PTGX 10-K & 10-Q changes, risk factors and insider trading

We are a biopharmaceutical company with a somewhat limited operating history as a publicly traded company. Biopharmaceutical product development is a highly speculative undertaking and involves a substantial degree of uncertainty. Our operations to date have been limited to developing our technology, undertaking pre-clinical studies and clinical trials of our pipeline candidates andcandidates, conducting research to identify additional product candidates and entering into partnerships with collaborators for certain of our product candidates. We have not yet successfully developed an approved product or generated revenue from product sales or successfully conductedcompleted a pivotal registration trial for one of our product candidates. Consequently, the ability to accurately assess our future operating results or business prospects is significantly more limited than if we had a longer operating history or approved products on the market.

We expect that our financial condition and operating results will fluctuate significantly from period to period due to a variety of factors, many of which are beyond our control, including the success of our programs, decisions by regulatory bodies, actions taken by competitors or current or future licensees or collaborative partners,collaborators, market and macroeconomic conditions and other factors identified in these risk factors. Accordingly, the likelihood of our success must be evaluated in light of many potential challenges and variables associated with a clinical-stage biopharmaceutical company, many of which are outside of our control, and past results, including operating or financial results, should not be relied on as an indication of future results.

In addition to our planned pre-clinical studies and clinical trials, we will be required to complete one or more large scale, well-controlled clinical trials to demonstrate substantial evidence of efficacy and safety for each product candidate we intend to commercialize. Further, given the patient populations for which we are developing therapeutics, we expect to have to evaluate long-term exposure to establish the safety of our therapeutics in a chronic-dose setting. We have not yet completed a Phase 3 clinical trial or submitted an NDA. As a result, we have no corporate history or track record of successfully completing these phases of the development cycle. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy traits despite having progressed through pre-clinical studies and initial clinical trials. Clinical trial failures may result from a multitude of factors including, but not limited to, flaws in trial design, dose selection, placebo effect, patient enrollment criteria and failure to demonstrate favorable safety and/or efficacy traits of the product candidate. Based upon negative or inconclusive results, we may decide, or regulators may require us, to conduct additional clinical trials or pre-clinical studies. In addition, success in clinical trials in a particular indication does not ensure that a product candidate will be successful in other indications. Similarly, approval of a product candidate in a particular indication does not ensure that the product candidate will be successful in other indications currently being studied.

We may experience delays in ongoing clinical trials, and we do not know whether planned clinical trials will begin on time, need to be redesigned, enroll patients on time or be completed on schedule, if at all. For example, we initially experienced slower than expected patient enrollment in VERIFY, a global Phase 3 clinical trial of rusfertide in PV. Clinical trials can be delayed for a variety of reasons, including if a clinical trial is modified, suspended or terminated by us. For example, in keeping with our organizational prioritization of rusfertide in PV, plans to initiate trials of rusfertide in other indications have been paused. Clinical trials can also be delayed by the institutional review boards or ethics committees of the institutions in which such clinical trials are being conducted, by a Data Safety Monitoring Board, for such trialtrial, or by the FDA or other regulatory authorities. Such authorities may impose a modification, suspension or termination due to a number of factors. For example, our rusfertide clinical studies were subject to a three-week clinical hold by the FDA in September 2021.

In addition, there are a significant number of global clinical trials in inflammatory and immunology disorders, hematologic disorders and metabolic disorders that are currently ongoing, especially in Phases 2 and 3, making it highly competitive and challenging to recruit subjects. Other companies targeting the same patient populations as our clinical trials for such medicines may make it more difficult for us to complete enrollment in our clinical trials. Furthermore, any negative results we may report in clinical trials of our product candidate may make it difficult or impossible to recruit and retain patients in other ongoing or subsequent clinical trials of that same product candidate. Delays or failures in planned patient enrollment or retention may result in increased costs, program delays or both.

Our proprietary peptidetechnology platform may not result in any products of commercial value.

We have developed a proprietary peptide technology platform to enable the identification, testing, design and development of new product candidates. Our peptide platform may not yield additional product candidates that enter clinical development and, ultimately, become commercially valuable. Although we expect to continue to enhance the capabilities of our platform by developing and integrating existing and new research technologies, our enhancement and development efforts may not succeed. As a result, we may not be able to advance our drug discovery capabilities as quickly as we expect or identify as many potential drug candidates as we desire.

If undesirable side effects or adverse events are caused by our product candidates or by other companies’ similar approved drugs or product candidates, then we may elect to, or be required by an independent data monitoring committee or regulatory authorities to, delay or halt our clinical trials. If such side effects or adverse events are sufficiently severe or prevalent, the FDA or comparable foreign regulatory authorities could order us to suspend or cease altogether further development of our product candidates. Even if our product candidates are approved, side effects or adverse events could result in significant delay in or denial of,of regulatory approval, restrictive labeling, or potential product liability claims. Moreover, for our product candidates that are in development for indications for which injectable antibody drugs have been approved, clinical trials for those product candidates may need to show a risk/benefit profile that is competitive with those existing products in order to obtain regulatory approval or, if approved, a product label that is favorable for commercialization.

Because we have limited financial and managerial resources, we have historically focused on research programs and product candidates mainly onfor the development of rusfertide and the product candidates subject to our JNJ collaboration. We have an ongoing commitment to optimize and focus resources towardon our rusfertidedrug programdiscovery inand PV.development programs addressing biologically and commercially validated targets. In addition, in keeping with our organizational prioritization of rusfertide in PV, plans to initiate trials of rusfertide in additional disease indications have been paused. As a result, we may forego or delay the pursuit of opportunities with other product candidates or for other indications that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaboration partnerships, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate.

We have incurred a cumulative net loss since our inception and anticipate that we may incur significant losses in the future. We have never generated any revenue from product sales and may never be profitable.sales.

We have incurred a cumulative net operating loss since inception and may continue to incur operating losses in the future. As of December 31, 2024,2025, we had an accumulated deficit of $340.5$470.7 million. We expect to continue to incur significant research, development and other expenses related to our ongoing operations and product development. As a result, we expect tomay continue to incur losses in the future as we continue our development of, and seek regulatory approvals for, our product candidates.

WeIn do not anticipate generating revenue from sales of products for a number of years,addition, if ever, and we have not yet successfully completed registrational or pivotal clinical trials for our product candidates. If any of our product candidates fail in clinical trials or do not gain regulatory approval or fail to achieve market acceptance, we may never become profitable. Revenue we generate from our collaborations with JNJ, Takeda, and any future collaboration arrangementsarrangements, if any, may not be sufficient to sustain our operations. Failure to become and remain profitable may adversely affect the market price of our common stock and our ability to raise capital and continue operations.

Our operations have consumed substantial amounts of cash since inception. Developing pharmaceutical product candidates, including conducting pre-clinical studies and clinical trials, is expensive. We may require additional future capital in order to complete clinical development and, if we are successful, to commercialize any of our current product candidates. Further, in the event that the JNJ License and Collaboration Agreement or the Takeda Collaboration Agreement is terminated, we may not receive any additional fees or milestone payments under these agreements. In addition, if either JNJ or Takeda fail to successfully commercialize Icotyde or rusfertide, respectively, if approved, we would not receive any royalty payments under these agreements. Absent the funding support obtained under these agreements, our further development of the collaboration product candidates and our drug discovery and development programs would require significant additional capital from us, or the establishment of alternative collaborations with third parties, which may not be possible.

RaisingIf we require additional capitalcapital, there may causebe dilution to our existing stockholders, restrict our operations may be restricted, or requirewe usmay be required to relinquish rights to our product candidates or technologies.

We have in the past and may in the future seek additional funding through a combination of equity offerings, including the use of the 2022 ATM Facility, debt financings, collaborations and/or licensing arrangements. Additional funding may not be available to us on acceptable terms, or at all. Our ability to raise additional capital may be adversely impacted by adverse economic conditions and market volatility, including as a result of public health crises; changes in trade policies, including tariffs or other trade restrictions or the threat of such actions; political instability, including the ongoing conflict between Russia and Ukraine and in the Middle East and rising tensions between China and Taiwan; and high interest rates. The incurrence of indebtedness and/or the issuance of certain equity securities could result in fixed payment obligations and could also result in certain additional restrictive covenants, such as limitations on our ability to incur debt and/or issue additional equity, limitations on our ability to acquire or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. In addition, the issuance of additional equity securities by us, or the possibility of such issuance, may cause the market price of our common stock to decline. In the event that we enter into additional collaborations and/or licensing arrangements in order to raise capital, we may be required to accept unfavorable terms, including relinquishing or licensing to a third party on unfavorable terms our rights to our proprietary technology platform or product candidates. To the extent that we raise additional capital through the sale of equity securities, your ownership interest will be diluted, and the terms may include liquidation or other preferences that adversely affect your rights as a stockholder. If we issue common stock or securities convertible into common stock, our common stockholders will experience additional dilution and, as a result, our stock price may decline.

If JNJ does not elect to continue the development of icotrokinra,or successfully commercialize Icotyde, or if Takeda does not elect to develop and commercialize rusfertide, our business and business prospects would be adversely affected.

Icotrokinra,Icotyde, the product candidate in development pursuant to ourthe JNJ collaboration,License and Collaboration Agreement, and rusfertide, the product candidate in development pursuant to the Takeda Collaboration Agreement, may prove to have undesirable or unintended side effects or other characteristics adversely affecting itstheir safety, efficacy or cost effectiveness that could prevent or limit itstheir approval for marketing and successful commercial use, or that could delay or prevent the commencement and/or completion of clinical trials.

Under the terms of the JNJ License and Collaboration Agreement, JNJ may terminate the agreement for convenience and without cause on written notice of a certain period. In addition, prior to any termination of the agreement, JNJ will generally have control over the further clinical development of icotrokinraIcotyde and any other licensed compounds.compounds and commercialization, if Icotyde is approved. JNJ’s decisions with respect to such development and commercialization will affect the timing and availability of potential future payments under the agreement, if any. For example, during the fourth quarter of 2021, a decision was made by JNJ to stop further development of both PTG-200 and PN-232 in favor of icotrokinra.

Under the terms of the Takeda Collaboration Agreement, Takeda may terminate the agreement for convenience in its entirety or as to a major region by providing advance written notice to us. If the JNJ License and Collaboration Agreement or the Takeda Collaboration Agreement isare terminated early, or if JNJ’s or Takeda’s development activities are terminated early or suspended for an extended period of time, or are otherwise unsuccessful, or if JNJ’s or Takeda’s commercialization efforts are deprioritized or unsuccessful, our businessbusiness, financial condition and business prospects would be materially and adversely affected.

We are subject to the risk of possible disagreements with JNJ regarding the development or commercialization of icotrokinraIcotyde, if approved, or other matters under the JNJ License and Collaboration Agreement and with Takeda regarding the development or commercialization of rusfertiderusfertide, if approved, or other matters under the Takeda Collaboration Agreement, such as the interpretation of such agreementagreements, milestones or royalty payments or ownership of proprietary rights. Also, because the period of collaborative development under the agreement has ended, JNJ has sole decision-making authority for product candidates resulting from the collaboration, which could lead to disputes with JNJ. Disagreements with JNJ or Takeda could lead to litigation or arbitration, which would be expensive and would be time-consuming for our management and employees. If agreements are not settled amicably or in our favor, our business, financial condition and prospects would be materially and adversely affected.

Other than our collaboration with JNJ under the JNJ License and Collaboration Agreement and our collaboration with Takeda under the Takeda Collaboration Agreement, we have no active collaborations for any of our product candidates. Our collaborations with JNJ and Takeda and any future collaboration arrangements may not ultimately be successful, which could have a negativematerial impactand adverse effect on our business, results of operations, financial condition and growth prospects. We do not maintain significant rights or control of future development and commercialization activities under our collaboration with JNJ, or in ex-U.S. territories under our collaboration with Takeda. This could lead to potential disputes in the future over the terms of the collaborations and the respective rights of the parties, and these risks and uncertainties could be present with respect to our potential future collaborations as well.

We also rely on our contract manufacturers to purchase from third-party suppliers the materials necessary to produce our product candidates for our clinical trials. There are a limited number of suppliers for raw materials that our vendors use to manufacture our drugs and there may be a need to assess alternate suppliers to prevent a possible disruption of the manufacture of the materials necessary to produce our product candidates for our clinical trials, and if approved, for commercial sale. Moreover, we currently do not have any agreements for the commercial production of these raw materials. Additionally, the United States and other countries have imposed and may continue to impose new trade restrictions and export regulations, including the potential for tariffs applicable to pharmaceutical products and their inputs, which may make access to materials necessary to produce our product candidates more costly or difficult to acquire. Although we generally do not begin a clinical trial unless we believe we have a sufficient supply of a product candidate to complete the clinical trial, any significant delay in the supply of a product candidate, or the raw material components thereof, for an ongoing clinical trial due to the need to replace a contract manufacturer or other third-party manufacturer could considerably delay completion of our clinical trials, product testing and potential regulatory approval of our product candidates.

The regulatory approval processes of the FDA and comparable foreign authorities are lengthy and time consuming, and if we or our collaborators are ultimately unable to obtain regulatory approval for our product candidates, our business will be substantially harmed.

Throughout the world and particularly in the United States, the healthcare system is under significant financial pressure to reduce costs. The price of pharmaceuticals has been a topic of considerable public discussion that could lead to price controls or other price-limiting strategies by payors that have the effect of lowering payment and reimbursement rates for drugs or otherwise making the commercialization of pharmaceuticals less profitable. Many federal and state legislatures have considered, and adopted, healthcare policies intended to curb rising healthcare costs, such as the Inflation Reduction Act of 2022. These cost-containment measures may include, among other measures: requirements for pharmaceutical companies to negotiate prescription drug prices with government healthcare programs; controls on government-funded reimbursement for drugs; new or increased requirements to pay prescription drug rebates to government healthcare programs, including if drug prices increase at a higher rate than inflation; controls on healthcare providers; challenges to or limits on the pricing of drugs, including pricing controls or limits or prohibitions on reimbursement for specific products through other means; requirements to try less expensive products or generics before a more expensive branded product; and public funding for cost effectiveness research, which may be used by government and private third-party payors to make coverage and payment decisions. In addition, in May 2025, the currrent administration issued an executive order entitled “Delivering Most-Favored-Nation Prescription Drug Pricing to American Patients,” which, among other things, directs the HHS and other agencies to communicate most-favored-nation price targets to pharmaceutical manufacturers to bring prices for U.S. patients in line with comparably developed nations and to facilitate direct-to-consumer purchasing programs. The HHS subsequently issued guidance indicating the MFN target price is the lowest price paid in an Organization for Economic Co-operation and Development country with a GDP per capita of at least 60% of the U.S. GDP per capita. It is currently unclear whether and to what extent these measures will be implemented and what impact any such implementation would have on our business. Further, there can be no assurance that the current administration or future administrations will not pursue different or additional measures that could impact drug pricing in the United States. Political, economic and regulatory developments may further complicate developments in healthcare systems and pharmaceutical drug pricing. These developments could, for example, impact our potential licensing agreements as commercial and collaborative partners may also consider the impact of these pressures on their licensing strategies.

We currently conduct, and intend to continue to conduct, a substantial portion of the clinical trials for our product candidates outside of the United States. If approved, we or our collaborators may commercialize our product candidates abroad. We will thus be subject to the risks of doing business outside of the United States.

We currently conduct, and intend to continue to conduct, a substantial portion of our clinical trials outside of the United States and, if approved, we intend to also market our product candidates outside of the United States.States either directly or through our collaborators. We are thus subject to risks associated with doing business outside of the United States. Our business and financial results in the future could be adversely affected due to a variety of factors associated with conducting development and marketing of our product candidates, if approved, outside of the United States, including varying medical standards and practices, geopolitical risks, uncertainty around intellectual property protection, and regulatory risks, such as compliance with the Foreign Corrupt Practices Act. If we are unable to anticipate and address these risks properly, our business and financial results will be harmed.

We or our collaborators may fail or elect not to commercialize our product candidates, even if approved.

We cannot be sure that, if our clinical trials for any of our product candidates are successfully completed, we will be able to submit an NDA to the FDA or that any NDA we submit will be approved by the FDA in a timely manner, if at all. After completing clinical trials for a product candidate in humans, a drug dossier is prepared and submitted to the FDA as an NDA, and includes all pre-clinical studies and clinical trial data relevant to the safety and effectiveness of the product at the suggested dose and duration of use for the proposed indication as well as manufacturing information, in order to allow the FDA to review such drug dossier and to consider a product candidate for approval for commercialization in the United States. If we or our collaborators are unable to submit an NDA with respect to any of our current product candidates, if any NDA we or our collaborators submit is not approved by the FDA, or we or our collaborators elect not to file an NDA, or if we or our collaborators are unable to obtain any required state and local distribution licenses or similar authorizations, we will be unable to commercialize that product. The FDA can and does reject NDAs and require additional clinical trials, even when product candidates achieve favorable results in Phase 3 clinical trials. Also, we may be subject to pricing pressures from competitive products that could make it difficult or impossible for us to commercialize the product candidate successfully. If we or our collaborators fail to commercialize any of our product candidates, our business, financial condition, results of operations and prospects may be materially and adversely affected.

We or our collaboration partnerscollaborators in any potential commercial launch of our product candidates may not be successful in achieving widespread patient or physician awareness or acceptance of such product candidate. Even though we expect that our product candidatecandidates will be priced responsibly, if approved, there is no guarantee that it or any other product that we bring to the market directly or through a strategic partnercollaborator will gain market acceptance by physicians, patients, third-party payors and others in the medical community. The degree of market acceptance of any of our product candidates, if approved for commercial sale, will depend on a number of factors, including but not limited to:

Even if a product candidate we may develop in the future displays an equivalent or more favorable efficacy and safety profile in pre-clinical and clinical trials, market acceptance of the product candidate will not be fully known until after it is launched and may be negatively affected by a potential poor safety experience and the track record of other product candidates. Our efforts, or those of any strategic licensing or collaboration partner, to educate the medical community and third-party payors on the benefits of our product candidates may require significant resources, may be under-resourced compared to large well-funded pharmaceutical entities and may never be successful. If ayany product candidates we may develop in the future are approved but fail to achieve an adequate level of acceptance by physicians, patients, third-party payors and others in the medical community, we will not be able to generate sufficient revenuerevenue, either directly or through milestone and royalty payments from our collaborators, to become or remain profitable.

We face significant competition from other biotechnology and pharmaceutical companies, and our operating results will suffer if we or our collaboration partnerscollaborators fail to compete effectively.

Many of our competitors have substantially greater financial, technical and other resources, such as larger research and development staff and experienced marketing and manufacturing organizations. As a result, these companies may obtain regulatory approval more rapidly than we are able and may be more effective in selling and marketing their products. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large, established companies. Competition may increase further as a result of advances in the commercial applicability of newer technologies and greater availability of capital for investment in these industries. Our competitors may succeed in developing, acquiring or licensing, on an exclusive basis, pharmaceutical products that are easier to develop, more effective or less costly than any product candidates that we are currently developing or that we may develop. If approved, our product candidates are expected to face competition from commercially available drugs as well as drugs that are in the development pipelines of our competitors. Moreover, we also face increased competition from other companies that are using artificial intelligence, some of whom may be able to more quickly and effectively identify and develop novel product candidates compared to us and our business partners, which could impair our ability to compete effectively and have a material adverse effect on our business, results of operations or financial condition.

Unstable market and macroeconomic conditions, including elevatedtariffs andor sustainedtrade inflation,policy, may have serious adverse consequences on our business, financial condition and stock price.

As has been widely reported, we are currently operating in a period of macroeconomic uncertainty and capital markets disruption, which has been significantly impacted by domestic and global monetary and fiscal policy, trade regulations, including changes in trade policies, tariffs or other trade restrictions or the threat of such actions, geopolitical instability, including ongoing military conflicts between Russia and Ukraine and in the Middle East, rising tensions between China and Taiwan, and high interest rates. 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. WeIn continueaddition, in September 2025, the United States announced the imposition of up to monitor100% thesetariffs eventson imported branded or patented pharmaceuticals, subject to certain exceptions. There remains substantial uncertainty as to whether and when such tariffs may go into effect and whether such tariffs would apply to the potentialimportation impactof onactive ourpharmaceutical business.ingredients or bulk drug products that are intended for use in clinical trials and, more generally, about the duration of existing tariffs, tariff levels, implementation of announced tariffs, litigation challenging tariffs and whether additional tariffs or retaliatory actions may be imposed, modified or suspended. Although we do not believe that inflationthe hasmacroeconomic factors discussed above have had a material impact on our financial position or results of operations to date, our financial position or results of operations may be adversely affected in the future due to thethese macroeconomic factors discussed above,factors, and such factors may lead to increases in the cost of manufacturing our product candidates and delays in initiating trials. In addition, global credit and financial markets have experienced extreme volatility and disruptionsdisruption in the past several years and the foregoing factors have led to and may continue to cause diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, uncertainty about economic stability and increasedcontinued inflation.

If our operations are found to be in violation of any of these laws or any other governmental laws and regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, damages, fines, disgorgement, imprisonment, integrity oversight and reporting obligations, exclusion from government funded healthcare programs, such as Medicare and Medicaid, disgorgement, contractual damages, reputational harm, diminished profits and the curtailment or restructuring of our operations. If, and to the extent that, we or our collaboration partnerscollaborators are unable to comply with these regulations, our ability to earn potential royalties from sales of product candidates under our collaboration agreements would be materially and adversely impacted. If any of the physicians or other healthcare providers or entities with whom we expect to do business is found to be not in compliance with applicable laws, they may be subject to significant criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs. The imposition of any of these penalties or other commercial limitations could negatively impact our collaboration arrangements or cause our collaboration partnerscollaborators to terminate the related license and collaboration agreement, either of which would materially and adversely affect our business, financial condition and results of operations.

Our business is increasingly dependent on critical, complex and interdependent information technology systems, including internet-based systems, to support business processes as well as internal and external communications. The size and complexity of our internal computer systems and those of our CROs, contract manufacturers, collaboration partners,collaborators, and other third parties on which we rely may make them potentially vulnerable to breakdown, telecommunications and electrical failures, and malicious intrusion such as ransomware and computer viruses that may result in the impairment of key business processes. Our systems are potentially vulnerable to cybersecurity breaches, by employees or others, which may expose sensitive data to unauthorized persons. The increasing use of artificial intelligence technologies by hackers may materially increase the sophistication, frequency and impact of cybersecurity attacks against us. Such cybersecurity breaches or other cybersecurity incidents may allow hackers access to our pre-clinical compounds, strategies, discoveries, trade secrets and/or other confidential information. Additionally, sensitive data could be leaked, disclosed or revealed as a result of or in connection with our employees’, personnel’s, vendors’ or partners’ use of generative artificial intelligence technologies. Any disruption or cybersecurity incident, to the extent it was to result in the loss, destruction, unavailability, alteration or dissemination of, or damage to, our data or applications, or for it to be believed or reported that any of these occurred, could harm our reputation, compel us to comply with federal and/or state breach notification laws, subject us to mandatory corrective action, require us to verify the correctness of database contents and otherwise subject us to liability under laws and regulations that protect personal data, resulting in increased costs or loss of revenue. The risk of a cybersecurity incident or other informational technology disruption, particularly through cyber-attacks, has generally increased as the number, intensity and sophistication of attempted attacks and intrusions from around the world has increased. If we are unable to prevent such cybersecurity incidents or privacy violations or implement satisfactory remedial measures, our operations could be disrupted, and we may suffer loss of reputation, financial loss and other regulatory penalties.

As more groups become engaged in scientific research and product development in fields related to our product candidates, such as hepcidin mimetics or IL-23R, the risk of our patents, or patents that we have in-licensed, being challenged through patent interferences, derivation proceedings, oppositions, re-examinations, litigation or other means will likely increase. An adverse outcome in a patent dispute could have a material adverse effect on our business by:

An adverse outcome in a patent dispute could severely harm our collaborations or cause our collaboration partnerscollaborators to terminate their respective agreements.

Litigation or other legal proceedings relating to intellectual property claims, with or without merit, are unpredictable and generally expensive and time-consumingtime consuming and, even if resolved in our favor, are likely to divert significant resources from our core business, including distracting our technical and management personnel from their normal responsibilities. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the market price of our common stock. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their greater financial resources and more mature and developed intellectual property portfolios. Accordingly, despite our efforts, we may not be able to prevent third parties from infringing upon or misappropriating or from successfully challenging our intellectual property rights. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace.

Because we expect to rely on third parties in the development and manufacture of our product candidates, we must, at times, share trade secrets with them. We seek to protect our proprietary technology in part by entering into confidentiality agreements and, if applicable, material transfer agreements, consulting agreements or other similar agreements with our advisors, employees, third-party contractors and consultants prior to beginning research or disclosing proprietary information. These agreements typically limit the rights of the third parties to use or disclose our confidential information, including our trade secrets. Despite the contractual provisions employed when working with third parties, the need to share trade secrets and other confidential information increases the risk that such trade secrets become known by our competitors, are inadvertently incorporated into the technology of others, or are disclosed or used in violation of these agreements. Enforcing a claim that a party illegally obtained and is using our trade secrets is challenging and the outcome is unpredictable. In addition, courts outside of the United States may be less willing to protect trade secrets. Given that our proprietary position is based, in part, on our know-how and trade secrets, a competitor’s discovery of our trade secrets or other unauthorized use or disclosure would impair our competitive position and may have an adverse effect on our business and results of operations.

InPN-881. theWe fourthare quarter of 2024, we announced the selection ofdeveloping PN-881, a potential best-in-class oral peptide IL-17 antagonist, as a development candidate for the treatment of immune-mediated skin diseases. PN-881 targets three IL-17 dimers (IL-17 AA, AF and FF), whichand may offer potential treatment options for plaque psoriasis, psoriatic arthritis (“PsA”), hidradenitis suppurativa (“HS”), spondyloarthritis, plaque psoriasis and psoriatic arthritis (“PsA”). Investigational New Drug (“IND”), or foreign equivalent, enabling studies are ongoing, and we expect to initiate a PN-881 Phase 1 study in the fourth quarter of 2025.spondyloarthritis.

We have incurred cumulative net losses from inception through December 31, 20242025 of $340.5$470.7 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, productclinical development,development and pre-clinical discovery programs and pre-commercialization activities. As a result, we may incur losses in the future as we continue the development of, and seek regulatory approval for, our product candidates.programs.

There has been uncertainty and disruption in the global economy and financial markets due to a number of factors, including but not limited to geopolitical instability, inflationary pressures, high interest rates, a recessionary environment, domestic and global monetary and fiscal policy, changes in trade policies, including tariffs or other trade restrictions or the threat of such actions,actions bankingand retaliatory actions. Our business may also be impacted by changes or disruptions at the FDA and other financialgovernment institution instability and other factors.agencies. We have taken into consideration any known impacts into 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, circumstances change, and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions.

Accounting Standards Codification Topic 606, Revenue from Contracts with Customers requires us to allocate the arrangement consideration on a relative standalone selling price basis for each performance obligation after determining the transaction price of the contract and identifying the performance obligations to which that amount should be allocated. The relative standalone selling price is defined as the price at which an entity would sell a promised good or service separately to a customer. If other observable transactions in which we have sold the same performance obligation separately are not available, we estimate the standalone selling price of each performance obligation. Key assumptions to determine the standalone selling price may include forecastedforecast revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilitiesprobability of technical and regulatory success.

Whenever we determine that goods or services promised in a contract should be accounted for as a combined performance obligation over time, we determine the period over which the performance obligations will be performed and revenue will be recognized. Revenue is recognized using the proportional performance method. Costs incurred or labor hours are typically used as the measure of performance. Management’s judgment is required into determiningdetermine the level of effort required under an arrangement and the period over which we expect to complete our performance obligations. If we determine that the performance obligation is satisfied over time, any upfront payment received is initially recorded as deferred revenue on our consolidated balance sheets.

Our license and collaboration revenue is derived from payments we receive from our collaboration partners under the Takeda Collaboration Agreement and the JNJ License and Collaboration Agreement and the Takeda Collaboration Agreement. We expect our revenue to increase significantly in future periods due to the receipt of milestone payments, including payments related to NDA approvals, the potential exercise of our opt-out rights under the Takeda Collaboration Agreement, and royalties, if NDA approval is received for Icotyde in psoriasis and/or rusfertide in PV and one or both of these products are commercialized. See Note 3 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

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,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.

We expect our research and development expenses to increase in the near term as compared to prior year periods as we continue to focus our resources toward (i) progressing our rusfertide program into late stage clinical trials and preparing for regulatory filings and commercialization, and (ii) advancing our pre-clinical and drug discovery research and clinical programs, including progressing our recently nominated product development candidatecandidates PN-881PN-881, PN-477, PN-458 and PN-8047 through IND-enabling studies, or foreign equivalents. We do not intend to dedicate further internal resources to clinical development or contract manufacturing activities for our PN-943 clinical program. The process of conducting research, identifying potential product candidates, conducting pre-clinical studies 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 be able to 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.

General and administrative expenses consist of personnel costs, allocated facilities costscosts, and other expenses for outside professional services, including legal, human resources,resources and audit and accounting services, IT and pre-commercialization expenses, including selling and marketing costs.services. Personnel costs consist of salaries, benefits and stock-based compensation. Allocated expensescosts 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 to support 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 consists of interest earned on our cash, cash equivalents,equivalents and marketable securities, which is comprised of contractual interest, premium amortization and discount accretion.

Other income (expense), net consists primarily of amounts related to foreign exchange gains and losses, realized gains and losses on marketable securities, and related items.

Our business, results of operations and financial conditionscondition are subject to various risks. These risks are described elsewhere in this Quarterly Report on Form 10-Q and in our other filings with the SEC, including our Annual Report on Form 10-K for the year ended December 31, 2025. ThereExcept as disclosed below, there have been no material changes from the risk factors identified in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

This Quarterly Report contains certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements other than statements of historical fact, including statements concerning our plans, objectives, goals, strategies, future events, future revenues or performance, financing needs, expectations, plans or intentions relating to clinical development, product candidates, the regulatory approval process, products and markets, and business trends and other information referred to under the sections entitled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” are forward-looking statements. These statements are subject to substantial known and unknown risks, uncertainties and other factors that may cause our actual results, outcomes, performance or achievements, or the timing of such results, outcomes, performance or achievements, to be materially different from any results, outcomes, performances or achievements expressed or implied by the forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “anticipates,” “assumes,” “believes,” “commitments,” “could,” “estimates,” “expects,” “forecasts,” “intends,” “may,” “plans,” “potential,” “predicts,” “projects,” “should,” “targets,” “will,” “would,” “seeks” and similar expressions intended to identify forward-looking statements. Forward-looking statements reflect our current views with respect to future events, are based on assumptions, and are subject to risks, uncertainties and other important factors, including, among other things, the potential for our programs; the timing, initiation, progress and expected results of our clinical trials and research and development programs, including enrollment, data, costs and regulatory submissions and approvals; our cash runway; our ability to advance product candidates into, and successfully complete, nonclinicalnon-clinical studies and clinical trials; our eligibility for, and any expected benefits of, any U.S. Food and Drug Administration (“FDA”) programs or special designations; the potential for eventual regulatory approval and commercialization of our product candidates; the commercialization of our product candidates, if approvedapproved, which for ICOTYDE and rusfertide depends largely on the efforts of our collaboration partners; our ability and the potential to successfully manufacture and supply our product candidates for clinical trials and for commercial use, if approved; the pricing, coverage, and reimbursement of our product candidates, if approved; our potential receipt of milestone payments and royalties under our collaboration agreements; future operating results; our ability and that of our collaboration partners to generate sales, income or cash flow; our estimates regarding expenses, capital requirements, and needs for additional financing and our ability to obtain additional capital; our ability to retain the continued service of our key executives and to identify, hire, and retain additional qualified professionals; developments relating to our competitors and our industry, including competing product candidates and therapies; uncertainty and disruption in the global economy and financial markets due to a number of factors, including but not limited to geopolitical instability, such as the ongoing military conflicts between Russia and Ukraine and in the Middle East and rising tensions between China and Taiwan, elevated and sustained inflation, high oil and other commodity prices and changes in trade policies, including tariffs or other trade restrictions or the threat of such actions and retaliatory actions; the availability of credit; and other factors. Forward-looking statements involve risks, uncertainties and assumptions that are beyond our ability to control or predict, including those risks, uncertainties and assumptions discussed in Part II, Item 1A, of this Quarterly Report, Part 1. Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2025 and in our other filings with the SEC. These statements are based on information available to us as of the date of this Quarterly Report and, while we believe such information provides a reasonable basis for these statements, the information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. Given these risks, uncertainties and other important factors, you should not place undue reliance on these forward-looking statements. Also, forward-looking statements represent our estimates and assumptions only as of the date of this Quarterly Report. Except as required by law, we assume no obligation to update any forward-looking statements publicly, or to update the reasons actual results or outcomes could differ materially from those anticipated in any forward-looking statements, whether as a result of new information, future developments, changes in assumptions or otherwise. We caution investors that our business and financial performance are subject to substantial risks and uncertainties.

We are a discovery through late-stage development biopharmaceutical company with a proprietary peptide technology platform that enables de novo discovery of peptide therapeutics. Our development products and discovery programs fall into three broad therapeutic areas: (i) inflammation and immunology (“I&I”), (ii) hematology and (iii) metabolic diseases. Our aim is to develop medicines for biologically and commercially validated targets which demonstrate a strong differentiation compared to existing therapies.

Rusfertide is a first-in-class investigational injectable mimetic of the natural hormone hepcidin in development for the treatment of the rare blood disorder polycythemia vera (“PV”). We discovered rusfertide, advanced it into Phase 3 development, and in early 2024 entered into a co-developmentlicense and co-commercializationcollaboration arrangementagreement with Takeda Pharmaceuticals, Inc. (“Takeda”) under a license and collaboration agreement entered into in January 2024.2024 (the “Takeda Collaboration Agreement”). We remained primarily responsible for clinical development activities through rusfertide’s New Drug Application (“NDA”) filing for the treatment of erythrocytosis in patients with PV, which we and Takeda submitted in December 2025.2025, and Takeda is responsible for further development and commercialization. In March 2026, the FDA accepted the NDA and granted Priority Review status for rusfertide. Rusfertide has also previously received Orphan Drug status, Fast Track designation and, in August 2025, Breakthrough Therapy designation (“BTD”). BTD is a process designed to expedite the development and review of drugs that are intended to treat a serious condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapies. BTD also provides eligibility for priority NDA review, and Orphan Drug status qualifies sponsors for various incentives, including the potential for extended market exclusivity. The NDA for rusfertide is currently under priority review by the FDA, with a Prescription Drug User Fee Act target action date in the third quarter ofAugust 2026. Takeda has disclosed that it expects to launch rusfertide in the second half of 2026, subject to regulatory approval.

PN-881. We are developing PN-881, a potential best-in-class oral peptide IL-17 antagonist, for the treatment of immune-mediated skin diseases. PN-881 targets three IL-17 dimers (IL-17 AA, AF and FF), and may offer potential treatment options for plaque psoriasis, psoriatic arthritis (“PsA”),arthritis, hidradenitis suppurativa (“HS”),suppurativa, and spondyloarthritis.

In October 2025, the first human subject was dosed in our Phase 1 trial of PN-881 (ClinicalTrials.gov identifier NCT07153146) evaluating its safety, tolerability, pharmacokinetics and pharmacodynamics in healthy adults. ResultsWe ofbelieve thedata PN-881from our Phase 1 study aresupports our decision to advance PN-881 into a comprehensive Phase 2b psoriasis program, with initiation expected to inform the design and dosing in aearly subsequentfirst dose-rangingquarter psoriasis trial. We expect to complete the Phase 1 study by mid-2026 and initiate a Phase 2 trial by the end of 2026.2027.

PN-477. In June 2025, we nominated PN-477, a potential best-in-class novel triple GLP-1, GIP and GCG receptor agonist peptide with oral (“PN-477o”) and subcutaneous (“PN-477sc”) routes of administration, as a development candidate for the treatment of obesity. We designed PN-477 to offer an optimal combination of total body weight loss, improved gastrointestinal tolerability and fat to lean mass ratio, with the dosing convenience of a once-daily oral agent and the added optionality of a once-weekly subcutaneous administration. IND-enablingA studiesPhase of1 PN-477clinical arestudy underwayfor PN-477sc has been initiated, and the initiation of a Phase 1 clinicalstudy studies in PN-477sc andfor PN-477o areis anticipated in mid-2026 and the first quarterhalf of 2027, respectively.2027.

PN-458. In December 2025, we nominated development candidate PN-458, a potential best-in-class novel dual GLP-1 and GIP receptor agonist peptide, as a development candidate for the treatment of obesity, with optionality for both an oral (“PN-458o”) and subcutaneous (“PN-458sc”) formulation.obesity. IND-enabling studies are ongoing, with the initiation of a Phase 1 study for PN-458othe andPN-458 PN-458scoral areformulation ongoing.anticipated in the second half of 2027.

PN-8047. In December 2025, we nominated development candidate PN-8047, an orally administered small molecule hepcidin functional mimetic, which we believe may be complementary to the injectable rusfertide for offering the best treatment options for PV. IND-enabling studies for PN-8047 are ongoing.ongoing, with the initiation of a Phase 1 study anticipated in the first quarter of 2027.

We ended the firstsecond quarter of 2026 with cash, cash equivalents and marketable securities of approximately $620.3$849.5 million, as compared to cash, cash equivalents and marketable securities of approximately $646.0 million as of December 31, 2025. For the remainder of 2026 and beyond, we are eligible to receive significant milestone, royalty and other payments from our collaborations with JNJ and Takeda, as described below. The receipt of future royalties and commercial milestones is contingent upon the relevant products receiving FDA approval and achieving a successful commercial launch.

License and Collaboration Agreements

In March 2026, we earned a $50.0 million milestone payment upon FDA approval of ICOTYDE for the treatment of moderate-to-severe plaque psoriasis in adults and pediatric patients 12 years of age or older who weigh at least 40 kg and are candidates for systemic therapy or phototherapy. As of MarchJune 31,30, 2026, we have earned a total of $387.5 million in non-refundable upfront and milestone payments from JNJ under the agreement. We are eligible to receive up to $580.0 million in future development and sales milestone payments, including the following potential milestones:

We will also receive upward tieringtiered royalties on net worldwide ICOTYDE product sales at percentages ranging from 6% to 10%. Our weighted-average royalty rate on the first $4.0 billion in annual net sales is 7.25%, and the rate on net sales over $4.0 billion is 10%. SeeThe Noteultimate 3magnitude toof our royalty stream, along with the condensedachievement consolidatedof financialdevelopment statementsand includedcommercial elsewheremilestones, will depend upon ICOTYDE’s commercial launch success and market trajectory, which depends on the efforts of our collaboration partner, as well as the successful clinical development, regulatory approval, and commercialization of ICOTYDE in this Quarterly Report forthe additional information.indications currently being studied.

In January 2024, we entered into a worldwide license and collaboration agreement for rusfertide with Takeda (the “Takeda Collaboration Agreement”) related to rusfertide (and specified second-generation injectable hepcidin mimetic compounds developed and commercialized under the agreement that are not currently in development). In December 2025, we and Takeda submitted an NDA to the FDA for rusfertide in PV, which is currently under priority review. We were primarily responsible for the clinical development of rusfertide through NDA filing and remain primarily responsible for the conduct of ongoing rusfertide long-term extension studies. Under the terms of the agreement, we received an upfront payment of $300.0 million in April 2024 and a $25.0 million milestone payment in September 2025 upon completion of the Phase 3 VERIFY clinical trial (NCT05210790) report.

Effective April 28, 2026, we exercised our right to opt-out of the U.S. profit and loss sharing arrangement (50% to us and 50% to Takeda) under the Takeda Collaboration Agreement. The opt-out election triggered a $200.0 million payment to us, withwhich we received in the second quarter of 2026, and we also became eligible to receive an additional $200.0 million opt-out fee and a separate $75.0 million milestonemilestone, both of which are due upon FDA approval of rusfertide. Following the opt-out, Takeda has an exclusive worldwide license to develop and commercialize rusfertide, and we are eligible to receive tiered royalties ranging from 14% to 29% on annual worldwide net sales, with an approximate weighted-average royalty rate of 21% at $1.5 billion in annual net sales and a rate of 29% for incremental annual net sales over $1.5 billion. In addition, under the agreement, we are eligible to receive up to an aggregate of $975.0$775.0 million in development, regulatory and sales milestones, including the $25.0 million milestone payment already received in September 2025.milestones. Upcoming potential development milestones and potential sales milestones under the agreement include the following:

We have incurred cumulative net losses from inception through MarchJune 31,30, 2026 of $466.9$304.0 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, clinical development and pre-clinical discovery programs.

Critical Accounting PolicesPolicies and Estimates

There have been no material changes to our critical accounting policies during the three and six months ended MarchJune 31,30, 2026, as compared to those disclosed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Estimates” in our Annual Report for the year ended December 31, 2025 filed with the SEC on February 25, 2026.

Our license and collaboration revenue is derived from payments we receive from our collaboration partners under the JNJ License and Collaboration Agreement and the Takeda Collaboration Agreement. We expect our revenue to increase significantly in future periods due to the receipt of milestone payments, including payments related to NDA approvals and the exercise of our opt-out right under the Takeda Collaboration Agreement,Agreement and royalties for sales of ICOTYDE for moderate-to-severe plaque psoriasis, and in other indications if approved. We also expect to receive royalties for rusfertide in PV if NDA approval is received and the product is successfully commercialized. See Note 3 to the condensed consolidated financial statements included elsewhere in this Quarterly Report for additional information.

We expect our research and development expenses to increase in the near term as compared to the prior year period as we continue to focus our resources toward advancing our pre-clinical and drug discovery research and clinical programs, including progressing our product development candidates PN-881, PN-477, PN-458 and PN-8047 through IND-enabling studies, or foreign equivalents. The process of conducting research, identifying potential product candidates, conducting pre-clinical studies 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 current or future 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 be able to generate revenue from the commercialization and sale of any of our current or future product candidates. Our research and development programs are subject to change from time to time as we evaluate our priorities and available resources.

Other (Expense) Income, Net

Other (expense) income, net consists primarily of amounts related to foreign exchange gains and losses, realized gains and losses on sale of marketable securities and related items.

Comparison of the Three Months Ended MarchJune 31,30, 2026 and 2025

Our revenue is derived from licensing and collaboration agreements and is highly variable and dependent upon factors such as the timing of when regulatory and sales milestones are achieved, if at all, commercial launch efforts by our collaboration partners, and the accounting for any upfront payments associated with any existing or new agreements.

As described above, we opted out of the U.S. profit and loss sharing arrangement right under the Takeda Collaboration Agreement in April 2026 and are eligible to receive upboth toan $400.0additional $200.0 million inopt-out payments,payment along withand an enhanced milestone payment of $75.0 million upon the FDA’sFDA approval of rusfertide.rusfertide, which is expected in August 2026. In addition, we expect to receive significant royalties in 2026 from the launch of ICOTYDE and may receive royalties and sales milestones from rusfertide, pending potential FDA approval and commercial launch.

Research and development expenses increased $10.8$5.0 million, or 30%,14%, from $35.9$37.0 million for the three months ended MarchJune 31,30, 2025 to $46.7$42.1 million for the three months ended MarchJune 31,30, 2026. The increase was primarily due to an increase of $8.9$8.6 million in costs related to our Phase 1 study for development candidate PN-881 initiated in the third quarter of 2025 and aan $6.0$8.4 million increase in pre-clinical and drug discovery research program expense, partially offset by a decrease of $4.0$12.0 million in rusfertide expenses primarily related to the completion of our Phase 3 VERIFY trial during the first quarter of 2025.

We had 100108 and 97100 full-time equivalent research and development head countheadcount as of MarchJune 31,30, 2026 and 2025, respectively. Research and development personnel-related expenses for the three months ended MarchJune 31,30, 2026 increased by $1.0$1.9 million as compared to the three months ended MarchJune 31,30, 2025, primarily driven by increases in wageswages, benefits and benefits.stock-based compensation.

We expect research and development expenses to increase significantly asin the second half of 2026 compared to priorthe periodsfirst half of 2026. The increase is expected to be driven primarily by the advancement of PN-881 into a comprehensive Phase 2b psoriasis program, planned investments in clinical manufacturing and related activities, including at-risk expenditures to ensure readiness for other programs as wethey continueadvance to investclinical development (PN-477sc, PN-458, PN-8047), additional pre-clinical discovery programs, and increases in new discovery programsheadcount and ourstock-based disclosedcompensation pre-clinical programs and advance multiple clinical candidates into development.expense. The timing and magnitude of these expenses will vary depending on the progress orof our programs, including the initiation and pace of clinical trials and related development activities.

General and administrative expenses increased $1.5$2.1 million, or 13%,20%, from $11.7$10.6 million for the three months ended MarchJune 31,30, 2025 to $13.3$12.6 million for the three months ended MarchJune 31,30, 2026. The increase was primarily due to a $1.8 millionan increase in personnel-related expenses, primarilyexpenses driven by increases in wages andwages, benefits and stock-based compensation, partially offset by a $0.3 million decrease in professional services and other expenses.compensation.

We had 3133 and 2730 full-time equivalent general and administrative head countheadcount as of MarchJune 31,30, 2026 and 2025, respectively.

Interest income decreased by $1.7$1.0 million, or 22%,13%, from $7.6$7.4 million for the three months ended MarchJune 31,30, 2025 to $5.9 for$6.4 million for the three months ended MarchJune 31,30, 2026 primarily due to alower decrease in invested balancesyields and lower effectiveaverage yields.investment balance as compared to the prior period.

Income Tax BenefitExpense

Income tax benefitexpense was $1.5$2.3 million and zero$0.2 million for the three months ended MarchJune 31,30, 2026 and 2025, respectively. IncomeThe increase in income tax benefitexpense for the three months ended MarchJune 31,30, 2026 includedwas primarily due to pretax income recorded as compared to a discretepretax creditloss for stock-basedthe compensationprior expenseyear specificperiod. toThe effective tax rate was 1.4% and 0% for the currentthree quarter.months ended June 30, 2026 and 2025, respectively.

We had $620.3$849.5 million and $646.0 million in cash, cash equivalents and marketable securities as of MarchJune 31,30, 2026 and December 31, 2025, respectively. Historically, we have funded our operations primarily from receipt of payments under collaboration agreements, as discussed in “Collaboration Agreements” above, and net proceeds from the sale of shares of our common stock.