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

Overview

We are a biopharmaceutical company with peptide-based new chemical entities rusfertide and JNJ-2113 (formerly known as PN-235) in different stages of development, all derived from our proprietary discovery technology platform. Our clinical programs fall into two broad categories of diseases; (i) hematology and blood disorders, and (ii) inflammatory and immunomodulatory diseases.

Rusfertide

Our most advanced clinical asset, rusfertide (generic name for PTG-300), is an injectable hepcidin mimetic in development for the potential treatment of erythrocytosis, iron overload and other blood disorders and is wholly owned. Hepcidin is a key hormone in regulating iron equilibrium and is critical to the proper development of red blood cells. Rusfertide mimics the effect of the natural hormone hepcidin, but with greater potency, solubility and stability. Data from our rusfertide Phase 2 clinical trials presented at medical conferences in 2021 and 2022 provided evidence regarding the potential of rusfertide for managing hematocrit, reducing thrombotic risk and improving iron deficiency symptoms. Rusfertide has a unique mechanism of action in the potential treatment of the blood disorder polycythemia vera (“PV”), which may enable it to specifically decrease and maintain hematocrit levels within the range of recommended clinical guidelines without causing the iron deficiency that can occur with frequent phlebotomy. Our rusfertide Phase 2 clinical trials include the following:

At the June 2022 American Society of Clinical Oncology (“ASCO”) Annual Meeting, we presented updated interim results for REVIVE and PACIFIC demonstrating the effects of dosing interruption and resumption. Rusfertide dosing interruption led to loss of effect, including increased phlebotomy rate and increases in hematocrit and red blood cells. Rusfertide restart restored therapeutic benefits. Following the brief clinical hold described below, over 90% of patients in the REVIVE trial provided reconsent and returned to rusfertide treatment after dosing interruption and reinitiation. At the June 2022 European Hematology Association Congress, we presented interim data as of May 2022 showing that rusfertide treatment interruption reverses hematologic gains and re-initiation of treatment restores therapeutic benefits in patients with PV. At the December 2022 American Society of Hematology meeting, we presented data as of October 2022 related to rusfertide, including a subgroup of analyses of the adverse event profile from the REVIVE trial. These preliminary results indicated that 84% of treatment-emergent adverse events (“TEAEs”) were Grade 2 or below. 16% of patients experienced Grade 3 TEAEs and there were no Grade 4 TEAEs.

On March 15, 2023, we announced positive topline results from the blinded, placebo-controlled, randomized withdrawal portion of the REVIVE trial. Subjects receiving rusfertide achieved statistically significant improvements versus placebo in the trial’s primary endpoint.

The double-blind, placebo-controlled, 12-week randomized withdrawal portion was included as Part 2 of the REVIVE trial study to evaluate rusfertide in PV patients with frequent phlebotomy requirements. In the REVIVE trial, subjects were initially enrolled in the 28-week open label dose-titration and efficacy evaluation Part 1 of the study, followed by 1:1 randomization of 53 subjects to placebo versus rusfertide therapy for a subsequent duration of 12 weeks.

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More subjects receiving rusfertide during the blinded randomized withdrawal portion of the REVIVE trial were responders compared with placebo (69.2% versus 18.5%, p=0.0003). A study subject was defined as a responder if the subject completed 12 weeks of double-blind treatment while maintaining hematocrit control without phlebotomy eligibility and without phlebotomy. During the 12 weeks of the blinded randomized withdrawal, only 2 of 26 subjects on rusfertide were phlebotomized.

VERIFY, a global Phase 3 clinical trial of rusfertide in PV for approximately 250 patients, was initiated in the first quarter of 2022. Significant efforts have been taken toward the goal of full enrollment and a high degree of interest has been observed from physicians and patient communities. We expect enrollment completion in the fourth quarter of 2023.

On September 16, 2021, the U.S. Food and Drug Administration (“FDA”) placed a clinical hold on our then ongoing rusfertide clinical trials following our submission to the FDA of findings in a 26-week rasH2 transgenic mouse carcinogenicity study. In October 2021, we submitted a Complete Response to the FDA related to the clinical hold, and the FDA removed the clinical hold on October 8, 2021. In our Complete Response, we provided the individual patient clinical safety reports the FDA requested for human cancers observed in rusfertide clinical trials, updated the investigator brochure and patient informed consent forms for ongoing rusfertide trials, proposed new safety and stopping rules in trial protocols for our ongoing rusfertide clinical trials, and performed a comprehensive review of our rusfertide safety database. Dosing of patients and enrollment in ongoing clinical trials with rusfertide resumed in the fourth quarter of 2021.

The FDA granted orphan drug designation for rusfertide for the treatment of PV in June 2020, and Fast Track designation for rusfertide for the treatment of PV in December 2020. The EMA granted orphan drug designation for rusfertide for treatment of PV in October 2020. The FDA granted Breakthrough Therapy Designation for rusfertide for the treatment of PV in June 2021. In April 2022, we received a letter from the FDA indicating the FDA’s intent to rescind Breakthrough Therapy Designation for rusfertide in PV. In June 2022, we voluntarily withdrew our Breakthrough Therapy Designation following correspondence with FDA and based on our internal analysis of the relative utility of Breakthrough Therapy Designation for Phase 3 trials and beyond. The FDA correspondence relating to the Breakthrough Therapy designation does not address the rusfertide Fast Track Designation, which remains active.

In keeping with our organizational prioritization of rusfertide in PV, plans to initiate trials of rusfertide in additional disease indications have been paused. This decision was influenced in part by the enactment of the Inflation Reduction Act (“IRA”) in the United States and includes previously planned trials of rusfertide in the subset of hereditary hemochromatosis patients with chronic arthropathy.

JNJ-2113 (formerly known as PN-235)

Our partnered Interleukin-23 receptor (“IL-23R”) antagonist compound JNJ-2113 is an orally delivered investigational drug that is designed to block biological pathways currently targeted by marketed injectable antibody drugs. Our orally stable peptide approach may offer a targeted therapeutic approach for gastrointestinal (“GI”) and systemic compartments as needed. We believe that, compared to antibody drugs, JNJ-2113 has the potential to provide clinical improvement in an oral medication with increased convenience and compliance and the opportunity for the earlier introduction of targeted oral therapy.

In May 2017, we entered into a worldwide license and collaboration agreement with Janssen Biotech, Inc. (“Janssen”), a Johnson & Johnson company, to co-develop and co-detail our IL-23R antagonist compounds, including PTG-200 (JNJ-67864238) and certain related compounds for all indications, including inflammatory bowel disease (“IBD”). PTG-200 was a first-generation investigational, orally delivered, IL-23R antagonist for the treatment of IBD. The agreement with Janssen was amended in May 2019 to expand the collaboration by supporting efforts towards second-generation IL-23R antagonists; and in July 2021 to, among other things, enable Janssen to independently research and develop collaboration compounds for multiple indications in the IL-23 pathway and further align our financial interests.

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During the fourth quarter of 2021, following a pre-specified interim analysis criteria, a portfolio decision was made by Janssen to advance second-generation product candidate JNJ-2113 (JNJ-77242113) based on its superior potency and overall pharmacokinetic and pharmacodynamic profile. A JNJ-2113 Phase 1 trial was completed in the fourth quarter of 2021.

In February 2022, Janssen initiated FRONTIER1, a 255-patient Phase 2b clinical trial of JNJ-2113 in moderate-to-severe plaque psoriasis, which was completed in December 2022. FRONTIER1 was a randomized, multicenter, double-blind, placebo-controlled study that evaluated three once-daily dosages and two twice-daily dosages of JNJ-2113 taken orally. The primary endpoint of the study is the proportion of patients achieving PASI-75 (a 75% improvement in skin lesions as measured by the Psoriasis Area and Severity Index) at 16 weeks. In March 2023, we announced positive topline results from the trial. JNJ-2113 achieved the study's primary efficacy endpoint, with a statistically significant greater proportion of patients who received JNJ-2113 achieving PASI-75 responses compared to placebo at Week 16 in all five of the study’s treatment groups. A clear dose response was observed across an eight-fold dose range. Treatment was well tolerated, with no meaningful difference in frequency of adverse events across treatment groups versus placebo. It is our expectation that JNJ-2113 will progress into a Phase 3 registrational study in plaque psoriasis on the strength of the FRONTIER1 data. Advancement of JNJ-2113 into a Phase 3 study and meeting the primary endpoint in that study would qualify us for milestone payments of $50 million and $115 million, respectively. Data will be presented from various pre-clinical and clinical studies on JNJ-2113 at medical conferences beginning in the second quarter of 2023.

Other Phase 2 studies of JNJ-2113 that Janssen has initiated include the SUMMIT study of JNJ-2113 for the treatment of moderate-to-severe plaque psoriasis expected to be completed in the second quarter of 2023 and FRONTIER2, a long-term extension study. A Phase 1 trial of an immediate release formulation of JNJ-2113 in healthy Japanese and Chinese adult participants is currently recruiting. Following the completion of Phase 2 studies of JNJ-2113 in plaque psoriasis, we expect Janssen to initiate a separate Phase 2 trial of JNJ-2113 in a second indication. Additional indications may include any or all of psoriatic arthritis, UC and CD.

During the fourth quarter of 2021, we received a $7.5 million milestone payment from Janssen triggered by the completion of data collection for JNJ-2113 Phase 1 activities. In the second quarter of 2022, we received a $25.0 million milestone payment in connection with the dosing of a third patient in FRONTIER1 during the first quarter of 2022. We will be eligible to receive a $10.0 million milestone payment in connection with the dosing of a third patient in the second Phase 2 trial of a second-generation candidate, a $50 million milestone upon dosing of a third patient in a Phase 3 trial for a second-generation compound for any indication, and a $115.0 million milestone payment upon a Phase 3 clinical trial for a second-generation compound for any indication meeting its primary clinical endpoint. We remain eligible for up to approximately $855.0 million in future development and sales milestone payments, in addition to the $112.5 million in nonrefundable payments from Janssen received to date. We also remain eligible to receive tiered royalties on net product sales at percentages ranging from mid-single digits to ten percent.

PN-943

PN-943 is a wholly owned, investigational, orally delivered, gut-restricted alpha 4 beta 7 (“α4β7”) specific integrin antagonist for IBD. During the second quarter of 2020, we initiated IDEAL, a 159 patient Phase 2 trial evaluating the safety, tolerability and efficacy of PN-943 in patients with moderate to severe UC. Enrollment in IDEAL was completed during the first quarter of 2022. The trial includes a 12-week induction period, which has been completed, and a 40-week extended treatment period. With the exception of completing the 40-week extended treatment period for eligible patients in the IDEAL trial, which is expected to be completed in the first quarter of 2023, we do not intend to dedicate further internal resources to clinical development or contract manufacturing activities for our PN-943 clinical program.

Discovery Platform

Our clinical assets are all derived from our proprietary discovery platform. Our platform enables us to engineer novel, structurally constrained peptides that are designed to retain key advantages of both orally delivered small molecules and injectable antibody drugs in an effort to overcome many of their limitations as therapeutic agents.

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Importantly, constrained peptides can be designed to potentially alleviate the fundamental instability inherent in traditional peptides to allow different delivery forms, such as oral, subcutaneous, intravenous, and rectal. We continue to use our peptide technology platform to discover product candidates against targets in disease areas with significant unmet medical needs. For example, we have a pre-clinical stage program to identify an orally active hepcidin mimetic, which we believe will be complementary to the injectable rusfertide for offering the best treatment options for PV, hereditary hemochromatosis and other potential erythropoietic and iron imbalance disorders.

Business Outlook

We are subject to risks and uncertainties as a result of the prolonged nature of the COVID-19 pandemic and emergent variants with increased transmissibility, even in those who are fully vaccinated. Some of the workforce trends starting during the pandemic have continued to lead to staffing shortages in settings such as clinical trial sites and healthcare offices. The future impact of COVID-19 on our activities will depend on a number of factors, including, but not limited to, the scope and magnitude of any resurgences in the outbreak and the spread of COVID-19 variants; the timing, extent, effectiveness and durability of COVID-19 vaccine programs or other treatments; and new travel and other restrictions and public health measures. We have experienced delays in our existing and planned clinical trials due to the worldwide impacts of the pandemic. Our future results of operations and liquidity could be adversely impacted by further delays in existing and planned clinical trials, continued difficulty in recruiting patients for these clinical trials, delays in manufacturing and collaboration activities, supply chain disruptions and the ongoing impact on our operating activities and employees. In addition, a recession or market correction related to or amplified by COVID-19 could materially affect our business.

We are currently operating in a period of economic uncertainty and capital markets disruption, which has been impacted by domestic and global monetary and fiscal policy, geopolitical instability, the ongoing military conflict between Russia and Ukraine and the rising tensions between China and Taiwan, a recessionary environment and historically high domestic and global inflation. In particular, the conflict in Ukraine has exacerbated market disruptions, including significant volatility in commodity prices, as well as supply chain interruptions, and has contributed to record inflation globally. The U.S. Federal Reserve and other central banks may be unable to contain inflation through more restrictive monetary policy and inflation may increase or continue for a prolonged period of time. Inflationary factors, such as increases in the cost of clinical supplies, interest rates, overhead costs and transportation costs may adversely affect our operating results. Also, the failure of Silicon Valley Bank and other banks in the United States in March 2023 has given rise to uncertainty in the security of amounts in deposit accounts uninsured by the Federal Deposit Insurance Corporation. We continue to monitor these events and the potential impact on our business. Although we do not believe that inflation has had a material impact on our financial position or results of operations to date, we may be adversely affected in the future due to domestic and global monetary and fiscal policy, supply chain constraints, consequences associated with COVID-19 and the ongoing conflict between Russia and Ukraine, and such factors may lead to increases in the cost of manufacturing our product candidates and delays in initiating trials.

Operations

We have incurred net losses in each year since inception and we do not anticipate achieving sustained profitability in the foreseeable future. Our net losses were $127.4 million, $125.6 million and $66.2 million for the years ended December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022, we had an accumulated deficit of $536.8 million. Substantially all of our net losses have resulted from costs incurred in connection with our research and development programs and from general and administrative costs associated with our operations. We expect to continue to incur significant research and development expenses and other expenses related to our ongoing operations, product development, and pre-commercialization activities. As a result, we expect to continue to incur losses in the future as we continue our development of, and seek regulatory approval for, our product candidates.

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Janssen License and Collaboration Agreement

On July 27, 2021, we entered into the Restated Agreement with Janssen, which amends and restates the Original Agreement, as amended by the First Amendment. Janssen is a related party to us as Johnson & Johnson Innovation - JJDC, Inc., a significant stockholder of ours, and Janssen are both subsidiaries of Johnson & Johnson. Upon the effectiveness of the Original Agreement, we received a non-refundable, upfront cash payment of $50.0 million from Janssen. Upon the effectiveness of the First Amendment, we received a $25.0 million payment from Janssen in 2019. In the first quarter of 2020, we received a $5.0 million payment triggered by the successful nomination of a second-generation IL-23R antagonist development compound. In the fourth quarter of 2021, we received a $7.5 million milestone payment from Janssen triggered by completion of the data collection for JNJ-2113 Phase 1 activities. In the second quarter of 2022, we received a $25.0 million milestone payment in connection with the dosing of a third patient in FRONTIER1 during the first quarter of 2022. See Note 3 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

Critical Accounting Polices and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with United States generally accepted accounting principles. The preparation of these consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the consolidated financial statements, as well as the reported revenue generated, and the expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, and the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. We believe that the accounting policies discussed below are critical to understanding our historical and future performance, as these policies relate to the more significant areas involving management’s judgments and estimates.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, we evaluate our estimates, including those related to revenue recognition, accruals for research and development activities, stock-based compensation, income taxes, marketable securities and leases. Estimates related to revenue recognition include actual costs incurred versus total estimated costs of our deliverables to determine percentage of completion in addition to the application and estimates of potential revenue constraints in the determination of the transaction price under its license and collaboration agreements. We base these estimates on historical and anticipated results, trends and various other assumptions that we believe are reasonable under the circumstances, including assumptions as to forecasted amounts and future events.

Due to the COVID-19 pandemic, military conflict between Ukraine and Russia, rising tensions between China and Taiwan and inflationary pressures, among other factors, there has been uncertainty and disruption in the global economy and financial markets. We have taken into consideration any known impacts in our accounting estimates to date and are not aware of any additional specific events or circumstances that would require any additional updates to our estimates or judgments or a revision of the carrying value of our assets or liabilities as of the date of the filing of this Annual Report on Form 10-K. These estimates may change as new events occur and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions.

Revenue Recognition

Under Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”), we recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the

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consideration which we expect to receive in exchange for those goods or services. To determine revenue recognition for arrangements that we determine are within the scope of ASC 606, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy a performance obligation. We apply the five-step model to contracts when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services we transfer to the customer. At contract inception, we assess the goods or services promised within each contract, determine those that are performance obligations, and assess whether each promised good or service is distinct. We then recognize as revenue the amount of the transaction price that is allocated to the respective performance obligations when (or as) the performance obligations are satisfied. We constrain our estimate of the transaction price up to the amount (the “variable consideration constraint”) that a significant reversal of recognized revenue is not probable.

Licenses of intellectual property: If a license to our intellectual property is determined to be distinct from the other performance obligations identified in an arrangement, we recognize revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, we utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring proportional performance for purposes of recognizing revenue from non-refundable, upfront fees. We evaluate the measure of proportional performance each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.

Milestone payments: At the inception of each arrangement or amendment that includes development, regulatory or commercial milestone payments, we evaluate whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price. ASC 606 suggests two alternatives to use when estimating the amount of variable consideration: the expected value method and the most likely amount method. Under the expected value method, an entity considers the sum of probability-weighted amounts in a range of possible consideration amounts. Under the most likely amount method, an entity considers the single most likely amount in a range of possible consideration amounts. Whichever method is used should be consistently applied throughout the life of the contract; however, it is not necessary for us to use the same approach for all contracts. We expect to use the most likely amount method for development and regulatory milestone payments. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within our control or the control of the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. If there is more than one performance obligation, the transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis. We recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, we re-evaluate the probability or achievement of each such milestone and any related constraint, and if necessary, adjust our estimates of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment.

Any potential milestone payments that we determine are not associated with performance obligations as defined under the contract are excluded from the transaction price and are recognized as the triggering event occurs.

Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, where the license is deemed to be the predominant item to which the royalties relate, we recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Upfront payments and fees are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until we perform our obligations under these arrangements. Amounts payable to us are recorded as accounts receivable when our right to consideration is unconditional. Amounts payable to us and not yet billed to the collaboration partner are recorded as contract assets. We do not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less.

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Contractual cost sharing payments made to a customer or collaboration partner are accounted for as a reduction to the transaction price if such payments are not related to distinct goods or services received from the customer or collaboration partner.

Contracts may be amended to account for changes in contract specifications and requirements. Contract modifications exist when the amendment either creates new, or changes existing, enforceable rights and obligations. When contract modifications create new performance obligations and the increase in consideration approximates the standalone selling price for goods and services related to such new performance obligations, as adjusted for specific facts and circumstances of the contract, the modification is considered to be a separate contract and revenue is recognized prospectively. If a contract modification is not accounted for as a separate contract, we account for the promised goods or services not yet transferred at the date of the contract modification (the remaining promised goods or services) prospectively, as if it were a termination of the existing contract and the creation of a new contract, if the remaining goods or services are distinct from the goods or services transferred on or before the date of the contract modification. We account for a contract modification as if it were a part of the existing contract if the remaining goods or services are not distinct and, therefore, form part of a single performance obligation that is partially satisfied at the date of the contract modification. In such case the effect that the contract modification has on the transaction price, and on the entity’s measure of progress toward complete satisfaction of the performance obligation, is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) at the date of the contract modification (the adjustment to revenue is made on a cumulative catch-up basis).

Research and Development Costs

Research and development costs are expensed as incurred, unless there is an alternate future use in other research and development projects or otherwise. Research and development costs include salaries and benefits, stock-based compensation expense, laboratory supplies and facility-related overhead, outside contracted services, including clinical trial costs, manufacturing and process development costs for both clinical and pre-clinical materials, research costs, development milestone payments under license and collaboration agreements, and other consulting services.

We accrue for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of pre-clinical studies and clinical trials, and contract manufacturing activities. We record the estimated costs of research and development activities based upon the estimated services provided but not yet invoiced and we include these costs in accrued expenses and other payables in our consolidated balance sheets and within research and development expense in our consolidated statements of operations. We accrue for these costs based on various factors such as estimates of the work completed and in accordance with agreements established with our third-party service providers. As actual costs become known, we adjust our accrued liabilities. We have not experienced any material differences between accrued liabilities and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled, the rate of patient enrollment and the number and location of sites activated may vary from our estimates and may result in adjustments to our research and development expenses in future periods. Changes in these estimates that result in material changes to our accruals could materially affect our results of operations.

Recent Accounting Pronouncements

Information regarding recent accounting pronouncements applicable to us is included in Note 2 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K.

Components of Our Results of Operations

License and Collaboration Revenue

Our license and collaboration revenue is derived from payments we receive under the Janssen License and Collaboration Agreement. See Note 3 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

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Research and Development Expenses

Research and development expenses represent costs incurred to conduct research, such as the discovery and development of our product candidates. We recognize all research and development costs as they are incurred unless there is an alternative future use in other research and development projects or otherwise. Non-refundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received, rather than when payment has been made. In instances where we enter into agreements with third parties to provide research and development services to us, costs are expensed as services are performed. Amounts due under such arrangements may be either fixed fee or fee for service and may include upfront payments, monthly payments, and payments upon the completion of milestones or the receipt of deliverables.

Research and development expenses consist primarily of the following:

We recognize the amounts related to our Australian research and development refundable cash tax incentive that are not subject to refund provisions as a reduction of research and development expenses. The research and development tax incentives are recognized when there is reasonable assurance that the incentives will be received, the relevant expenditure has been incurred and the amount of the consideration can be reliably measured. We evaluate our eligibility under the tax incentive program as of each balance sheet date and make accruals and related adjustments based on the most current and relevant data available. We may alternatively be eligible for a taxable credit in the form of a non-cash tax incentive. We recognize the amounts from grants under government programs as a reduction of research and development expenses when the related research costs are incurred.

We allocate direct and indirect costs incurred to product candidates when they enter clinical development. For product candidates in clinical development, direct costs consist primarily of clinical, pre-clinical, and drug discovery costs, costs of supplying drug substance and drug product for use in clinical and pre-clinical studies, including clinical manufacturing costs, contract research organization fees, and other contracted services pertaining to specific clinical and pre-clinical studies. Indirect costs allocated to our product candidates on a program-specific basis include research and development employee salaries, benefits, and stock-based compensation, and indirect overhead and other administrative support costs. Program-specific costs are unallocated when the clinical expenses are incurred for our early-stage research and drug discovery projects as our internal resources, employees and infrastructure are not tied to any one research or drug discovery project and are typically deployed across multiple projects. As such, we do not provide financial information regarding the costs incurred for early stage pre-clinical and drug discovery programs on a program-specific basis prior to the clinical development stage.

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We expect our research and development expenses to decrease in the near term as we continue to de-prioritize our PN-943 clinical program and streamline certain discovery programs to focus our resources toward progressing our rusfertide program into later stage clinical trials and preparing for commercialization. The process of conducting research, identifying potential product candidates and conducting pre-clinical and clinical trials necessary to obtain regulatory approval and commencing pre-commercialization activities is costly and time intensive. We may never succeed in achieving marketing approval for our product candidates regardless of our costs and efforts. The probability of success of our product candidates may be affected by numerous factors, including pre-clinical data, clinical data, competition, manufacturing capability, our cost of goods to be sold, our ability to receive, and the timing of, regulatory approvals, market conditions, and our ability to successfully commercialize our products if they are approved for marketing. As a result, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization and sale of any of our product candidates. Our research and development programs are subject to change from time to time as we evaluate our priorities and available resources. With the exception of completing the 40-week extended treatment period for eligible patients in the Phase 2 IDEAL trial, which we expect to be completed in the first quarter of 2023, we do not intend to dedicate further internal resources to clinical development or contract manufacturing activities for our PN-943 clinical program. We will continue to explore out-licensing opportunities globally.

General and Administrative Expenses

General and administrative expenses consist of personnel costs, allocated facilities costs and other expenses for outside professional services, including legal, human resources, audit and accounting services, and pre-commercialization expenses, including selling and marketing costs. Personnel costs consist of salaries, benefits and stock-based compensation. Allocated expenses consist of expenses for rent and maintenance of facilities, information technology, depreciation and amortization expense and other administrative supplies. We expect to continue to incur expenses supporting our continued operations as a public company, including expenses related to compliance with the rules and regulations of the SEC and those of the national securities exchange on which our securities are traded, insurance expenses, investor relations expenses, audit fees, professional services and general overhead and administrative costs.

Interest Income

Interest income consists of interest earned on our cash, cash equivalents, and marketable securities, which is comprised of contractual interest, premium amortization and discount accretion.

Interest Expense

Interest expense consists of interest recognized on our long-term debt, which is comprised of contractual interest, amortization of origination fees and other issuance costs, and accretion of final payment fees.

Loss on Early Repayment of Debt

Loss on early repayment of debt consists of prepayment and final payment fees paid upon the early repayment of our long-term debt.

Other Expense, Net

Other expense, net consists primarily of amounts related to foreign exchange gains and losses and related items.

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Results of Operations

Year Ended December 31, Dollar %

(Dollars in thousands)

Operating expenses:

Other expense, net (80) (149) 69 (46)

(1) Includes $14.7 million and $9.0 million of non-cash stock-based compensation expense for the years ended December 31, 2022 and 2021, respectively.

(2) Includes $9.5 million and $7.4 million of non-cash stock-based compensation expense for the years ended December 31, 2022 and 2021, respectively.

*Percentage not meaningful

License and Collaboration Revenue

License and collaboration revenue decreased $0.8 million, or 3%, from $27.4 million for the year ended December 31, 2021 to $26.6 million for the year ended December 31, 2022. The decrease in revenue was primarily due to a decrease in services under the Janssen License and Collaboration Agreement recognized based on proportional performance. We completed our performance obligation pursuant to the collaboration as of June 30, 2022.

We determined that the final transaction price of the initial performance obligation under the Restated Agreement is $131.7 million as of December 31, 2022, an increase of $25.2 million from the transaction price of $106.5 million as of December 31, 2021. In order to determine the transaction price, we evaluated all payments to be received during the duration of the contract, net of development costs reimbursement expected to be payable to Janssen. The transaction price as of December 31, 2022 includes $112.5 million of nonrefundable payments received as of June 30, 2022, $17.9 million of reimbursement from Janssen for services performed for IL-23 receptor antagonist compound research and other services, and variable consideration consisting of $8.2 million of development cost reimbursement from Janssen, partially offset by $6.9 million of net cost reimbursement due to Janssen for services performed.

Research and Development Expenses

Year Ended December 31, Dollar %

(Dollars in thousands)

Clinical and development expense — PTG-200 53 23 30 130

Clinical and development expense — PTG-100 248 374 (126) (34)

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We had 82 and 92 full-time equivalent research and development employees as of December 31, 2022 and 2021, respectively. Research and development expenses for the year ended December 31, 2022 included increases of $5.7 million in stock-based compensation expense and $4.7 million of other personnel-related expenses compared to the year ended December 31, 2021.

General and Administrative Expenses

General and administrative expenses increased $4.5 million, or 17%, from $27.2 million for the year ended December 31, 2021 to $31.7 million for the year ended December 31, 2022, primarily due to increases of $2.2 million in personnel-related expenses and $2.3 million in other expenses to support the growth of our business. The increase in personnel-related expenses was primarily due to an increase of $2.1 million in stock-based compensation expense.

We had 23 and 26 full-time equivalent general and administrative employees as of December 31, 2022 and 2021, respectively.

Interest Income

Interest income increased $3.6 million, from $0.4 million for the year ended December 31, 2021 to $4.1 million for the year ended December 31, 2022. This increase was primarily due to higher yields on invested balances during a period of increasing interest rates compared to the prior year period.

Comparison of the Years Ended December 31, 2021 and 2020

Year Ended December 31, Dollar %

(Dollars in thousands)

Operating expenses:

Interest expense — (598) 598 (100)

Loss on early repayment of debt — (585) 585 (100)

(1) Includes $9.0 million and $4.1 million of non-cash stock-based compensation expense for the years ended December 31, 2021 and 2020, respectively.

(2) Includes $7.4 million and $3.8 million of non-cash stock-based compensation expense for the years ended December 31, 2021 and 2020, respectively.

License and Collaboration Revenue

License and collaboration revenue decreased $1.3 million, or 4%, from $28.6 million for the year ended December 31, 2020 to $27.4 million for the year ended December 31, 2021. The decrease in license and collaboration revenue was primarily related to a decrease in services provided under the Janssen License and Collaboration Agreement recognized based on proportional performance, partially offset by an $8.0 million cumulative catch-up amount recognized during the year ended December 31, 2021. This cumulative catch-up was primarily the result of an

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acceleration of our cumulative performance completed, following the execution of the Restated Agreement, which reduced our remaining performance obligation. Revenue for the year ended December 31, 2020 included an update in the amounts forecasted for future services remaining to be performed under the Janssen License and Collaboration Agreement which correspondingly increased our overall cumulative percentage of completion of our performance obligation during year ended December 31, 2020, along with continued performance and delivery of services under the Janssen License and Collaboration Agreement.

We determined that the transaction price of the initial performance obligation under the Restated Agreement was $106.5 million as of December 31, 2021, an increase of $7.9 million from the transaction price of $98.6 million as of December 31, 2020, under the Original Agreement. In order to determine the transaction price, we evaluated all payments expected to be received during the duration of the contract, net of development costs reimbursement expected to be payable to Janssen. We determined that the transaction price included $87.5 million of nonrefundable payments received as of December 31, 2021, $17.9 million of reimbursement from Janssen for services performed for IL-23 receptor antagonist compound research and other services and estimated variable consideration consisting of $8.2 million of development cost reimbursement from Janssen, partially offset by $7.1 million of net cost reimbursement due to Janssen for services performed. The increase in transaction price from December 31, 2020 to December 31, 2021 was due primarily to reductions in both the remaining services to be performed by us under the Restated Agreement and the remaining shared development costs under the Restated Agreement.

Research and Development Expenses

Year Ended December 31, Dollar %

(Dollars in thousands)

Clinical and development expense — PN-232 2,037 — 2,037 *

Clinical and development expense — PTG-200 23 925 (902) (98)

Clinical and development expense — PTG-100 374 540 (166) (31)

*Percentage not meaningful

Research and development expenses increased $51.5 million, or 69%, from $74.5 million for the year ended December 31, 2020 to $126.0 million for the year ended December 31, 2021. The increase was primarily due to an increase of $23.0 million in rusfertide clinical trial and development costs as clinical trials have enrolled and progressed, including the ongoing REVIVE and PACIFIC Phase 2 trials in PV, which began in December 2019 and the first quarter of 2021, respectively, and HH, which began in early 2020, and clinical and contract manufacturing activities incurred in 2021 in support of the REVIVE and PACIFIC Phase 2 trials and planned VERIFY global Phase 3 clinical trial of rusfertide in PV; an increase of $14.3 million in PN-943 clinical trial and development costs and contract manufacturing costs primarily related to the Phase 2 IDEAL trial in UC initiated during the second quarter of 2020; an increase of $6.5 million in preclinical and drug discovery research expenses; an increase of $4.5 million of clinical trial and development costs for the Phase 1 JNJ-2113 initiated in December 2020; an increase of $4.0 million of expenses related to milestone payments and obligations under the Zealand Agreement for rusfertide pursuant to the resolution of related arbitration; and an increase of $2.0 million of clinical trial and development costs for the Phase 1 PN-232 study initiated in May 2021. These increases were partially offset by a $1.7 million increase in grant and accrued refundable cash tax incentives and a decrease of $0.9 million in PTG-200 clinical trial and development expenses under the Janssen License

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and Collaboration Agreement due to our delivery of substantially all agreed-upon services for the PTG-200 Phase 2 clinical trial prior to 2021.

We had 92 and 59 full-time equivalent research and development employees as of December 31, 2021 and 2020, respectively. Research and development expenses for the year ended December 31, 2021 included increases of $4.9 million in stock-based compensation expense and $5.3 million of other personnel-related expenses compared to the year ended December 31, 2020.

General and Administrative Expenses

General and administrative expenses increased $8.6 million, or 46%, from $18.6 million for the year ended December 31, 2020 to $27.2 million for the year ended December 31, 2021, primarily due to increases of $5.2 million in personnel-related expenses, $1.6 million in consulting expenses, $0.9 million in market research expenses, $0.5 million in recruiting expenses to support the growth of our business, and $0.3 million in insurance expense. The increase in personnel-related expenses was primarily due to an increase of $3.6 million in stock-based compensation expense and $1.6 million in wages and salaries.

We had 26 and 20 full-time equivalent general and administrative employees as of December 31, 2021 and 2020, respectively.

Interest Income

Interest income decreased $0.5 million, or 51%, from $0.9 million for the year ended December 31, 2020 to $0.4 million for the year ended December 31, 2021. This decrease was primarily due to the low interest rate environment in 2021 and a change in the mix of marketable securities compared to the prior year period, despite higher interest-earning asset balances.

Interest Expense

Interest expense of $0.6 million for the year ended December 31, 2020 was comprised of interest expense on our long-term debt under our term credit facility. We prepaid our outstanding long-term debt under our term credit facility during the second quarter of 2020. We executed a payoff letter to release all obligations under the term credit facility during the third quarter of 2021.

Loss on Early Repayment of Debt

Loss on early repayment of debt of $0.6 million for the year ended December 31, 2020 was comprised of prepayment and final payment fees paid in connection with the early repayment of our term loan in June 2020. We had no debt outstanding at December 31, 2021.

Other Expense, Net

Other expense, net was $0.1 million for the year ended December 31, 2021 compared to zero for the year ended December 31, 2020. The change was due primarily to an increase in foreign exchange losses.

Income Tax Expense

Income tax expense decreased $1.3 million, or 100%, from $1.3 million for the year ended December 31, 2020 to zero for the year ended December 31, 2021. Our effective income tax rate was 0% for the year ended December 31, 2021 as compared to 2.0% for the year ended December 31, 2020. Our effective income tax rate differed from our federal statutory rate of 21% primarily because our losses could not be benefited due to our full valuation allowance position. During the second quarter of 2020, our Australia subsidiary sold beneficial rights to discovery intellectual property to our U.S. entity, and the U.S. entity reimbursed the Australia subsidiary for certain direct development costs.

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Upon completion of the sale, we analyzed tax planning strategies and future income and concluded that a valuation allowance was necessary for our Australia subsidiary. Income tax expense for the year ended December 31, 2020 reflected the sale of intellectual property rights, cost reimbursements and related adjustments to the deferred tax asset, establishment of a valuation allowance and certain uncertain tax position liabilities. We maintained a full valuation allowance on our tax position at December 31, 2021.

Liquidity and Capital Resources

Liquidity and Capital Expenditures

Sources of Liquidity

Historically, we have funded our operations primarily from net proceeds from the sale of shares of our common stock and receipt of payments under collaboration agreements.

In August 2022, we entered into an Open Market Sale AgreementSM (the “Sales Agreement”), pursuant to which we may offer and sell up to $100.0 million of shares of our common stock from time to time in “at-the-market” offerings (the “2022 ATM Facility”). As of December 31, 2022, no sales were made under the 2022 ATM Facility.

In June 2021, we completed an underwritten public offering of 3,046,358 shares of common stock at a public offering price of $37.75 per share and issued an additional 456,953 shares of common stock at a public offering price of $37.75 per share following the underwriters’ exercise of their option to purchase additional shares. Net proceeds, after deducting underwriting commission and offering costs paid by us, were $123.8 million.

In December 2020, we completed an underwritten public offering of 4,761,904 shares of common stock at a public offering price of $21.00 per share and issued an additional 714,285 shares of our common stock at a price of $21.00 per share following the underwriters’ exercise of their option to purchase additional shares. Net proceeds, after deducting underwriting commissions and offering costs paid by us, were $107.6 million.

In May 2020, we completed an underwritten public offering of 7,000,000 shares of our common stock at a public offering price of $14.00 per share, and we issued an additional 1,050,000 shares of our common stock at a price of $14.00 per share following the underwriters’ exercise of their option to purchase additional shares. Net proceeds, after deducting underwriting commissions and offering costs paid by us, were $105.3 million.

In November 2019, we entered into an Open Market Sale AgreementSM (the “Prior Sales Agreement”), pursuant to which we could offer and sell up to $75.0 million of shares of our common stock from time to time in “at-the-market” offerings (the “2019 ATM Facility”). During the year ended December 31, 2020, we sold 2,483,719 shares under the 2019 ATM Facility for net proceeds of $41.9 million. No shares were sold under the 2019 ATM Facility during the year ended December 31, 2021. During the year ended December 31, 2022, we sold 422,367 shares of our common stock under the 2019 ATM Facility for net proceeds of $14.6 million. The Prior Sales Agreement was terminated in connection with and replaced by the Sales Agreement in August 2022.

We have received a total of $112.5 million in non-refundable payments from Janssen since the inception of the Janssen License and Collaboration Agreement in 2017 through December 31, 2022, as follows:

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We also expect to receive payments for services provided under the collaboration agreement and we may make in-kind payment reimbursements to Janssen for certain costs they have incurred pursuant to the cost sharing terms of the agreement.

Pursuant to the Restated Agreement, we may be eligible to receive clinical development, regulatory and sales milestones, if and when achieved. Upcoming potential development milestones for second-generation products include:

Capital Requirements

As of December 31, 2022, we had $237.4 million of cash, cash equivalents and marketable securities and an accumulated deficit of $536.8 million. Our capital expenditures were $0.8 million, $1.1 million and $0.5 million for the years ended December 31, 2022, 2021 and 2020, respectively. Our primary uses of cash are to fund our operating expenses, primarily related to our research and development expenditures, general and administrative costs and pre-commercialization costs. Cash used in operating activities is impacted by the timing of when we pay these expenses. As of the date of this filing, we believe, based on our current operating plan and assumptions that our existing cash, cash equivalents and marketable securities will be sufficient to meet our anticipated operating and capital expenditure requirements for at least the next 12 months. We have based this estimate on assumptions that may prove to be wrong. We could utilize our available capital resources sooner than we currently expect if, for instance, our planned pre-clinical and clinical trials are successful or expanded, our product candidates enter new and more advanced stages of clinical development, we experience significant delays or difficulties in commencing, enrolling or completing clinical studies, our newer product clinical trials advance beyond the discovery stage, or various other factors. We expect that our cash burn will be lower in 2023 due to our research and development expenses decreasing in the near term as we continue to de-prioritize our PN-943 clinical program and streamline certain discovery programs to focus our resources toward progressing our rusfertide program into later stage clinical trials and preparing for commercialization.

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We anticipate that we will need to raise substantial additional funding to advance rusfertide through clinical development and toward potential regulatory approval and to develop, acquire, or in-license other potential product candidates. Our future funding requirements will depend on many factors, including:

● the costs necessary to attract, hire and retain qualified personnel;

Such additional funding may come from various sources, including raising additional capital, seeking access to debt, and seeking additional collaborative or other arrangements with partners, but such funding may not be available on terms acceptable to us, if at all. As discussed in Part I, Item1A.“Risk Factors”, we are currently operating in a period of economic uncertainty and capital markets disruption, which has been significantly impacted by domestic and global monetary and fiscal policy, and geopolitical instability, among other factors. A future recession or market correction related to COVID-19 or due to other factors, including significant geopolitical or macroeconomic events, could materially affect our business and our access to credit and financial markets.

Any failure to raise capital as and when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. Further, our operating plans may change, and we may need additional funds to meet operational needs and capital requirements for clinical trials, other research and development activities and pre-commercialization costs. If we do raise additional capital through public or private equity offerings or convertible debt securities, the ownership interest of our existing stockholders could be diluted, and the terms of these securities

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could include liquidation or other preferences that could adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we could be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Because of the numerous risks and uncertainties associated with the development and commercialization of our product candidates, we are unable to fully estimate the amounts of increased capital outlays and operating expenditures associated with our current and anticipated product development programs. For additional information, see Part I, Item 1A, Risk Factors—“Risks Related to our Financial Position and Capital Requirements”.

The following table includes our cash flow data for the periods indicated (in thousands):

Year Ended December 31,

(Dollars in thousands)

Cash Used in Operating Activities

Cash used in operating activities during the year ended December 31, 2022, was $108.1 million, consisting primarily of our net loss of $127.4 million and a net change of $7.8 million in net operating assets and liabilities, partially offset by certain non-cash items, including $24.2 million of stock-based compensation expense. The $0.3 million increase in cash flow used in operating activities during the year ended December 31, 2022, as compared to the year ended December 31, 2021, was primarily due to a $1.8 million increase in our net loss, a $4.5 million net change in net operating assets and liabilities, and a $1.8 million net change in other non-cash items, partially offset by a $7.8 million increase in stock-based compensation expense.

Cash used in operating activities during the year ended December 31, 2021, of $107.9 million consisted primarily of our net loss of $125.6 million, partially offset by certain non-cash items including $16.4 million of stock-based compensation expense. The $35.4 million increase in cash flow used in operating activities during the year ended December 31, 2021, as compared to the year ended December 31, 2020, was primarily due to a $59.4 million increase in our net loss, partially offset by certain non-cash items including an increase of $8.5 million of stock-based compensation expense, and a $14.2 million change in decrease in deferred revenue.

Cash Provided by (Used in) Investing Activities

Cash provided by investing activities for the year ended December 31, 2022, was $91.5 million, consisting of proceeds from maturities of marketable securities of $307.1 million, partially offset by purchases of marketable securities of $214.9 million and purchases of property and equipment of $0.8 million. The $107.3 million increase in cash provided by investing activities for the year ended December 31, 2022, as compared to the year ended December 31, 2021, was primarily related to a decrease of $71.7 million in purchases of marketable securities and an increase of $35.3 million in proceeds from maturities of marketable securities. Purchases of property and equipment were primarily related to purchases of laboratory and computer equipment.

Cash used in investing activities for the year ended December 31, 2021, was $15.9 million, consisting of purchases of marketable securities of $286.6 million and purchases of property and equipment of $1.1 million, partially offset by proceeds from maturities of marketable securities of $271.8 million. The $75.1 million decrease in cash used in investing activities for the year ended December 31, 2021, as compared to the year ended December 31, 2020, was primarily due to an increase of $82.3 million in proceeds from maturities of marketable securities. Purchases of property and equipment were primarily related to purchases of laboratory equipment, furniture and computer equipment.

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Cash Provided by Financing Activities

Cash provided by financing activities for the year ended December 31, 2022, was $18.8 million, consisting primarily of net cash proceeds from sales of $14.6 million under the 2019 ATM Facility and proceeds from the issuance of common stock upon the exercise of stock options and purchases of common stock under our employee stock purchase plan of $4.4 million. The $111.1 million decrease in cash provided by financing activities for the year ended December 31, 2022, as compared to the year ended December 31, 2021, was primarily due to a $123.8 million decrease in cash proceeds from our public offerings of common stock, and a $1.8 million decrease in proceeds from the issuance of common stock upon exercise of stock options and purchases of common stock under our employee stock purchase plan. These decreases were partially offset by $14.6 million increase in cash proceeds from ATM sales.

Cash provided by financing activities for the year ended December 31, 2021, was $129.9 million, consisting primarily of cash proceeds from our public offerings of common stock of $123.8 million and proceeds from the issuance of common stock upon the exercise of stock options and purchases of common stock under our employee stock purchase plan of $6.3 million. The $117.7 million decrease in cash provided by financing activities for the year ended December 31, 2021, as compared to the year ended December 31, 2020, was primarily due to an $89.5 million decrease in cash proceeds from our public offerings of common stock, a $42.1 million decrease in cash proceeds from ATM sales. These decreases were partially offset by $10.5 million related to the early repayment of long-term debt in 2020 and a $3.5 million increase in proceeds from the issuance of common stock upon exercise of stock options and purchases of common stock under our employee stock purchase plan.

Contractual Obligations and Other Commitments

In the normal course of business, we enter into agreements with contract service providers to assist in the performance of our research and development activities and clinical and commercial manufacturing activities. Subject to required notice periods and our obligations under binding commitments, we can elect to discontinue the work under these agreements at any time. We expect to enter into additional clinical development, contract research, clinical and commercial manufacturing, supplier agreements and collaborative research agreements in the future, which may require upfront payments and long-term commitments of capital resources.

Our contractual obligations include minimum lease payments under our operating lease obligations. On July 2, 2021, we entered into a second amendment to our facility lease agreement dated as of March 2017, to lease approximately 15,000 square feet of additional office space in Newark, California. See Note 10 to the Consolidated Financial Statements elsewhere in this Annual Report on Form 10-K for additional information.

Under the Restated Agreement, we share with Janssen certain development, regulatory and compound supply costs. The actual amounts that we pay Janssen or that Janssen pays us will depend on numerous factors, some of which are outside of our control and some of which are contingent upon the success, if achieved, of certain development and regulatory activities. See Note 3 to the Consolidated Financial Statements elsewhere in this Annual Report on Form 10- K for additional information.

In June 2012, we entered into the Zealand Agreement to identify, optimize and develop novel disulfide-rich peptides to discover a hepcidin mimetic. We amended the Zealand Agreement on February 28, 2014, at which point we assumed responsibility for the development program. On January 23, 2020, we initiated arbitration proceedings with the International Court of Arbitration of the International Chamber of Commerce against Zealand. On August 4, 2021, we and Zealand agreed to resolve the dispute and reached an Arbitration Resolution Agreement. See Note 7 and Note 11 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

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Item 7A.Quantitative and Qualitative Disclosures about Market Risk

We are exposed to market risks in the ordinary course of our business. These risks primarily include interest rate sensitivities related to our interest-earning investments and inflation risk affecting labor costs and clinical trial costs.

Interest Rate Fluctuation Risk

We had $237.4 million and $326.9 million in cash, cash equivalents and marketable securities at December 31, 2022 and 2021, respectively. Our cash and cash equivalents consist of cash, money market funds, commercial paper and government bonds. Marketable securities consist of corporate bonds, commercial paper, government bonds and highly rated supranational and sovereign government securities. A portion of our investments may be subject to interest rate risk and could fall in value if market interest rates continue to increase. Based on our interest rate sensitivity analysis, a hypothetical 100 basis point increase in interest rates would increase our interest income by approximately $1.8 million, while an immediate 100 basis point decrease in interest rates would decrease our interest income by approximately $2.3 million.

Approximately $2.5 million and $1.1 million of our cash balance was located in Australia at December 31, 2022 and 2021, respectively. Our expenses, except those related to our Australian operations, are generally denominated in U.S. dollars. For our operations in Australia, the majority of our expenses are denominated in Australian dollars. To date, we have not had a formal hedging program with respect to foreign currency, but we may do so in the future if our exposure to foreign currency becomes more significant. A 10% increase or decrease in current exchange rates would not have a material effect on our results of operations.

Inflation Fluctuation Risk

Inflation has increased during the period covered by this report and is expected to continue to at elevated levels or even increase for the near future. Inflation generally affects us by increasing our costs, such as the cost of labor and research and development contract costs. We do not believe inflation has had a material effect on our results of operations during the year ended December 31, 2022.

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Item 8. Financial Statements and Supplementary Data

PROTAGONIST THERAPEUTICS, INC.

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

AAW

Audited Consolidated Financial Statements Page

Report of Independent Registered Public Accounting Firm (PCAOB ID: 42) 74

Consolidated Balance Sheets 76

Consolidated Statements of Operations 77

Consolidated Statements of Comprehensive Loss 78

Consolidated Statements of Stockholders’ Equity 79

Consolidated Statements of Cash Flows 80

Notes to the Consolidated Financial Statements 81

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Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of Protagonist Therapeutics, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Protagonist Therapeutics, Inc. (the Company) as of December 31, 2022 and 2021, 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, 2022, 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, 2022 and 2021, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2022, 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) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of 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 separate opinions on the critical audit matter or on the accounts or disclosures to which it relates.

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Accrued clinical and research related expenses

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 2020.

San Mateo, California

March 15, 2023

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Balance Sheets

(In thousands, except share data)

December 31,

Assets

Current assets:

Receivable from collaboration partner – related party 10 1,566

Research and development tax incentive receivable — 2,792

Prepaid expenses and other current assets 5,712 9,478

Property and equipment, net 1,565 1,798

Restricted cash – noncurrent 225 225

Operating lease right-of-use asset 3,061 4,936

Liabilities and Stockholders’ Equity

Current liabilities:

Payable to collaboration partner – related party 69 899

Accrued expenses and other payables 24,955 37,716

Deferred revenue – related party — 1,601

Operating lease liability – current 2,515 2,200

Operating lease liability – noncurrent 1,141 3,658

Commitments and contingencies

Stockholders’ equity:

Accumulated other comprehensive loss (359) (299)

Total liabilities and stockholders’ equity $ 247,928 $ 347,695

The accompanying notes are an integral part of these consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Operations

(In thousands, except share and per share data)

Year Ended December 31,

Operating expenses:

Interest expense — — (598)

Loss on early repayment of debt — — (585)

Other expense, net (80) (149) (46)

Income tax expense — — (1,305)

Net loss per share, basic and diluted $ (2.60) $ (2.71) $ (1.92)

The accompanying notes are an integral part of these consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Comprehensive Loss

(In thousands)

Year Ended December 31,

Other comprehensive loss:

Loss (gain) on translation of foreign operations (149) (182) 266

Unrealized gain (loss) on marketable securities 89 (145) (17)

The accompanying notes are an integral part of these consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Stockholders’ Equity

(In thousands, except share data)

Accumulated

Additional Other Total

Common Paid-In Comprehensive Accumulated Stockholders’

Stock Capital (Loss) Gain Deficit Equity

Shares Amount

Stock-based compensation expense — — 7,899 — — 7,899

Other comprehensive gain — — — 249 — 249

Stock-based compensation expense — — 16,395 — — 16,395

Other comprehensive loss — — — (327) — (327)

Stock-based compensation expense — — 24,202 — — 24,202

Other comprehensive loss — — — (60) — (60)

The accompanying notes are an integral part of these consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Cash Flows

(In thousands)

Year Ended December 31,

Cash Flows from Operating Activities

Operating lease right-of-use asset amortization 2,335 1,962 1,775

Depreciation and amortization 1,034 813 948

Change in deferred tax asset — — 1,438

Loss on early repayment of debt — — 585

Changes in operating assets and liabilities:

Prepaid expenses and other assets 3,754 (3,227) (1,102)

Payable to collaboration partner – related party (830) (1,833) 1,471

Operating lease liability (2,661) (2,049) (1,941)

Other liabilities — (121) 121

Cash Flows from Investing Activities

Purchases of property and equipment (795) (1,101) (471)

Cash Flows from Financing Activities

Issuance costs related to prior period common stock offering 25 — —

Early repayment of long-term debt — — (10,524)

Issuance costs related to long-term debt — — (14)

Supplemental Disclosure of Cash Flow Information:

Cash paid for interest $ — $ — $ 438

The accompanying notes are an integral part of these consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Notes to Consolidated Financial Statements

Note 1. Organization and Description of Business

Protagonist Therapeutics, Inc. (the “Company”) is headquartered in Newark, California. The Company is a biopharmaceutical company with peptide-based new chemical entities rusfertide and JNJ-2113 (formerly known as PN - 235) in different stages of clinical development, all derived from the Company’s proprietary technology platform. The Company’s clinical programs fall into two broad categories of diseases: (i) hematology and blood disorders, and (ii) inflammatory and immunomodulatory diseases. Protagonist Pty Limited (“Protagonist Australia”) is a wholly-owned subsidiary of the Company and is located in Brisbane, Queensland, Australia.

Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Chief Executive Officer, the Company’s chief operating decision maker, in deciding how to allocate resources and assessing performance. The Company operates and manages its business as one operating segment. The Company’s Chief Executive Officer reviews financial information on an aggregate basis for the purposes of allocating and evaluating financial performance.

Substantially all of the Company’s long-lived assets are maintained in the United States.

Liquidity

As of December 31, 2022, the Company had cash, cash equivalents and marketable securities of $237.4 million. The Company has incurred net losses from operations since inception and had an accumulated deficit of $536.8 million as of December 31, 2022. The Company’s ultimate success depends upon the outcome of its research and development and collaboration activities. The Company expects to incur additional losses in the future and anticipates the need to raise additional capital to continue to execute its long-range business plan. Since the Company’s initial public offering in August 2016, it has financed its operations primarily through proceeds from offerings of common stock and payments received under license and collaboration agreements.

Risks and Uncertainties

The Company is subject to risks and uncertainties as a result of the prolonged nature of the COVID-19 pandemic and emergent variants with increased transmissibility, even in those who are fully vaccinated. The future impact on the Company’s activities will depend on a number of factors, including, but not limited to, the scope and magnitude of any resurgences in the outbreak and the spread of COVID-19 variants, the timing, extent, effectiveness and durability of COVID-19 vaccine programs or other treatments; and new travel and other restrictions and public health measures. The Company has experienced delays in its existing and planned clinical trials due to worldwide impacts related to the pandemic. The Company’s future results of operations and liquidity could be adversely impacted by further delays in existing and planned clinical trials, continued difficulty in recruiting patients for these clinical trials, delays in manufacturing and collaboration activities, supply chain disruptions, and the ongoing impact on its operating activities and employees. In addition, a recession or market correction related to or amplified by COVID-19 could materially affect the Company’s business.

The Company is currently operating in a period of economic uncertainty and capital markets disruption, which has been impacted by domestic and global monetary and fiscal policy, geopolitical instability, including an ongoing military conflict between Russia and Ukraine and the rising tensions between China and Taiwan, a recessionary environment and historically high domestic and global inflation. In particular, the conflict in Ukraine has exacerbated market disruptions, including significant volatility in commodity prices, as well as supply chain interruptions, and has contributed to record inflation globally. The U.S. Federal Reserve and other central banks may be unable to contain inflation through more restrictive monetary policy, and inflation may increase or continue for a prolonged period of time. Inflationary factors, such as increases in the cost of clinical supplies, interest rates, overhead costs and transportation costs may adversely affect the Company’s operating results. The Company continues to monitor these events and the potential impact on its business. Although the Company does not believe that inflation has had a material impact on its financial position or

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results of operations to date, it may be adversely affected in the future due to domestic and global monetary and fiscal policy, supply chain constraints, consequences associated with COVID-19 and the ongoing conflict between Russia and Ukraine and other factors, and such factors may lead to increases in the cost of manufacturing for and initiation of studies in the Company’s product candidates.

Note 2. Summary of Significant Accounting Policies

Basis of Presentation and Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Protagonist Australia, and have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”). All intercompany balances and transactions have been eliminated upon consolidation.

The financial statements of Protagonist Australia use the Australian dollar as the functional currency since the majority of expense transactions occur in such currency. Gains and losses from foreign currency transactions were not material for all periods presented. The re-measurement from Australian dollar to U.S. dollars is outlined below:

Foreign currency translation gains and losses are reported as a component of stockholders’ equity in accumulated other comprehensive loss on the consolidated balance sheets.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, accruals for research and development activities, stock-based compensation, income taxes, marketable securities and leases. Estimates related to revenue recognition include actual costs incurred versus total estimated costs of the Company’s deliverables to determine percentage of completion in addition to the application and estimates of potential revenue constraints in the determination of the transaction price under its license and collaboration agreements. Management bases these estimates on historical and anticipated results, trends and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to forecasted amounts and future events.

Due to the prolonged nature of the COVID-19 pandemic, military conflict between Ukraine and Russia, rising tensions between China and Taiwan and inflationary pressures, there has been uncertainty and disruption in the global economy and financial markets. The Company has taken into consideration any known impacts in its accounting estimates to date and is not aware of any additional specific events or circumstances that would require any additional updates to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of the filing date of this Annual Report on Form 10-K. These estimates may change as new events occur and additional information is obtained.

Actual results could differ materially from these estimates under different assumptions or conditions.

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Concentrations of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and marketable securities. Substantially all of the Company’s cash is held by two financial institutions that management believes are of high credit quality. Such deposits may, at times, exceed federally insured limits. The primary focus of the Company’s investment strategy is to preserve capital and to meet liquidity requirements. The Company’s cash equivalents and marketable securities are managed by external managers within the guidelines of the Company’s investment policy. The Company’s investment policy addresses the level of credit exposure by limiting concentration in any one corporate issuer and establishing a minimum allowable credit rating. To manage its credit risk exposure, the Company maintains its U.S. portfolio of cash equivalents and marketable securities in fixed income securities denominated and payable in U.S. dollars. Permissible investments of fixed income securities include obligations of the U.S. government and its agencies, money market instruments including commercial paper and negotiable certificates of deposit, and highly rated corporate debt obligations and money market funds, and highly rated supranational and sovereign government securities.

Cash Equivalents

Cash equivalents that are readily convertible to cash are stated at cost, which approximates fair value. The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.

Restricted Cash

Restricted cash consists primarily of cash balances held as security in connection with a letter of credit related to the Company’s facility lease entered into in March 2017, as subsequently amended. The letter of credit balance decreased from $0.5 million at December 31, 2020 to $0.2 million at December 31, 2021 and 2022 pursuant to the terms of the facility lease.

Cash as Reported in Consolidated Statements of Cash Flows

Cash as reported in the consolidated statements of cash flows includes the aggregate amounts of cash and cash equivalents and the restricted cash as presented on the consolidated balance sheets.

Cash as reported in the consolidated statements of cash flows consisted of (in thousands):

December 31,

Restricted cash - current — — 10

Restricted cash - noncurrent 225 225 450

Marketable Securities

All marketable securities have been classified as “available-for-sale” and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its marketable securities at the time of purchase and reevaluates such designation as of each balance sheet date. Short-term marketable securities have maturities greater than three months but not longer than 365 days as of the balance sheet date. Long-term marketable securities have maturities of 365 days or longer as of the balance sheet date. Unrealized gains and losses are excluded from earnings and are reported as a component of comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest income. The cost of securities sold is based on the specific-identification method. Interest on marketable securities is included in interest income.

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Fair Value of Financial Instruments

Fair value accounting is applied to all financial assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis (at least annually). The carrying amount of the Company’s financial instruments, including cash equivalents, receivables from its collaboration partner, accounts payable, payables to its collaboration partner and accrued expenses and other payables approximate fair value due to their short-term maturities. See Note 4. to the Consolidated Financial Statements for additional information regarding the fair value of the Company’s other financial assets and liabilities.

Property and Equipment

Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, ranging from three to five years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives of the assets. Maintenance and repairs are charged to expense as incurred. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in operations in the period realized.

Leases

The Company determines if an arrangement is a lease at inception. Pursuant to Accounting Standards Codification Topic 842, Leases, (“ASC 842”), operating leases are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, and noncurrent operating lease liabilities on the consolidated balance sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. If the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

The Company records tenant improvement allowances as a reduction to the ROU asset with the impact of the decrease recognized prospectively over the remaining lease term. The leasehold improvements are amortized over the shorter of their useful life or the remaining term of the lease.

Impairment of Long-Lived Assets

The Company reviews long-lived assets, primarily comprised of property, equipment and operating lease ROU assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future net cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the asset. There have been no such impairments of long-lived assets for any of the periods presented.

Comprehensive Loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those from stockholders. The Company’s foreign currency translation and unrealized gains and losses on available-for-sale securities represent the only components of other comprehensive loss that are excluded from reported net loss and that are presented in the consolidated statements of comprehensive loss.

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Income Taxes

The Company uses the asset and liability method to account for income taxes in accordance with the authoritative guidance for income taxes. Under this method, deferred tax assets and liabilities are determined based on future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, and tax loss and credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized.

The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than a 50% likelihood of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company records interest and penalties related to unrecognized tax benefits in income tax expense. To date, there have been no interest or penalties recorded in relation to unrecognized tax benefits.

Revenue Recognition

Under Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”), the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, the Company assesses the goods or services promised within each contract, determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligations when (or as) the performance obligations are satisfied. The Company constrains its estimate of the transaction price up to the amount (the “variable consideration constraint”) that a significant reversal of recognized revenue is not probable.

Licenses of intellectual property: If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in an arrangement, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring proportional performance for purposes of recognizing revenue from non-refundable, upfront fees. The Company evaluates the measure of proportional performance each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

Milestone payments: At the inception of each arrangement or amendment that includes development, regulatory or commercial milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. ASC 606 suggests two alternatives to use when estimating the amount of variable consideration: the expected value method and the most likely amount method. Under the expected value method, an entity considers the sum of probability-weighted amounts in a range of possible consideration amounts. Under the most likely amount method, an entity considers the single most likely amount in a range of possible consideration amounts. Whichever method used should be consistently applied throughout the life of the contract; however, it is not necessary for the Company to use the same approach for all contracts. The Company expects to use the most likely amount method for development and regulatory milestone payments. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone

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payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. If there is more than one performance obligation, the transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis. The Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability or achievement of each such milestone and any related constraint, and if necessary, adjusts its estimates of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment.

Any potential milestone payments that the Company determines are not associated with performance obligations as defined under the contract are excluded from the transaction price and are recognized as the triggering event occurs.

Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, where the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Upfront payments and fees are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional. Amounts payable to the Company and not yet billed to the collaboration partner are recorded as contract assets. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less.

Contracts may be amended to account for changes in contract specifications and requirements. Contract modifications exist when the amendment either creates new, or changes existing, enforceable rights and obligations. When contract modifications create new performance obligations and the increase in consideration approximates the standalone selling price for goods and services related to such new performance obligations, as adjusted for specific facts and circumstances of the contract, the modification is considered to be a separate contract. If a contract modification is not accounted for as a separate contract, the Company accounts for the promised goods or services not yet transferred at the date of the contract modification (the remaining promised goods or services) prospectively, as if it were a termination of the existing contract and the creation of a new contract, if the remaining goods or services are distinct from the goods or services transferred on or before the date of the contract modification. The Company accounts for a contract modification as if it were a part of the existing contract if the remaining goods or services are not distinct and, therefore, form part of a single performance obligation that is partially satisfied at the date of the contract modification. In such case the effect that the contract modification has on the transaction price, and on the entity’s measure of progress toward complete satisfaction of the performance obligation, is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) at the date of the contract modification (the adjustment to revenue is made on a cumulative catch-up basis).

Research and Development Costs

Research and development costs (“R&D”) are expensed as incurred, unless there is an alternate future use in other research and development projects or otherwise. Research and development costs include salaries and benefits, stock-based compensation expense, laboratory supplies and facility-related overhead, outside contracted services, including clinical trial costs, manufacturing and process development costs for both clinical and pre-clinical materials, research costs, development milestone payments under license and collaboration agreements, and other consulting services.

The Company accrues for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of pre-clinical studies and clinical trials and contract manufacturing activities. The

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Company records the estimated costs of research and development activities based upon the estimated services provided but not yet invoiced and includes these costs in accrued expenses and other payables in the consolidated balance sheets and within research and development expense in the consolidated statements of operations. The Company accrues for these costs based on various factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued liabilities and actual costs incurred. However, the status and timing of actual services performed, the number of patients enrolled, the rate of patient enrollment and the number and location of sites activated may vary from the Company’s estimate and may result in adjustments to research and development expenses in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations.

Research and Development Tax Incentive

The Company is eligible under the AusIndustry research and development tax incentive program to obtain either a refundable cash tax incentive or a taxable credit in the form of a non-cash tax incentive from the Australian Taxation Office (“ATO”). The refundable cash tax incentive is available to the Company on the basis of specific criteria with which the Company must comply. Specifically, the Company must have annual turnover of less than AUD 20.0 million and cannot be controlled by income tax exempt entities. The refundable cash tax incentive is recognized as a reduction to research and development expense when the right to receive has been attained and funds are considered to be collectible. The Company may alternatively be eligible for a taxable credit in the form of a non-cash tax incentive in years when the annual turnover exceeds the limit. The Company evaluates its eligibility under tax incentive programs as of each balance sheet date and makes accrual and related adjustments based on the most current and relevant data available.

Stock-based Compensation

The Company measures its stock-based awards made to its equity plan participants based on the estimated fair values of the awards as of the grant date. For stock option awards, the Company uses the Black-Scholes option-pricing model to estimate fair values. For restricted stock unit awards, the estimated fair value is generally the fair market value of the underlying stock on the grant date. Stock-based compensation expense is recognized over the requisite service period and is based on the value of the portion of stock-based payment awards that is ultimately expected to vest. The Company recognizes forfeitures of stock-based awards as they occur.

The Company has granted performance share units (“PSUs”) to certain executives of the Company. Stock-based compensation expense associated with PSUs is based on the fair value of the Company’s common stock on the grant date, which equals the closing price of the Company’s common stock on the grant date. The Company recognizes compensation expense over the vesting periods of the awards that are ultimately expected to vest when the achievement of the related performance obligation becomes probable.

If stock-based awards are granted in contemplation of or shortly before a planned release of material nonpublic information, and such information is expected to result in a material increase in the Company’s share price, the Company considers whether an adjustment to the observable market price is required when estimating fair values.

Net Loss per Share

Basic net loss per share is calculated by dividing the Company’s net loss by the weighted average number of shares of common stock and Exchange Warrants (as defined in Note 12. Stockholders’ Equity below) outstanding during the period, without consideration of potentially dilutive securities. In accordance with Accounting Standards Codification Topic 260, Earnings Per Share, outstanding Exchange Warrants are included in the computation of basic net loss per share because the exercise price is negligible, and they are fully vested and exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share for all periods presented since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company in each period. See Note 12. Stockholders’ Equity for additional information regarding the Exchange Warrants.

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Recently Issued Accounting Pronouncements Not Yet Adopted as of December 31, 2022

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), which is intended to provide more useful information about expected credit losses on financial assets held by a reporting entity at each reporting date. The new standard replaces the existing incurred loss impairment methodology with a methodology that requires consideration of a broader range of reasonable and supportable forward-looking information to estimate all expected credit losses. This guidance was originally effective for fiscal years and interim periods beginning after December 15, 2019, with early adoption permitted for fiscal years and interim periods beginning after December 15, 2018. In November 2019, the FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates, which amended the mandatory effective date of ASU No. 2016-13 for smaller reporting companies. Based on the Company’s status as a smaller reporting company as of November 15, 2019, ASU 2016-13 is effective for the Company for fiscal years and interim periods beginning after December 15, 2022. The Company does not expect the adoption of this new guidance to have a material impact on its consolidated financial statements and related disclosures.

Note 3. License and Collaboration Agreement

Agreement Terms

On July 27, 2021, the Company entered into an Amended and Restated License and Collaboration Agreement (the “Restated Agreement”) with Janssen Biotech, Inc., a Pennsylvania corporation (“Janssen”) which amended and restated the License and Collaboration Agreement, effective July 13, 2017, by and between the Company (the “Original Agreement”), as amended by the first amendment, effective May 7, 2019 (the “First Amendment”). Janssen is a related party to the Company as Johnson & Johnson Innovation - JJDC, Inc., a significant stockholder of the Company, and Janssen are both subsidiaries of Johnson & Johnson. Upon the effectiveness of the Original Agreement, the Company received a non-refundable, upfront cash payment of $50.0 million from Janssen. Upon the effectiveness of the First Amendment, the Company received a $25.0 million payment from Janssen in 2019. The Company received a $5.0 million payment triggered by the successful nomination of a second-generation oral Interleukin (“IL”)-23 receptor antagonist development compound (“second-generation compound”) during the first quarter of 2020 and a $7.5 million payment triggered by the completion of data collection activities for the first Phase 1 clinical trial of a second-generation compound during the fourth quarter of 2021. The Company received a $25.0 million milestone payment in connection with the dosing of the third patient in the first Phase 2 clinical trial for a second-generation compound during the second quarter of 2022.

The Restated Agreement relates to the development, manufacture and commercialization of oral IL-23 receptor antagonist drug candidates. The candidates nominated for initial development pursuant to the Restated Agreement included PTG-200 (JNJ-67864238), PN-232 (JNJ-75105186) and JNJ-2113 (JNJ-77242113) (formerly known as PN- 235). PTG-200 is an oral IL-23 receptor antagonist that was in Phase 2a development for the treatment of Crohn’s disease (“CD”). During the fourth quarter of 2021, following a pre-specified interim analysis criteria, a portfolio decision was made by Janssen to stop further development of both PTG-200 and PN-232 in favor of advancing JNJ-2113, based on its superior potency and overall pharmacokinetic and pharmacodynamic profile. Janssen is primarily responsible for the conduct of all future trials, including current and anticipated Phase 2 trials, and the Company is primarily responsible for the conduct of the second-generation Phase 1 trials.

Pursuant to the Restated Agreement, the parties:

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The Restated Agreement enables Janssen to develop collaboration compounds for multiple indications. Under the Restated Agreement, Janssen is required to use commercially reasonable efforts to develop at least one collaboration compound for at least two indications.

The Company’s development cost obligations in the Original Agreement for the period following the effective date of the Original Agreement were as follows: (a) up to $20.0 million of costs related to up to three Phase 1 trials of second-generation compounds; (b) up to $20.0 million of costs related to Phase 2a and 2b costs for PTG-200 (i.e., 20% of the first $100.0 million in costs); and (c) up to $25.0 million in costs related to up to two Phase 2 trials evaluating second-generation compounds.

The Company’s development cost obligations under the Restated Agreement are as follows: (a) the Company funded 20% of the costs related to the Phase 2a trial evaluating PTG-200 for the treatment of CD (subject to a $20.0 million cap); (b) the Company was responsible for 50% of agreed-upon costs related to the Phase 1 trial evaluating JNJ- 2113 incurred through January 4, 2021; and (c) the Company was responsible for 100% of agreed-upon costs related to the Phase 1 trial evaluating PN-232.

Certain of the Company’s previous development cost obligations under the Original Agreement were limited or eliminated as follows: (a) the Company’s previous $25.0 million obligation for 20% of costs related to Phase 2 trials for second-generation products was eliminated; (b) the Company’s previous $5.0 million obligation for 50% of the costs of a potential third Phase 1 trial evaluating a second-generation compound was eliminated; and (c) the Company had no obligation to fund any portion of any Phase 2b or other trial evaluating PTG-200 beyond the Phase 2a trial in CD.

One milestone for second-generation Phase 2 development was reduced from $50.0 million to $25.0 million in the Restated Agreement; otherwise, the various milestone payment amounts in the Restated Agreement remain substantially the same as in the Original Agreement. To reflect parallel development of multiple indications in the IL-23 pathway, milestone payments under the Restated Agreement generally correspond to the achievement of specified milestones in: (a) any initial indication (rather than CD, as in the Original Agreement); (b) any second indication (rather than ulcerative colitis (“UC”), as in the Original Agreement); and (c) any third indication. With respect to second-generation compounds, milestone payments for second and third indications may be triggered by any second-generation compound (i.e., not necessarily the second-generation compound that triggered the initial payment for any indication, or the payment for a second indication). In addition, the opt-in payments contemplated by the Original Agreement related to the scope of Janssen’s license rights have been converted into development milestones in the Restated Agreement.

Upcoming potential development milestones for second-generation compounds include:

Development milestones for PTG-200 were unchanged under the Restated Amendment, except that milestone achievement is generally no longer indication-specific.

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Pursuant to the Restated Agreement, the Company remains eligible to receive tiered royalties on net product sales at percentages ranging from mid-single digits to ten percent. The sales milestone payments in the Original Agreement also remain the same in the Restated Agreement.

Pursuant to both the Original and Restated Agreements, payments to the Company for research and development services are generally billed and collected as services are performed or assets are delivered, including research activities and Phase 1 and Phase 2 development activities. Janssen bills the Company for its share of the PTG-200 Phase 2a development costs as expenses are incurred by Janssen. Milestone payments are received after the related milestones are achieved.

Janssen retains exclusive, worldwide rights to develop and commercialize IL-23 receptor antagonist compounds derived from the research collaboration conducted under the Original Agreement, or Janssen’s further research under the Restated Agreement. Any further research and development will be conducted by Janssen. The Company will have the right to co-detail (for CD and UC indications) up to two of the IL-23 receptor antagonist compounds under the collaboration in the U.S. market.

The Restated Agreement remains in effect until the royalty obligations cease following patent and regulatory expiry, unless terminated earlier. Upon a termination of the Restated Agreement, all rights revert back to the Company, and in certain circumstances, if such termination occurs during ongoing clinical trials, Janssen would, if requested, provide certain financial and operational support to the Company for the completion of such trials.

Revenue Recognition

The Restated Agreement contains a single performance obligation for the development license; Phase 1 development services for PTG-200, PN-232 and JNJ-2113 (formerly known as PN-235); the Company’s services associated with Phase 2a development for PTG-200 in CD; the initial year of second-generation compound research services; and all other such services that the Company may perform at the request of Janssen to support the development of PTG-200 through Phase 2a and PN-232 and JNJ-2113 through Phase 1. Under the Restated Agreement, development services performed by the Company for PTG-200 beyond Phase 2a and PN-232 and JNJ-2113 beyond Phase 1 are no longer required.

The Company determined that the license was not distinct from the revised development services within the context of the agreement because the revised development services did not change the utility of the intellectual property. The Company also concluded that the remaining development services are not distinct from the partially delivered combined promise comprised under the agreement prior to the Restated Agreement of the development license and PTG-200, PN- 232 and JNJ-2113 services, including compound supply and other services. Therefore, the Restated Agreement is treated as if it were part of the Original Agreement. The Restated Agreement was accounted for as if it were a modification of services under the Original Agreement by applying a cumulative catch-up adjustment to revenue. As of the effective date of the Restated Agreement, the Company calculated the adjusted cumulative revenue under the Restated Agreement with primary updates to the transaction price, including the release of and update of prior constraints and fewer remaining services to be provided, resulting in a cumulative adjustment that increased revenue by $8.0 million for the year ended December 31, 2021.

The contract duration is defined as the period in which parties to the contract have present enforceable rights and obligations. For revenue recognition purposes, the duration of the Restated Agreement for the identified single initial performance obligations began on the Original Agreement effective date of July 13, 2017 and ended upon the completion of Phase 1 clinical trials for PN-232 and JNJ-2113. Final activities related to these trials were completed as of June 30, 2022.

The Company uses the most likely amount method to estimate variable consideration included in the transaction price. Variable consideration after the effective date of the Restated Agreement consisted of future milestone payments and cost sharing payments for agreed-upon services offset by development cost reimbursable to Janssen. Cost sharing payments from Janssen relate to the agreed-upon services for development activities that the Company performs within the duration of the contract and are included in the transaction price at the Company’s share of estimated budgeted costs

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for these activities, including primarily internal full-time equivalent effort and third-party contract costs. Cost sharing payments to Janssen relate to agreed-upon services for activities that Janssen performs within the duration of the contract are not a distinct service that Janssen transfers to the Company. Therefore, the consideration payable to Janssen is accounted for as a reduction in the transaction price.

The transaction price of the initial performance obligation under the Restated Agreement was $131.7 million as of December 31, 2022, an increase of $25.2 million from the transaction price of $106.5 million at December 31, 2021 under the Restated Agreement and an increase of $33.1 million from the transaction price of $98.6 million at December 31, 2020 under the Original Agreement. In order to determine the transaction price, the Company evaluates all payments to be received during the duration of the contract, net of development costs reimbursement expected to be payable to Janssen. The transaction price as of December 31, 2022 includes $112.5 million of nonrefundable payments received to date, $17.9 million of reimbursement from Janssen for services performed for IL-23 receptor antagonist compound research and other services, and variable consideration consisting of $8.2 million of development cost reimbursement from Janssen, partially offset by $6.9 million of net cost reimbursement due to Janssen for services performed. The Company concluded that the variable consideration constraint is appropriately reflected in the transaction price as of December 31, 2022, and that the achievement of future milestones is subject to additional development and/or regulatory uncertainty and therefore it is not probable at December 31, 2022 that a material reversal of such revenues will not occur. Janssen also opted in for certain additional services to be performed by the Company that were outside the initial performance obligation. Revenue for these additional services was recognized as these services were performed.

The Company utilized a cost-based input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. In applying the cost-based input method of revenue recognition, the Company used actual costs incurred relative to expected costs to fulfill the combined performance obligation. These costs consist primarily of internal full-time equivalent effort and third-party contract costs. Revenue was recognized based on actual costs incurred as a percentage of total estimated costs as the Company completed its performance obligations. A cost-based input method of revenue recognition requires management to make estimates of costs to complete the Company’s performance obligations. The Company believes this is the best measure of progress because other measures do not reflect how the Company transfers its performance obligation to Janssen.

For the year ended December 31, 2022, the Company recognized $26.6 million of license and collaboration revenue, which was primarily related to the transaction price under the Restated Agreement recognized based on proportional performance. The Company completed its performance obligation under the collaboration as of June 30 , 2022.

For the year ended December 31, 2021, the Company recognized $27.4 million of license and collaboration revenue. This amount included a cumulative catch-up adjustment increasing license and collaboration revenue by $8.0 million, and $18.6 million of license and collaboration revenue based on proportional performance following the Restated Agreement. In addition, the Company recorded $0.8 million of revenue related to additional services provided by the Company under the Restated Agreement.

For the year ended December 31, 2020, the Company recognized $28.6 million of license and collaboration revenue. This amount included $27.1 million of the transaction price based on proportional performance and an update in forecasted amounts for future services remaining to be performed and recognized under the Original Agreement. In addition, the Company recorded $1.5 million of revenue for the year ended December 31, 2020 related to additional services provided by the Company under the Original Agreement.

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The following tables present changes in the Company’s contract assets and liabilities during the periods presented (in thousands):

Balance at Balance at

Beginning of End of

Year Ended December 31, 2022 Period Additions Deductions Period

Contract assets:

Contract liabilities:

Deferred revenue - related party $ 1,601 $ 25,757 $ (27,358) $ —

Balance at Balance at

Beginning of End of

Year Ended December 31, 2021 Period Additions Deductions Period

Contract assets:

Contract liabilities:

During the year ended December 31, 2022, the Company recognized revenue of $0.9 million from amounts included in the deferred revenue balance at the beginning of the year. During the year ended December 31, 2021, the Company recognized revenue of $2.8 million from amounts included in the deferred revenue balance at the beginning of the year. During the year ended December 31, 2020, the Company recognized $14.1 million from amounts included in the deferred revenue balance at the beginning of the year. None of the costs to obtain or fulfill the contract were capitalized.

Note 4. Fair Value Measurements

Financial assets and liabilities are recorded at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows:

Level 1—Inputs are unadjusted 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) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.

Level 3—Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

In determining fair value, the Company utilizes quoted market prices, broker or dealer quotations, or valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible and considers counterparty credit risk in its assessment of fair value.

Table of Contents

PTGX US Equity

PTGX · 10-K · period ended 2022-12-31

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

PTGX US Equity☆

PTGX · 10-K · period ended 2022-12-31

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

PTGX US Equity