestone, which was achieved in December 2024. The Immunome License Agreement terminated upon the parties’ entry into the Immunome Purchase Agreement.

Components of Our Results of Operations

Revenue

To date, we have not generated any revenue, and we do not expect to generate any revenue in the foreseeable future from product sales. We have generated, and may in the future generate, revenue from payments received under our licensing, collaboration and asset sale agreements, which included payments of upfront fees, license fees, milestone-based payments and reimbursements for research and development efforts.

Research and Development Expenses

Research and development expenses consist primarily of costs incurred for our research activities, including our discovery efforts, and the development of our product candidates, and include:

•salaries, benefits and other related costs, including non-cash stock-based compensation expense, for personnel engaged in research and development functions;

•expenses incurred under agreements with third parties, including CROs and other third parties that conduct research, preclinical activities and clinical trials on our behalf as well as CMOs that manufacture drug material for use in our preclinical studies and clinical trials;

•costs of outside consultants, including their fees, non-cash stock-based compensation and related travel expenses;

•the costs of laboratory supplies and acquiring, developing and manufacturing preclinical study and clinical trial materials;

•license payments made for intellectual property used in research and development activities; and

•allocated expenses for rent and maintenance of facilities and other operating costs.

We expense research and development costs as incurred. Reimbursed research and development costs under certain collaborative arrangements are recorded as a reduction to research and development expenses and are recognized in the period in which the related costs are incurred.

We track external development costs by product candidate or development program, but we do not allocate personnel costs, general license payments made under our licensing arrangements or other internal costs to specific development programs or product candidates. These costs are included in unallocated research and development expenses and discontinued programs in the table below.

The following table summarizes our research and development expenses by product candidate or development program:

Year Ended December 31,

(in thousands)

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. Following the strategic restructuring announced in January 2025, we incurred certain associated non-recurring expenses in the first quarter of 2025. As a result of the strategic restructuring, we realized a decrease in research and development expenses during the year ended December 31, 2025. If our azenosertib development program continues to advance successfully, we expect our research and development expenses to increase as we initiate and execute our planned Phase 3 ASPENOVA confirmatory study and prepare for potential commercialization.

The successful development of azenosertib, and any of our future product candidates is highly uncertain. At this time, we cannot determine with certainty the duration and costs of our existing and future clinical trials of azenosertib or any other product candidate we may develop or if, when, or to what extent we will generate revenue from the commercialization and sale of any product candidate for which we obtain marketing approval. We may never succeed in obtaining marketing approval for azenosertib, or any future product candidate. The duration, costs and timing of clinical trials and development of our product candidates and any other product candidate we may develop in the future will depend on a variety of factors, including:

•per patient trial costs;

•the number of patients who enroll in each trial;

•the number of trials required for approval;

•the number of sites included in the trials;

•the countries in which the trials are conducted;

•the length of time required to enroll eligible patients;

•the drop-out or discontinuation rates of patients;

•any delays in clinical trials, including as a result of clinical holds or the global macroeconomic environment;

•potential additional safety monitoring requested by regulatory agencies;

•the duration of patient participation in the trials and follow-up;

•the phase of development of the product candidate;

•the efficacy and safety profile of the product candidate.

•uncertainties in clinical trial design and patient enrollment rates;

•the actual probability of success for our product candidates, including the safety and efficacy, early clinical data, competition, manufacturing capability and commercial viability;

•significant and changing government regulation and regulatory guidance;

•the timing and receipt of any marketing approvals;

•the expense of filing, prosecuting, defending and enforcing any patent claims and other intellectual property rights; and

•our ability to attract and retain skilled personnel.

A change in the outcome of any of these variables with respect to the development of a product candidate could mean a significant change in the costs and timing associated with the development of that product candidate. For example, if the FDA or another regulatory authority were to require us to conduct clinical trials beyond those that we anticipate will be required for the completion of clinical development of a product candidate, or if we experience significant delays in our clinical trials due to patient enrollment or other reasons, we would be required to expend significant additional financial resources and time on the completion of clinical development.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and other related costs, including non-cash stock-based compensation, for personnel in our executive, finance, business development and administrative functions. General and administrative expenses also include legal fees relating to intellectual property and corporate matters; professional fees for accounting, auditing, tax and consulting services; insurance costs; travel expenses; and facility-related expenses, which include direct depreciation costs and allocated expenses for rent and maintenance of facilities and other operating costs.

Following the strategic restructuring announced in January 2025 for which we incurred certain associated non-recurring expenses in the first quarter of 2025, we have realized a decrease in general and administrative expenses during the year ended December 31, 2025; however, if our azenosertib development program continues to advance successfully, we expect our general and administrative expenses to increase as we initiate and execute our planned Phase 3 ASPENOVA confirmatory study and prepare for potential commercialization. We also expect to continue to incur expenses associated with being a public company, including costs of accounting, audit, legal, regulatory and tax-related services associated with maintaining compliance with Nasdaq and SEC requirements; director and officer insurance costs; and investor and public relations costs.

Restructuring Expenses

Restructuring expenses consist of involuntary employee termination benefits pursuant to a one-time benefit arrangement.

Investment and Other Income, Net

Investment and other income, net consists of interest earned on cash, cash equivalents and available-for-sale marketable securities, sublease income and the change in value of equity securities during the period.

Income Taxes

Since our inception, we and our corporate subsidiaries have generated cumulative federal, state and foreign net operating loss in certain jurisdictions for which we have not recorded any net tax benefit due to uncertainty around utilizing these tax attributes within their respective carryforward periods.

Results of Operations

Comparison of Years Ended December 31, 2025 and 2024

The following table summarizes our results of operations for the years ended December 31, 2025 and 2024, together with the changes in those items in dollars:

Year Ended December 31,

(in thousands)

Operating Expenses

Net loss attributable to noncontrolling interests — (28) 28

Revenues from Licensing and Sales of Intellectual Property

Revenues from licensing and sales of intellectual property for the year ended December 31, 2025 were zero compared to $67.4 million for the year ended December 31, 2024. The decrease relates to the Immunome License Agreement and related stock issuance agreement with Immunome entered during the three months ended March 31, 2024 and the Immunome Purchase Agreement and the related stock issuance agreement with Immunome entered during the three months ended December 31, 2024.

Research and Development Expenses

Research and development, or R&D, expenses for the year ended December 31, 2025 were $107.3 million, compared to $167.8 million for the year ended December 31, 2024. The decrease of $60.5 million was primarily due to decreases of $22.3 million for clinical expenses, $12.9 million for lab services, $8.8 million for drug manufacturing, and $1.3 million for supplies and other expense. A decrease of $16.4 million from personnel expense, of which $6.5 million was non-cash stock-based compensation, also contributed to the overall reduction in research and development expenses. These decreases were partially offset by an increase of $1.2 million from a one-time impairment charge recorded on research and development equipment during the first quarter ended March 31, 2025.

Restructuring Expenses

On January 22, 2025, our Board of Directors approved a strategic restructuring of the Company to support execution of late-stage development for azenosertib, and extend its cash runway beyond a potentially registration-enabling azenosertib topline readout from the Company’s DENALI Part 2 study, anticipated by the end of 2026. In connection with this strategic restructuring, the Company reduced its workforce by approximately 40%. Restructuring expenses for the year ended December 31, 2025 were $7.8 million, compared to zero during the year ended December 31, 2024.

General and Administrative Expenses

General and administrative expenses for the year ended December 31, 2025 were $37.7 million, compared to $87.1 million during the year ended December 31, 2024. The decrease of $49.4 million was primarily due to a decrease of $47.1 million of personnel expense, of which $40.8 million was non-cash stock-based compensation. Decreases of $3.3 million related to consulting and outside services also contributed to the overall reduction in general and administrative expenses. These decreases were partially offset by an increase of $1.0 million related to allocated and other costs.

Goodwill Impairment

Goodwill impairment for 2024 of $3.7 million was the result of an impairment test performed in the fourth quarter of 2024.

Investment and Other Income, Net

Investment and other income, net was $16.2 million for the year ended December 31, 2025, compared to $25.5 million for the year ended December 31, 2024. The decrease of $9.3 million was primarily driven by a decrease of $8.4 million in returns on invested cash and marketable debt securities and decreases in the mark to market adjustment for the fair value of Immunome common stock of $4.1 million. The decreases were partially offset by a reduction of one-time miscellaneous expenses incurred in 2024.

Liquidity and Capital Resources

As a result, we will need to raise substantial additional capital to support our continuing operations and pursue our strategy. Until such time as we can generate significant revenue from product sales, if ever, we plan to finance our operations through the sale of equity, debt financings or other capital sources, which may include collaborations with other companies or other strategic transactions. There are no assurances that we will be successful in obtaining an adequate level of financing as and when needed to finance our operations on terms acceptable to us or at all, particularly in light of the global macroeconomic environment and fluctuating inflation and interest rates. If we are unable to secure adequate additional funding as and when needed, we may have to significantly delay, scale back or discontinue the development and commercialization of azenosertib or delay our pursuit of potential in-licenses or acquisitions.

Because of the numerous risks and uncertainties associated with developing and commercializing therapeutics, we are unable to predict the timing or amount of increased expenses or when or if we will be able to achieve or maintain profitability. Even if we are able to generate revenue from product sales, we may not become profitable. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce or terminate our operations.

We do not currently have any approved products and have never generated any revenue from product sales. To date, we have financed our operations primarily through the sale of equity securities. From inception through December 31, 2025, we raised a total of $1.2 billion in gross proceeds from the sale of shares of our common stock and convertible preferred units. As of December 31, 2025, we had $36.0 million in cash and cash equivalents, $209.9 million in marketable debt securities, and an accumulated deficit of $1.2 billion. We maintain the majority of our cash and cash equivalents in accounts with major financial institutions, and our deposits at these institutions exceed insured limits. Market conditions can impact the viability of these institutions. In the event of failure of any of the financial institutions where we maintain our cash and cash equivalents, there can be no assurance that we would be able to access uninsured funds in a timely manner or at all. Any inability to access or delay in accessing these funds could adversely affect our business and financial position. We had no indebtedness as of December 31, 2025.

ATM Program

In May 2021, the Company entered into a sales agreement, or the Sales Agreement, with SVB Leerink LLC, or SVB Leerink, as sales agent (the "Sales Agreement"), pursuant to which the Company may, from time to time, issue and sell common stock with an aggregate value of up to $75.0 million in “at-the-market” offerings, or the ATM, under the Company's Registration Statement on Form S-3 (File No. 333-286122) filed with the SEC on March 26, 2025. Sales of common stock pursuant to the Sales Agreement, may be made in sales deemed to be an “at the market offering” as defined in Rule 415(a) of the Securities Act, including sales made directly through the Nasdaq Global Market or any other existing trading market for the Company's common stock. In December 2025, the Company sold 3,928,571 shares of common stock under the Sales Agreement at a price of $1.40 per share, raising aggregate gross proceeds of $5.5 million before fees and expenses of $0.1 million. As of December 31, 2025 there was $69.5 million of our common stock remaining available for sale under our ATM.

Stock Purchase Agreement

On December 15, 2025, the Company entered into a Stock Purchase Agreement (the “Stock Purchase Agreement”) with Matrix Capital Master Fund, LP ("Matrix"), one of our then-stockholders. Pursuant to the Stock Purchase Agreement, the

Company agreed to repurchase 7,500,000 shares of the Company’s common stock from Matrix at a price of $1.33 per share, representing a discount from the Company’s closing share price of $1.40 on December 12, 2025 (the “Repurchase”). The Repurchase closed on December 15, 2025.

Cash Flows

The following table summarizes our sources and uses of cash for the period presented:

Year Ended December 31,

(in thousands)

Net cash used in operating activities $ (125,247) $ (170,860)

Net cash (used in) provided by financing activities (4,282) 108

Net increase in cash, cash equivalents and restricted cash $ 2,094 $ 5,809

Operating Activities

We have incurred losses since inception. Net cash used in operating activities for the year ended December 31, 2025 was $125.2 million, consisting primarily of our net loss of $137.1 million as we incurred expenses associated with the restructuring event, research activities for our product candidate and incurred general and administrative expenses, as well as changes in operating assets and liabilities of $9.1 million, partially offset by non-cash adjustments of $20.9 million.

Net cash used in operating activities for the year ended December 31, 2024 was $170.9 million, consisting primarily of our net loss of $165.9 million as we incurred expenses associated with research activities for our lead product candidates and incurred general and administrative expenses, as well as changes in operating assets and liabilities of $16.5 million, partially offset by non-cash adjustments of $11.5 million.

Investing Activities

Net cash provided by investing activities for the year ended December 31, 2025 of $131.6 million was attributable to proceeds from maturities of $250.0 million of marketable debt securities, the sale of marketable equity securities of $20.4 million and proceeds from the sale of property and equipment of $698 thousand offset by net investment of excess cash of $139.5 million.

Net cash provided by investing activities for the year ended December 31, 2024 of $176.6 million was attributable to proceeds from maturities of $271.2 million of marketable debt securities, the sale of marketable equity securities of $33.5 million and proceeds from the sale of property and equipment of $65 thousand offset by net investment of excess cash of $128.0 million and the purchases of property and equipment of $221 thousand.

Financing Activities

Net cash used in financing activities for the year ended December 31, 2025 of $4.3 million was attributable to the Repurchase of $10.0 million offset by the $5.4 million net cash provided by shares sold through the SVB Leerink ATM agreement, and an additional $304 thousand provided from the issuance of common stock under equity incentive plans.

Net cash provided by financing activities in the year ended December 31, 2024 of $108 thousand consisted of $349 thousand provided from the issuance of common stock under equity incentive plans, offset by cash used in the net-settlement of restricted stock unit vesting of $241 thousand.

Funding Requirements

Our future capital requirements will depend on many factors, including:

•the clinical development of azenosertib for the treatment of oncology indications;

•the preclinical and clinical development of other programs, resources allowing;

•the development of a companion diagnostic with a partner in conjunction with our clinical development of azenosertib as a monotherapy for the treatment of Cyclin E1-positive PROC, if applicable, diagnostics tools for additional biomarkers for azenosertib and any future product candidates;

•the costs of in-licensing or acquiring the rights to other products, product candidates or technologies;

•the legal costs related to maintaining, expanding and protecting our intellectual property portfolio;

•hiring additional personnel, if needed;

•the costs to seek regulatory approval for azenosertib for the treatment of Cyclin E1-positive PROC and support our diagnostic partner's seeking regulatory approval of a companion diagnostic to identify patients with Cyclin E1-positive PROC, and resources allowing, seek regulatory approval of azenosertib for additional oncology indications, assuming supportive clinical data; and

•the costs to seek regulatory approval for any future product candidates and, if needed, diagnostics tools for biomarkers associated with such product candidates, that successfully complete clinical development, resources allowing.

As of December 31, 2025, we have $3.9 million and $35.7 million in current and long-term lease liabilities, respectively. We believe that our existing cash, cash equivalents and marketable securities as of December 31, 2025 will be sufficient to fund our operating expenses and capital expenditure requirements into late 2027. We have based these estimates on assumptions that may prove to be imprecise, and we could utilize our available capital resources sooner than we expect.

Because of the numerous risks and uncertainties associated with research, development and commercialization of pharmaceutical drugs, it is difficult to estimate with certainty the amount of our working capital requirements. Our future funding requirements will depend on many factors, including:

•the progress, costs and results of our clinical trials for azenosertib for patients with Cyclin E1-positive PROC and, resources allowing, any additional indications, and any future product candidates;

•the progress, costs and results to develop a companion diagnostic to identify patients with Cyclin E1-positive PROC;

•the progress, costs and results of additional research and preclinical studies in other research programs we initiate in the future and, if needed, of diagnostics tools for additional biomarkers for azenosertib and any future product candidates;

•the costs and timing of process development and manufacturing scale-up activities associated with azenosertib and, resources allowing, our product candidates and other programs as we advance them through preclinical and clinical development;

•our ability to establish and maintain strategic collaborations, licensing or other agreements and the financial terms of such agreements;

•the extent to which we in-license or acquire rights to other products, product candidates or technologies;

•the costs and timing of preparing, filing and prosecuting patent applications, maintaining and protecting our intellectual property rights and defending against any intellectual property-related claims; and

•our ability to attract and retain skilled personnel.

Further, our operating results may change in the future, and we may need additional funds to meet operational needs and capital requirements associated with such operating plans.

Until such time as we can generate significant revenue from product sales, if ever, we plan to finance our operations through the sale of equity, debt financings, or other capital sources, which may include collaborations with other companies or other strategic transactions.

We currently have no credit facility or committed sources of capital. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect your rights as a common stockholder. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through other third-party funding, collaboration agreements, strategic alliances, licensing arrangements or marketing and distribution arrangements, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market products or product candidates that we would otherwise prefer to develop and market ourselves.

Critical Accounting Estimates

Our management’s discussion and analysis of financial condition and results of operations is based on our financial statements, which have been prepared in accordance with generally accepted accounting principles in the United States. The preparation of our financial statements and related disclosures require us to make estimates and assumptions that affect the reported amounts of assets and liabilities, costs and expenses and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions.

While our significant accounting policies are described in more detail in the notes to our audited consolidated financial statements included elsewhere in this Annual Report on Form 10-K, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our financial statements.

Impairment of Long-Lived Assets

Revenue Recognition

Research and Development Expenses - Clinical Trial Accruals

Share-Based Payments

Recent Accounting Pronouncements

See Note 2 to our audited consolidated financial statements included elsewhere in this Annual Report on Form 10-K for further information on certain accounting standards that have been adopted during 2025 or that have not yet been required to be implemented and may be applicable to our future operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are a smaller reporting company, as defined in Rule 12b-2 under the Securities Exchange Act of 1934, as amended, for this reporting period and are not required to provide the information required under this item.

Item 8. Financial Statements and Supplementary Data.

The financial statements required to be filed pursuant to this Item 8 are appended to this report. An index of those financial statements is found in Item 15 of Part IV of this Annual Report on Form 10-K.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

None.

Item 9A. Controls and Procedures.

Inherent Limitations on Effectiveness of Controls and Procedures

In designing and evaluating our disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our principal executive officer and principal financial officer, evaluated, as of the end of the period covered by this Annual Report on Form 10-K, the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act). Based on that evaluation, our principal executive officer and principal financial officer concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of December 31, 2025.

Management’s Annual Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f). Under the supervision and with the participation of our management, including our principal executive officer and our principal financial officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting based on the framework in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on the evaluation under this framework, our principal executive officer and our principal financial officer have concluded that our internal control over financial reporting was effective as of December 31, 2025.

Attestation Report of the Registered Public Accounting Firm

In accordance with applicable rules and regulations, this report does not include an attestation report of our independent registered public accounting firm regarding internal control over financial reporting.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) identified in management’s evaluation pursuant to Rules 13a-15(d) or 15d-15(d) of the Exchange Act that occurred during the quarter ended December 31, 2025 that materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information.

Insider Trading Arrangements and Policies

During the three months ended December 31, 2025, no director or officer of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

Not applicable.

Part III

Item 10. Directors, Executive Officers and Corporate Governance.

The information required by this item will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders under the sections entitled "Proposal 1: Election of Directors," "Executive Officers," "Corporate Governance" and if required, "Delinquent Section 16(a) Reports" and is incorporated herein by reference.

Item 11. Executive Compensation.

The information required by this item will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders under the sections entitled "Executive Compensation," "Director Compensation" and "Corporate Governance" and is incorporated herein by reference.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

The information required by this item will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders under the sections entitled "Securities Authorized For Issuance Under Equity Compensation Plans" and "Security Ownership of Certain Beneficial Owners and Management" and is incorporated herein by reference.

Item 13. Certain Relationships and Related Transactions, and Director Independence.

The information required by this item will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders under the sections entitled "Certain Relationships and Related Person Transactions" and "Corporate Governance" and is incorporated herein by reference.

Item 14. Principal Accountant Fees and Services.

The information required by this item will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders under the sections entitled "Proposal 2: Ratification of Appointment of Independent Registered Public Accounting Firm" and "Independent Registered Public Accounting Firm Fees and Other Matters" and is incorporated herein by reference.

Part IV

Item 15. Exhibits and Financial Statement Schedules.

(a)(1) Financial Statements.

The following documents are included on pages F-1 through F-31 attached hereto and are filed as part of this Annual Report on Form 10-K.

Index to Consolidated Financial Statements

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID: 42) F-1

Consolidated Financial Statements

Consolidated Balance Sheets F-3

Consolidated Statements of Operations F-4

Consolidated Statements of Comprehensive Loss F-5

Consolidated Statements of Stockholders' Equity F-6

Consolidated Statements of Cash Flows F-8

Notes to Consolidated Financial Statements F-10

(a)(2) Financial Statement Schedules.

All financial statement schedules have been omitted because they are not applicable, not required or the information required is shown in the financial statements or the notes thereto.

(a)(3) Exhibits.

The following is a list of exhibits filed as part of this Annual Report on Form 10-K.

ExhibitNumber Description Incorporated by Reference

Form File No. Exhibit Filing Date Filed/Furnished Herewith

ExhibitNumber Description Incorporated by Reference

23.1 Consent of Independent Registered Public Accounting Firm. *

ExhibitNumber Description Incorporated by Reference

101.SCH Inline XBRL Taxonomy Extension Schema Document *

101.CAL Inline XBRL Taxonomy Extension Calculation Linkbase Document *

101.DEF Inline XBRL Taxonomy Extension Definition Linkbase Document *

101.LAB Inline XBRL Taxonomy Extension Label Linkbase Document *

101.PRE Inline XBRL Taxonomy Extension Presentation Linkbase Document *

* Filed herewith.

** Furnished herewith.

# Indicates management contract or compensatory plan.

† Portions of this exhibit (indicated by asterisks) have been redacted in compliance with Regulation S-K Item 601(b)(10)(iv).

Item 16. Form 10-K Summary.

None.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

ZENTALIS PHARMACEUTICALS, INC.

Date: March 26, 2026 By: /s/ Julie Eastland

Julie Eastland

President and Chief Executive Officer

Pursuant to the requirements of the Securities Exchange Act of 1934, this Report has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated.

Name Title Date

Julie Eastland

Vincent A. Vultaggio

/s/ Scott Myers Chairperson of the Board of Directors March 26, 2026

Scott Myers

/s/ David Johnson Director March 26, 2026

David Johnson

/s/ Enoch Kariuki Director March 26, 2026

Enoch Kariuki

/s/ Jan Skvarka Director March 26, 2026

Jan Skvarka

/s/Luke Walker, M.D. Director March 26, 2026

Luke Walker, M.D.

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of Zentalis Pharmaceuticals, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Zentalis Pharmaceuticals, Inc. (the Company) as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive loss, stockholders’ equity and cash flows for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Accrued clinical trial expenses

F-1

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 2019.

San Diego, California

March 26, 2026

F-2

Zentalis Pharmaceuticals, Inc.

Consolidated Balance Sheets

(In thousands, except share amounts and par value)

December 31,

ASSETS

Current assets

Marketable debt securities, available for sale 209,898 318,009

Marketable equity securities — 19,174

Contracts receivable — 5,000

Prepaid expenses and other current assets 7,298 9,982

Prepaid expenses and other assets 4,108 4,417

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities

Other long-term liabilities 500 849

Commitments and contingencies (see Note 10)

EQUITY

Accumulated other comprehensive income 196 558

Total liabilities and stockholders' equity $ 288,967 $ 430,337

See accompanying notes to consolidated financial statements.

F-3

Zentalis Pharmaceuticals, Inc.

Consolidated Statements of Operations

(In thousands, except per share amounts)

Year endedDecember 31,

Revenues from Licensing and Sales of Intellectual Property $ — $ 67,425 $ —

Operating Expenses

Zentera in-process research and development — — 45,568

Restructuring 7,796 — —

Goodwill impairment — 3,736 —

Other Income (Expense)

Loss on equity method investment — — 16,014

Net loss attributable to noncontrolling interests — (28) (114)

See accompanying notes to consolidated financial statements.

F-4

Zentalis Pharmaceuticals, Inc.

Consolidated Statements of Comprehensive Loss

(In thousands)

Year endedDecember 31,

Other comprehensive income (loss):

Unrealized gain (loss) on marketable debt securities, net (362) (1,636) 3,547

Comprehensive loss attributable to noncontrolling interests — (28) (114)

See accompanying notes to consolidated financial statements.

F-5

Zentalis Pharmaceuticals, Inc.

Consolidated Statements of Stockholders' Equity

(In thousands, except per unit amounts)

Zentalis Stockholders

Shares Amount

Share-based compensation expense — — 54,822 — — — 54,822

Issuance of common stock upon exercise of options 54 — 995 — — — 995

Shares issued under employee stock purchase plan 42 — 628 — — — 628

Cancellation of restricted stock awards (3) — — — — — —

Other comprehensive income — — — 3,547 — — 3,547

Net loss attributable to non-controlling interest — — — — — (114) (114)

Net loss attributable to Zentalis — — — — (292,191) — (292,191)

F-6

Zentalis Stockholders

Shares Amount

Share-based compensation expense — — 67,269 — — — 67,269

Deconsolidation of Kalyra — — — — — (79) (79)

Issuance of common stock upon exercise of options 1 — 8 — — — 8

Shares issued under employee stock purchase plan 48 — 340 — — — 340

Other comprehensive loss — — — (1,636) — — (1,636)

Net loss attributable to non-controlling interest — — — — — (28) (28)

Net loss attributable to Zentalis — — — — (165,839) — (165,839)

Zentalis Stockholders

Shares Amount

Share-based compensation expense — — 20,722 — — 20,722

Other comprehensive loss — — — (362) — (362)

Shares issued under employee stock purchase plan 237 — 304 — — 304

Net loss attributable to Zentalis — — — — (137,060) (137,060)

See accompanying notes to consolidated financial statements.

F-7

Zentalis Pharmaceuticals, Inc.

Consolidated Statements of Cash Flows

(in thousands)

Year Ended December 31,

Operating activities:

Adjustments to reconcile net loss to net cash used in operating activities:

Operating lease right-of-use and fixed asset impairment 4,136 — 4,953

Goodwill impairment — 3,736 —

(Gain)/loss on disposal of equipment (660) (13) 406

Non-cash recognized mark-to-market of equity securities (1,239) (5,228) —

Accretion of discounts on marketable securities, net (2,763) (8,002) (13,157)

Loss on equity method investment — — 16,014

Deferred income taxes — — (853)

Deconsolidation of Kalyra — (79) —

Changes in operating assets and liabilities:

Operating lease right-of-use assets and liabilities, net 201 264 623

Investing activities:

Proceeds from sale of marketable equity securities 20,413 33,479 —

Proceeds from sale of property and equipment 698 65 —

Purchases of property and equipment — (221) (583)

Financing activities:

Proceeds from issuance of common stock, net 5,390 — 235,680

Repurchase of common stock (9,976) — —

Net-settlement of restricted stock unit vesting — (241) —

Net cash (used in) provided by financing activities (4,282) 108 237,303

Supplemental disclosure of cash flow information:

Supplemental disclosure of non-cash investing and financing activities:

F-8

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the Consolidated Statements of Cash Flows for the periods presented:

Year Ended December 31,

See accompanying notes to consolidated financial statements.

F-9

Zentalis Pharmaceuticals, Inc.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. Organization and Business

Organization

Zentalis Pharmaceuticals, Inc. (“Zentalis,” “We” or the “Company”) is a clinical-stage biopharmaceutical company developing azenosertib (ZN-c3), an investigational potentially first-in-class and best-in-class WEE1 inhibitor for patients with Cyclin E1-positive platinum-resistant ovarian cancer ("Cyclin E1-positive PROC"). The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. All of the Company’s tangible assets are held in the United States.

Liquidity

Substantial doubt about an entity’s ability to continue as a going concern exists when relevant conditions and events, considered in the aggregate, indicate that it is probable that the entity will be unable to meet its obligations as they become due within one year from the financial statements issuance date. The Company determined that there are no conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date that the audited consolidated financial statements for the year ended December 31, 2025 are issued.

2. Summary of Significant Accounting Policies

Basis of Presentation

The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) and include our wholly-owned subsidiaries and Kalyra Pharmaceuticals, Inc. ("Kalyra"), a variable interest entity (“VIE”) for which we were the primary beneficiary until Kalyra was dissolved in January 2024. All intercompany transactions and balances have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year's presentation.Following the dissolution of Kalyra, we no longer have an interest in any VIEs.

We evaluate our ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether we are the primary beneficiary of the VIE. In determining whether we are the primary beneficiary of a VIE and therefore required to consolidate the VIE, we apply a qualitative approach that determines whether we have both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE.

We will continuously assess whether we are the primary beneficiary of a VIE, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of such VIE. During the periods presented, we have not provided any other material financial or other support to our VIE that we were not contractually required to provide.

Noncontrolling Interests

Noncontrolling interests represent interests held by third parties in our consolidated subsidiaries. We reflect noncontrolling interest attributable to the other owners in a separate line in our consolidated statements of operations and a separate line within stockholders' equity in our consolidated balance sheets.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in our consolidated financial statements and accompanying notes. On an ongoing basis, we evaluate our estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates.

Cash and Cash Equivalents

Cash equivalents are comprised of short-term, highly-liquid investments with maturities of ninety days or less at the date of purchase. As of December 31, 2025 and 2024, our cash equivalents consisted of money market funds.

F-10

Marketable Debt Securities

Marketable debt securities are investments with original maturities of more than ninety days from the date of purchase that we have the ability to liquidate to fund current operations. Accordingly, those investments with contractual maturities of greater than one year from the date of purchase are classified as short-term investments on the accompanying consolidated balance sheets. Marketable debt securities are considered available-for-sale and are carried at fair value with unrealized gains and losses recorded in other comprehensive income (loss) and included as a separate component of stockholders' equity. The cost of marketable debt securities is adjusted for amortization of premiums or accretion of discounts to maturity, and such amortization or accretion is included in investment and other income, net through an allowance account. We use the specific identification method for calculating realized gains and losses on marketable securities sold. Realized gains and losses on marketable securities, if any, are included in investment and other income, net in the consolidated statements of operations.

Investments in Equity Securities

We carry investments of less than twenty percent ownership in equity securities at fair value and record the changes in fair value in the consolidated statement of operations as a component of Investment and other income, net. We account for our equity investments in publicly traded companies at their listed stock price. As of December 31, 2025, we no longer hold any equity investments.

Contracts Receivable

Our contracts receivable balance represents the amounts we are contractually allowed to bill our customers and that are due to us unconditionally for goods we have delivered, services we have performed or milestones achieved. When we bill our customers with payment terms based on the passage of time, we consider the contracts receivable to be unconditional.

Restricted Cash

Under the terms of our office leases, we are required to maintain a letter of credit as a security deposit during the term of such leases. At December 31, 2025 and 2024, restricted cash of $2.6 million was pledged as collateral for the letters of credit.

Fair Value of Financial Instruments

The authoritative guidance defines fair value and requires us to establish a framework for measuring fair value and disclosure about fair value measurements using a three-tier approach. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.

Our financial instruments include cash equivalents, marketable securities, prepaid expenses and other assets, accounts payable and accrued expenses. Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision.

The fair value of marketable securities is determined using proprietary valuation models and analytical tools, which utilize market pricing or prices for similar instruments that are both objective and publicly available, such as matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities and bids and offers.

The carrying amount of cash equivalents, prepaid expenses and other assets, accounts payable and accrued expenses are generally considered to be representative of their respective values because of the short-term nature of those instruments.

Concentrations of Credit Risk and Sources of Supply

We are subject to credit risk from our portfolios of cash equivalents and marketable securities. We maintain our cash and cash equivalent and marketable securities balances with major commercial banks. Deposits held with the financial institutions exceed the amount of insurance provided on such deposits. We are exposed to credit risk in the event of a default by the financial institutions holding our cash and cash equivalents and marketable securities to the extent recorded on the consolidated balance sheets. We have also established guidelines to limit our exposure to credit risk by diversifying our marketable securities portfolio and placing them in investments with maturities that maintain safety and liquidity.

We rely on third-party manufacturers for the supply of raw materials, active drug substance and finished drug product.

F-11

Property and Equipment, Net

Property and equipment are recorded at cost, less accumulated depreciation and amortization. Equipment is depreciated using the straight-line method over its estimated useful life ranging from three to five years and leasehold improvements are amortized using the straight-line method over the estimated useful life of the asset or the lease term, whichever is shorter. Repair and maintenance costs are expensed as incurred.

Leases

We have entered into operating leases for real estate. We determine if an arrangement is a lease at inception and evaluate each lease agreement to determine whether the lease is an operating or finance lease. For leases where we are the lessee, right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent an obligation to make lease payments arising from the lease. Liabilities from operating leases are included in accrued expenses and long-term lease liabilities on our consolidated balance sheet. ROU assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As our leases do not provide an implicit interest rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The operating lease ROU asset also includes any prepaid lease payments, lease incentives received, and costs which will be incurred in exiting a lease. Our leases often include options to extend or terminate the lease. These options are included in the lease term when it is reasonably certain that we will exercise that option. As of December 31, 2025, it is not reasonably certain that these options will be exercised and they are not included within the lease term. Short-term leases with an initial term of 12 months or less are not recorded on the balance sheet. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. We have lease agreements with lease and non-lease components which are accounted for as a single lease component for all of our leases.

Impairment of Long-Lived Assets

We account for long-lived assets in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable. See Note 10 regarding impairment test performed for our operating lease right-of-use asset associated with our San Diego lease.

Goodwill

Our goodwill, which has an indefinite useful life, represents the excess of the cost over the fair value of net assets acquired from its business combination. The determination of the value of goodwill and intangible assets arising from business combinations and asset acquisitions requires extensive use of accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired, including capitalized in-process research and development (“IPR&D”).

Goodwill is reviewed for impairment at least annually, or more frequently if an event occurs indicating the potential for impairment. During the impairment review process, we consider qualitative factors to determine whether it is more-likely-than-not that the fair value of the reporting unit is less than the carrying amount, including goodwill. If we determine that it is not more-likely-than-not that the fair value of our reporting unit is less than the carrying amount, then no additional assessment is deemed necessary. Otherwise, we proceed to compare the estimated fair values of the reporting units with the carrying values, including goodwill. If the carrying amounts of the reporting units exceed the fair values, we record an impairment loss based on the difference.

During the fourth quarter ended December 31, 2024, we concluded the sustained decrease in the Company’s stock price and overall market capitalization during the quarter was an indication that the fair value of a reporting unit might be less than its carrying amount and that a goodwill test was required. As a result, the Company performed a quantitative test over the reporting unit, noting that the fair value of the reporting unit was less than the carrying value, which resulted in an impairment of goodwill of $3.7 million.

In performing a quantitative test for impairment of goodwill, we primarily use the market approach method of valuation that includes the guideline public company method to determine the fair value of the reporting unit. In order to further validate the reasonableness of the fair value concluded for our reporting unit, a reconciliation to market capitalization was performed by estimating a reasonable implied control premium and other market factors.

F-12

Equity Method Accounting

We held significant influence, but not a controlling interest, in our former affiliate Zentera Therapeutics, Inc. ("Zentera"). From the deconsolidation of Zentera during July 2021 until the termination of our collaboration with and divestiture of our ownership position in Zentera during the six-months ended June 30, 2023, this investment was accounted for using the equity method. Our share of earnings or losses of the investment entity were reported on the consolidated statement of operations, with a corresponding increase or decrease to the equity investment carried on the statement of financial position. This information was generally not received sufficiently timely for us to record our portion of earnings or loss in the current financial statements, and therefore we reported our portion of earnings or loss on a one quarter lag. The maximum exposure to loss as a result of our investment in Zentera was directly associated with the carrying amount of the equity method investment on our consolidated balance sheet.

Revenue Recognition and Collaborative Arrangements

The Company generates revenues from payments received under collaborative, intellectual property licensing and sale agreements.

At contract execution, we analyze our collaborative arrangements and license agreements to assess whether both parties are active participants in the activities and are exposed to significant risks and rewards and therefore are within the scope of ASC 808, Collaborative arrangements (“ASC 808”). ASC 808 does not address the recognition and measurement of payments from collaborative arrangements and instead refers companies to use other authoritative accounting literature. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, we first determine which elements of the collaboration reflect a vendor-customer relationship and therefore are within the scope of ASC 606, Revenue from Contracts with Customers. When we determine elements of a collaboration agreement do not reflect a vendor-customer relationship, we consistently apply a reasonable and rational policy election we made by analogizing to authoritative accounting literature. We evaluate the income statement classification for presentation of amounts due from or owed to other participants in a collaboration arrangement based on the nature of each separate activity.

To determine revenue recognition for contracts with customers, we perform the following five steps: (i) identify the contract(s) with the customer; (ii) identify the performance obligations in the contract, including whether they are distinct in the context of the contract; (iii) determine the transaction price, including the constraint on variable consideration; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy the performance obligations.

From time to time we amend our agreements. When this occurs, we are required to assess (1) if the additional goods or services are distinct from the other performance obligations in the previous agreement(s) and (2) if the goods or services are transferred at a stand-alone selling price. If we conclude the goods and/or services in the amendment are distinct from the performance obligations in the original agreement and at a stand-alone selling price, we account for the amendment as a separate agreement. If we conclude the goods and/or services are not distinct and are sold at a stand-alone selling price, we then assess whether the remaining goods or services are distinct from those already provided. If the goods and/or services are distinct from what we have already provided, then we treat the amendment as a termination of the existing contract and allocate the total remaining transaction price from the original agreement and the additional transaction price from the amendment to the remaining goods and/or services. If the goods and/or services are not distinct from what we have already provided, we update the transaction price and allocate it to the remaining performance obligations and adjust revenue previously recognized based on an updated measure of progress for the partially satisfied performance obligations.

Research and Development Expenses

Research and development expenses include salaries and benefits, facilities and other overhead expenses, external clinical trial expenses, research-related manufacturing services, contract services and other outside expenses. Research and development expenses are charged to operating expenses as incurred when these expenditures relate to our research and development efforts and have no alternative future uses.

We are obligated to make upfront payments upon execution of certain research and development agreements. Advance payments, including nonrefundable amounts, for goods or services that will be used or rendered for future research and development activities are deferred. Such amounts are recognized as expense as the related goods are delivered or the related services are performed, or such time when we do not expect the goods to be delivered or services to be performed.

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Clinical Trial Expenses

We make payments in connection with our clinical trials under contracts with CROs that support conducting and managing clinical trials. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis. A portion of our obligation to make payments under these contracts depends on factors such as the successful enrollment or treatment of patients or the completion of other clinical trial milestones.

Expenses related to clinical trials are accrued based on our estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts we are obligated to pay under our clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), we adjust our accruals accordingly. Revisions to our contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain.

Restructuring Expense

The Company recognizes and measures a liability for one-time employee termination benefits for which no future service is required once the plan of termination meets all of the following criteria and has been communicated to employees: (i) management commits to a plan of termination; (ii) the plan identifies the number of employees to be terminated and their job classifications or functions, locations and the expected completion date; (iii) the plan establishes the terms of the benefit arrangement; and (iv) it is unlikely that significant changes to the plan will be made or the plan will be withdrawn. For one-time termination benefits for which future service is required, a liability is measured at the communication date based on its fair value as of the termination date and recognized ratably over the future service period. The Company recognizes and measures a liability for other related costs in the period in which the liability is incurred.

Share-Based Compensation

We record share-based compensation expense associated with equity instruments in accordance with the authoritative guidance for stock-based compensation. The cost of employee services received in exchange for an award of an equity instrument is measured at the grant date based on the estimated fair value of the award and is recognized as expense on a straight-line basis over the requisite service period of the award. Share-based compensation expense for an award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized, and any previously recognized compensation expense is reversed. Forfeitures are recognized as a reduction of share-based compensation expense as they occur.

Income Taxes

Deferred income taxes are recognized for the tax consequences in future years of differences between the tax basis of assets and liabilities and their financial reporting amounts at each year end based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to affect taxable income. A provision has been made for income taxes due on taxable income and for the deferred taxes on temporary differences. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment. Realization of the deferred income tax asset is dependent on gathering sufficient taxable income in future years.

Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. Income tax expense is the combination of the tax payable for the period and the change during the period in deferred tax assets and liabilities. We follow the accounting guidance on accounting for uncertainty in income taxes. The guidance prescribes a recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more-likely-than-not to be sustained upon examination by taxing authorities based on the technical merits of the position.

Accumulated Other Comprehensive Income

Accumulated other comprehensive income is the result of unrealized gains and losses on marketable securities.

Net Loss per Common Share Outstanding

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Basic net loss per common share outstanding is computed by dividing net loss, after adjusting for dividends, if declared, by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share outstanding is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential common shares. Potential common shares consist of unvested restricted stock units and common shares issuable upon the exercise of stock options.

Acquisitions and Contingent Consideration

The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen test to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business.

If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in Accounting Standards Update (ASU) 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquired entity and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations, including contingent assets and liabilities, and non-controlling interest in the acquired entity based on the fair value estimates as of the date of acquisition. In accordance with Accounting Standards Codification (ASC) 805, Business Combinations, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired.

The consideration for the Company’s business acquisitions may include future payments that are contingent upon the occurrence of a particular event or events. The obligations for such contingent consideration payments are recorded at fair value on the acquisition date. The contingent consideration obligations are then evaluated each reporting period. Changes in the fair value of contingent consideration, other than changes due to payments, are recognized as a gain or loss and recorded within change in the fair value of deferred and contingent consideration liabilities in the consolidated statements of comprehensive loss. Contingent consideration liabilities expected to be settled within 12 months after the balance sheet date are presented in current liabilities. Contingent consideration liabilities expected to be settled 12 months after the balance sheet date are presented in long-term liabilities.

If determined to be an asset acquisition, the Company accounts for the transaction under ASC 805-50, which requires the acquiring entity to recognize assets acquired and liabilities assumed based on the cost to the acquiring entity on a relative fair value basis, which includes transaction costs in addition to consideration given. No gain or loss is recognized as of the date of acquisition unless the fair value of non-cash assets given as consideration differs from the assets’ carrying amounts on the acquiring entity’s books. Consideration transferred that is non-cash will be measured based on either the cost (which shall be measured based on the fair value of the consideration given) or the fair value of the assets acquired and liabilities assumed, whichever is more reliably measurable. Goodwill is not recognized in an asset acquisition and any excess consideration transferred over the fair value of the net assets acquired is allocated to the identifiable assets based on relative fair values. If the in-licensed agreement for IPR&D does not meet the definition of a business and the assets have not reached technological feasibility and therefore have no alternative future use, the Company expenses payments made under such license agreements as acquired IPR&D expense in its consolidated statement of comprehensive loss. Contingent consideration payments in asset acquisitions are recognized when the contingency is resolved and the consideration is paid or becomes payable (unless the contingent consideration meets the definition of a derivative, in which case the amount becomes part of the basis in the asset

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acquired). Upon recognition of the contingent consideration payment, the amount is included in the cost of the acquired asset or group of assets.

Adoption and Pending Adoption of Recent Accounting Pronouncements

The following table provides a brief description of recently issued accounting standards, those adopted in the current period and those not yet adopted:

3. Significant Transactions

Immunome License Agreement

In January 2024, the Company and Immunome, Inc. (“Immunome”) entered into an exclusive, worldwide license agreement under which Immunome licensed from Zentalis ZPC-21 (now known as IM-1021), a preclinical ROR1 antibody-drug conjugate (“ADC”) and proprietary ADC technology platform (the “Immunome License Agreement”). Simultaneously, the Company and Immunome entered into a stock issuance agreement (together with the Immunome License Agreement, the “Immunome License Agreements”). The upfront consideration from Immunome amounted to $40.6 million, which consisted of $15.0 million in cash and approximately 2.3 million shares (quantified using a 30-day volume average price) of Immunome common stock valued at approximately $25.6 million on the date of acquisition and accounted for as marketable equity securities on the consolidated balance sheet. Changes to the fair value of the Immunome stock were recorded as a component of investment and other income, net within the condensed consolidated statement of operations. The Company was eligible to receive up to $275.0 million in development, regulatory and sales milestones as well as tiered royalties on net sales of licensed products. The Immunome License Agreement terminated upon the parties’ entry into the Immunome Purchase Agreement in October 2024, as described below under "Immunome Asset Sale", and the Company was no longer eligible to receive development, regulatory and sales milestones or royalties under this Immunome License Agreement. The Company divested the 2.3 million shares of Immunome common stock acquired through the Immunome License Agreement during the year ended December 31, 2024, resulting in net proceeds of $33.5 million.

The Company determined that the Immunome License Agreements fall within the scope of ASC 606, Revenue from Contracts with Customers (ASC 606) as Immunome has contracted to obtain goods and services that are an output of ordinary activities and is a customer. Furthermore, subsequent to the execution of the Immunome License Agreements, the Company is no longer an active participant in the research and is no longer exposed to the significant risks and rewards of the research. Management of the Company determined there was one combined performance obligation for the Immunome License Agreements and know-how given the deliverables are not distinct. The Company evaluated the performance obligation within the Immunome License Agreements and determined the combined performance obligation was satisfied at a point in time with Immunome as the Immunome License Agreements represents a right to use the functional intellectual property as it exists at the time of the Immunome License Agreements, the customer has significant risk and rewards of ownership of the asset and the

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customer has accepted the asset with the transfer of know-how within the quarter ended March 31, 2024. In addition, variable consideration consisting of milestone payments was evaluated based on the Company’s analysis that the possibility of achieving any of the milestone payments was remote, and therefore determined to be constrained and excluded from the transaction price.

Immunome Asset Sale

In October 2024, the Company and Immunome entered into an asset purchase agreement, pursuant to which Immunome purchased from the Company ZPC-21 (now known as IM-1021), a preclinical ROR1 ADC, and the Company’s proprietary ADC platform technology (the “Immunome Purchase Agreement”). The assets subject to the Immunome Asset Sale Agreement were previously licensed to Immunome under the Immunome License Agreement. Simultaneously, the Company and Immunome entered into a stock issuance agreement (together with the Immunome Purchase Agreement, the "Immunome Asset Purchase Agreements"). The upfront consideration from Immunome amounted to $30 million, which consisted of 1.8 million shares of Immunome common stock based on the trailing 30-day volume weighted average price of Immunome common stock (valued at approximately $21.9 million based on the closing price of Immunome's common stock on the date of acquisition), and $5.0 million of contingent consideration due upon the achievement of a developmental milestone. The developmental milestone was achieved in December 2024. Pursuant to the terms of the Immunome Stock Agreement, Zentalis was obligated to hold and not sell greater than 50% of the shares until the six-month anniversary in April 2025 of the closing date, subject to certain exceptions. The Immunome License Agreement terminated upon the parties’ entry into the Immunome Purchase Agreement. The Company divested the 1.8 million shares of Immunome common stock acquired through the Immunome Purchase Agreement during the year ended December 31, 2025, resulting in net proceeds of $20.4 million. As of December 31, 2025, the Company no longer holds shares of Immunome common stock.

The Company determined that the Immunome Asset Purchase Agreements fall within the scope of ASC 606, Revenue from Contracts with Customers (ASC 606) as Immunome has contracted to obtain goods and services that are an output of ordinary activities and is a customer. Furthermore, the Immunome Asset Purchase Agreements changes existing enforceable rights and obligations of the Immunome License Agreement and is accounted for as a contract modification. Management of the Company determined there was one combined performance obligation for the Immunome Asset Purchase Agreements. The Company evaluated the performance obligation within the Immunome Purchase Agreements and determined the performance obligation was satisfied at a point in time with Immunome as the Immunome Asset Purchase Agreements represent the transfer of ownership of functional intellectual property as it existed at the time of the Immunome Asset Purchase Agreements within the quarter ended December 31, 2024. In addition, variable consideration consisting of milestone payments was evaluated based on the Company’s analysis that the possibility of achieving the milestone payment was probable. During the twelve months ended December 31, 2024, the Company recognized revenue from milestone payments of $5.0 million.

4. Segment Reporting and Disaggregation of Relevant Expense Captions

The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The determination of a single business segment is consistent with the consolidated financial information periodically reviewed by the Chief Executive Officer as chief operation decision maker ("CODM") in assessing segment performance and deciding how to allocate resources.

The CODM uses net income or loss to monitor budgets, forecasts and expected cash flows in assessing segment performance and in deciding how to allocate resources. The measure of segment assets is reported on the consolidated balance sheets as total assets.

F-17

The following table presents information about reported significant segment expenses and net loss (in thousands):

Year ended December 31,

Less:

Research and development (1):

Adjustments for cash used in operations:

(1) The Company tracks external development costs by product candidate or development program, but does not allocate personnel costs, general license payments made under our licensing arrangements or other internal costs to specific development programs or product candidates. These costs are included in unallocated research and development expenses and discontinued programs.

(2) Other consists of investment and other income, net, restructuring, goodwill impairment charges, Zentera in-process research and development, Income tax expense (benefit), and loss on equity method investment.

5. Fair Value Measurement

Available-for-sale marketable debt securities consisted of the following (in thousands):

As of December 31, 2025, six of our available-for-sale debt securities with a fair market value of $54.9 million were in a gross unrealized loss position of $11 thousand. Five have been in a gross unrealized loss position of $7 thousand for less than one year, and one has been in a gross unrealized loss position of $4 thousand for more than one year. When evaluating an investment for impairment, we review factors such as the severity of the impairment, changes in underlying credit ratings, forecasted recovery, our intent to sell or the likelihood that we would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. Based on our review of these marketable securities, we believe none of the unrealized loss is as a result of a credit loss as of December 31, 2025,

F-18

because we do not intend to sell these securities, and it is not more-likely-than-not that we will be required to sell these securities before the recovery of their amortized cost basis.

Contractual maturities of available-for-sale debt securities are as follows (in thousands):

Estimated Fair Value

After one but within five years — 68,701

Equity investment gains (losses) for the years ended December 31, 2025 and December 31, 2024 are summarized as follows (in thousands):

Investment gains losses during the year on securities sold 1,239 7,918

Net gains recognized on equity securities $ 1,239 $ 5,228

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Fair value should maximize the use of observable inputs and minimize the use of unobservable inputs. The Company determines the fair value of financial assets and liabilities using three levels of inputs as follows:

Level 1—Inputs which include quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Inputs (other than quoted market prices included in Level 1) that are either directly or indirectly observable, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the instrument’s anticipated life.

Level 3—Unobservable inputs for assets or liabilities and include little or no market activity.

A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

The Company had $0.5 million in contingent consideration liabilities as of December 31, 2025 and 2024 related to the agreement to terminate its Collaboration and License Agreements with Zentera. The contingent consideration balance is limited to one potential milestone payment measured at fair value. The fair value of the contingent consideration is estimated based on the monetary value of the milestone discounted for the probability of achieving the milestone and a present value factor based on the timing of when the milestone is expected to be achieved. The value for the contingent consideration balance is based on significant inputs not observable in the market which represents Level 3 measurement within the fair value hierarchy. This liability existed as of December 31, 2025 and 2024.

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The following table summarizes, by major security type, our cash equivalents and available-for-sale marketable securities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in thousands):

Level 1 Level 2 Level 3 Total estimated fair value

Cash equivalents:

Available-for-sale marketable securities:

Financial liabilities:

Contingent consideration — — 500 500

Total financial liabilities $ — $ — $ 500 $ 500

Level 1 Level 2 Level 3 Total estimated fair value

Cash equivalents:

Available-for-sale marketable securities:

Immunome marketable equity securities 19,174 — $ — 19,174

Financial liabilities:

Contingent consideration — — 500 500

Total financial liabilities $ — $ — $ 500 $ 500

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The following significant unobservable inputs were used in the valuation of the contingent consideration payable to Zentera as variable consideration for a change in control milestone payment of either zero or $15.0 million pursuant to the termination of our Collaboration and License Agreement at December 31, 2025 and December 31, 2024:

(in thousands)

Milestone payment $ 500 Discounted cash flow Likelihood of occurrence 1.0%- 2.4%

Discount rate 40%

Expected term Perpetuity

The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (in thousands):

Contingent consideration at December 31, 2024 $ 500

Changes in the fair value of contingent consideration —

Contingent consideration at December 31, 2025 $ 500

There were no transfers between Level 1 and Level 2 of the fair value hierarchy during the years ended December 31, 2025 and December 31, 2024. We had one instrument that was classified within Level 3 as of December 31, 2025 and December 31, 2024. As of December 31, 2025 and December 31, 2024, no material fair value adjustments were required for non-financial assets and liabilities.

6. Prepaid Expenses and Other Assets

Prepaid expenses and other assets consisted of the following (in thousands):

December 31,

Prepaid software licenses and maintenance 394 509

Foreign R&D credit refund 142 —

Prepaid research and development expenses 6,682 8,788

Total prepaid expenses and other current assets 11,406 14,399

Total prepaid expenses and other assets, current $ 7,298 $ 9,982

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7. Property and Equipment, net

Property and equipment, net consisted of the following (in thousands):

December 31,

Lab equipment $ — $ 3,382

Office equipment and furniture 1,277 1,280

Accumulated depreciation and amortization (2,774) (4,274)

Property and equipment, net $ 2,770 $ 4,699

Depreciation and amortization expense was approximately $0.7 million, $1.3 million and $1.4 million for the years ended December 31, 2025, 2024 and 2023 respectively.

During the year ended December 31, 2025, management determined that changes in circumstances indicated the carrying value of certain research and development equipment may not be recoverable and recorded an impairment charge of $1.2 million, which is reported in the research and development expense line item of the consolidated statement of operations.

8. Accrued Expenses

Accrued expenses consist of the following (in thousands):

December 31,

Accrued research and development expenses $ 14,699 $ 28,715

Accrued general and administrative expenses 466 642

Contingent consideration 500 500

Income taxes payable 194 —

9. Stockholders' Equity

Follow-on Offering of Common Stock

On June 15, 2023, we completed a follow-on offering in which we issued and sold 11,032,656 shares of common stock at a public offering price of $22.66 per share. The total gross proceeds for the offering were approximately $250.0 million, before deducting offering expenses of $14.3 million payable by us.

ATM Offering

In May 2021, the Company entered into a sales agreement, or the Sales Agreement, with SVB Leerink LLC, or SVB Leerink, as sales agent, pursuant to which the Company may, from time to time, issue and sell common stock with an aggregate value of up to $75.0 million in “at-the-market” offerings, or the ATM, under the Company's Registration Statement on Form S-3 (File No. 333-286122) filed with the SEC on March 26, 2025. Sales of common stock pursuant to the Sales Agreement may be made in sales deemed to be an “at the market offering” as defined in Rule 415(a) of the Securities Act, including sales made directly through the Nasdaq Global Market or any other existing trading market for the Company's common stock. In December 2025, the Company sold 3,928,571 shares of common stock under the Sales Agreement at a price of $1.40 per share, raising

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aggregate gross proceeds of $5.5 million before fees and expenses of $0.1 million. As of December 31, 2025 there was $69.5 million of our common stock remaining available for sale under our ATM.

Stock Purchase Agreement

See Note 13 regarding the stock purchase agreement entered into between the Company and Matrix Capital Master Fund, LP (“Matrix”), one of our stockholders during the year ended December 31, 2025.

Share-based Compensation

Effective April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved the 2020 Incentive Award Plan (the "2020 Plan"), which allows for grants to selected employees, consultants and non-employee members of the Board of Directors. We currently grant stock options and restricted stock units (“RSUs”), under the 2020 Plan. Awards may be made under the 2020 Plan covering up to the sum of (1) 5,600,000 shares of common stock; plus (2) any shares forfeited from the unvested restricted shares of our common stock issued upon conversion of unvested Class B common units during the corporate conversion in conjunction with our initial public offering (up to 1,250,000 shares); plus (3) an annual increase on the first day of each fiscal year beginning with the fiscal year ending December 31, 2021 and continuing to, and including, the fiscal year ending December 31, 2030, equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year and (b) such smaller number of shares as determined by our Board of Directors.

In July 2022, the Company’s Board of Directors approved the Zentalis Pharmaceuticals, Inc. 2022 Employment Inducement Incentive Award Plan (the “2022 Inducement Plan”), which is used exclusively for the grant of equity awards to new employees as an inducement material to the employees’ entering into employment with the Company. As of December 31, 2025, the Board of Directors reserved 8,775,000 shares of the Company’s common stock for issuance pursuant to awards granted under the 2022 Inducement Plan.

As of December 31, 2025, 10,687,087 shares were subject to outstanding awards under the 2020 Plan and 6,062,486 shares were available for future grants of share-based awards under the 2020 Plan. As of December 31, 2025, 6,931,460 shares were subject to outstanding awards under the 2022 Inducement Plan and 1,641,290 shares were available for future grants of share-based awards under the 2022 Inducement Plan.

During 2025, we did not issue any shares of common stock in connection with the exercises of stock options for cash. We did not issue any shares of common stock in connection with grants of restricted stock awards ("RSAs"). We issued 1,137,960 shares of common stock, upon vesting of RSU's.

Total share-based compensation expense related to share-based awards was comprised of the following (in thousands):

Year ended December 31,

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Share-based compensation expense by type of share-based award (in thousands):

Year ended December 31,

Total unrecognized estimated compensation cost by type of award and the weighted average requisite service period over which such expense is expected to be recognized (in thousands, unless otherwise noted):

UnrecognizedExpense Remaining Weighted-Average Recognition Period(Years)

Stock Options:The following table summarizes option activity for the year ended December 31, 2025. The amounts include stock options granted to both employees and non-employees:

Exercised — $ —

The weighted average grant date fair value of stock options granted during the years ended December 31, 2025, 2024 and 2023 was $0.94 per share, $4.51 per share and $15.48, respectively. The total intrinsic value of options exercised during the years ended December 31, 2025, 2024 and 2023 was immaterial.

The exercise price of stock options granted is equal to the closing price of the Company's common stock on the date of grant. The fair value of each option award is estimated on the date of grant using the Black-Scholes model. Due to the Company’s limited operating history and a lack of company specific historical and implied volatility data, the Company estimates expected volatility based on the historical volatility of a group of similar companies that are publicly traded. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. The Company uses the “simplified method” for estimating the expected term of employee options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option (generally 10 years). The risk-free interest rate is based on the U.S. Treasury yield for a period consistent with the expected term of the option in effect at the time of the grant. The Company has not issued any dividends and does not expect to issue dividends over the life of the options. As a result, the Company has estimated the dividend yield to be zero. The fair value of the stock options granted during the years ended December 31, 2025, 2024 and 2023 was determined with the following assumptions:

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Year ended December 31,

Average expected term (in years) 6.0 - 6.1 2.7 - 6.1 5.5 - 6.1

Expected dividend yield —% —% —%

Restricted Stock Awards: RSAs are shares of our common stock subject to forfeiture restrictions that lapse based on the awardee's continued employment or service. The shares covered by a RSA cannot be sold, pledged or otherwise disposed of until the awards vest, and any unvested shares will be forfeited following the awardee's termination of service.

There were no RSAs that vested during the year ended December 31, 2025. As of December 31, 2025, there were no RSAs outstanding.

The total grant date fair value of RSAs vested during the years ended December 31, 2024 and 2023 was $4 thousand and $0.7 million, respectively. The fair value of RSAs vested during the years ended December 31, 2024 and 2023 was $14 thousand and $2.7 million, respectively.

Restricted Stock Units: An RSU is a promise by us to issue a share of our common stock upon vesting of the unit.

The following table summarizes RSU activity for the year ended December 31, 2025. The amounts include RSUs granted to both employees and non-employees:

Number of Shares Weighted Average Grant DateFair Value

The estimated fair value of the RSUs was based on the closing market value of our common stock on the date of grant. The total grant date fair value of RSUs vested during the years ended December 31, 2025, 2024 and 2023 was approximately $11.8 million, $11.8 million and $9.7 million, respectively. The fair value of RSUs vested during the years ended December 31, 2025, 2024 and 2023 was approximately $2.0 million, $4.4 million and $7.7 million, respectively.

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Employee Stock Purchase Plan

Effective April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), which was subsequently amended and restated effective March 15, 2021 to provide for a share reserve of 2,000,000 shares. As of December 31, 2025, 1,628,130 shares were available for issuance under the 2020 ESPP.

ZNTL US Equity

ZNTL · 10-K · period ended 2025-12-31

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Item 8. Financial Statements and Supplementary Data.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

Item 9A. Controls and Procedures.

Item 9B. Other Information.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

Item 10. Directors, Executive Officers and Corporate Governance.

Item 11. Executive Compensation.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

Item 13. Certain Relationships and Related Transactions, and Director Independence.

Item 14. Principal Accountant Fees and Services.

Item 15. Exhibits and Financial Statement Schedules.

Item 16. Form 10-K Summary.

ZNTL US Equity☆

ZNTL · 10-K · period ended 2025-12-31

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Item 8. Financial Statements and Supplementary Data.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

Item 9A. Controls and Procedures.

Item 9B. Other Information.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

Item 10. Directors, Executive Officers and Corporate Governance.

Item 11. Executive Compensation.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

Item 13. Certain Relationships and Related Transactions, and Director Independence.

Item 14. Principal Accountant Fees and Services.

Item 15. Exhibits and Financial Statement Schedules.

Item 16. Form 10-K Summary.

ZNTL US Equity