NASDAQ: PHAT

In May 2021, the FDA granted qualified infectious disease product, or QIDP, designation to VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK, resulting in an extension of the five-year new chemical entity, or NCE, exclusivity by an additional five years. In December 2024, we submitted a citizen petition requesting that the FDA update the Orange Book listing for VOQUEZNA to reflect the same ten-year period of NCE exclusivity applicable to VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK. In June 2025, the FDA granted the petition and updated the Orange Book listing for VOQUEZNA to reflect the ten-year period of NCE exclusivity for vonoprazan. As a result, all three VOQUEZNA products now have NCE exclusivity extending through May 3, 2032.

In the fourth quarter of 2025, we initiated a Phase 2 clinical trial evaluating vonoprazan in the treatment of adults with eosinophilic esophagitis, or EoE. While our current focus is on continued U.S. commercialization of VOQUEZNA products for GERD and H. pylori, we are also evaluating other potential life-cycle management opportunities for vonoprazan. We may also explore the potential for vonoprazan in Europe and Canada, as well as opportunities to in-license or acquire additional clinical or commercial-stage product candidates for GI diseases.

Our Products and Commercialization

All of our revenue is derived from the sale of three products in the United States: VOQUEZNA (vonoprazan) tablets which are approved for the healing and maintenance of healing of all grades of Erosive GERD and relief of heartburn associated with Erosive GERD in adults, and for the relief of heartburn associated with Non-Erosive GERD in adults, as well as, in combination with amoxicillin with or without clarithromycin, for the treatment of H. pylori infection, and VOQUEZNA DUAL PAK, comprised of vonoprazan co-packaged with amoxicillin, and VOQUEZNA TRIPLE PAK, comprised of vonoprazan co-packaged with amoxicillin and clarithromycin, which are both approved for the treatment of H. pylori infection. We began U.S. commercialization of VOQUEZNA for the treatment of Erosive GERD and H. pylori infection, and of VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK for the treatment of H. pylori infection, in the fourth quarter of 2023. In July 2024, the FDA also approved VOQUEZNA for the relief of heartburn associated with Non-Erosive GERD.

The sections below describe the diseases our approved products target, the clinical data supporting their use, and our commercialization efforts.

4

Our Strategy

Our strategy is focused on building a sustainable, commercial-stage GI company centered on the commercialization of VOQUEZNA and, in the future, the disciplined expansion of our product portfolio.

Our key strategic priorities include:

•
Maximizing the U.S. commercial opportunity for VOQUEZNA in its approved indications in the treatment of GERD through a targeted sales force initially focused on gastroenterologists and other high-prescribing healthcare providers, and in the future, potentially expanding marketing and sales efforts to target more broadly those primary care physicians who treat GERD;

•
Selectively pursuing life-cycle management opportunities for vonoprazan, including potential additional indications and formulations;

•
Exploring the potential for vonoprazan in Europe, Canada, U.S. over-the counter, or OTC, use, and other potential market expansions, including evaluating the feasibility and practicality of potential collaboration or licensing arrangements;

•
Maintaining a disciplined and selective approach to business development, including evaluating opportunities to in-license or acquire additional clinical- or commercial-stage product candidates for GI diseases; and

•
Operating with financial discipline, prioritizing efficient capital allocation and effective management of manufacturing and supply arrangements.

We continually assess our strategic priorities in light of evolving market conditions, regulatory developments, clinical feasibility, commercial potential, competitive dynamics and our available resources. Our ability to execute on this strategy is subject to significant risks and uncertainties, including those described elsewhere in this Annual Report on Form 10-K.

Disease Background

Gastroesophageal Reflux Disease (GERD)

Gastroesophageal reflux disease, or GERD, is a chronic digestive disorder characterized by the reflux of gastric contents into the esophagus, which can result in symptoms such as heartburn, regurgitation and chest discomfort, as well as potential esophageal injury. GERD is one of the most common GI conditions in the U.S, affecting an estimated 65 million adults in the U.S. Exposure of the esophagus to gastric acid is a primary contributor to GERD symptoms and, in patients with erosive disease, damage to the esophageal lining. Accordingly, pharmacologic therapies designed to suppress gastric acid secretion are a cornerstone of treatment for both Erosive and Non-Erosive GERD and are commonly used for long-term symptom management.

GERD is generally classified into two categories: Erosive GERD, also referred to as erosive esophagitis, and Non-Erosive GERD. Erosive GERD is characterized by visible injury to the esophageal lining and is believed to affect an estimated 20 million adults in the U.S. If left untreated, Erosive GERD may progress to complications such as peptic stricture, Barrett’s esophagus or, in some cases, esophageal cancer. Non-Erosive GERD, which is believed to affect an estimated 45 million adults in the U.S, is characterized by persistent symptoms and abnormal gastric acid exposure in the absence of visible esophageal injury. Non-Erosive GERD represents the largest segment of diagnosed GERD patients and accounts for a substantial proportion of individuals seeking medical treatment for chronic heartburn.

GERD is typically a chronic condition. Patients with GERD often initially manage symptoms with over-the-counter antacids or acid-reducing agents for intermittent or mild symptoms. Patients with more frequent, persistent or severe symptoms, or with evidence of esophageal injury, are typically treated with prescription acid-suppressive therapies to try to manage symptoms and reduce the risk of disease progression. We estimate that approximately 22 million adults are prescribed treatments for GERD in the U.S. each year, of which 7 million are treated for Erosive GERD and 15 million are treated for Non-Erosive GERD. Proton pump inhibitors, or PPIs, have historically been the standard of care for GERD among prescribed treatments and are widely prescribed for both erosive and non-erosive disease. We estimate there are approximately 110 million PPI prescriptions written and filled annually across all indications. The PPI class includes drugs such as Prilosec (omeprazole), Nexium (esomeprazole), and Prevacid (lansoprazole). Prior to the introduction of generic and OTC alternatives, annual PPI class sales reached approximately $12.5 billion in the United States, with peak sales for individual brands of approximately $3.7 billion for Prilosec, $3.5 billion for Nexium, and $3.4

5

billion for Prevacid. PPIs reduce gastric acid secretion by irreversibly inhibiting active proton pumps in gastric parietal cells and are typically dosed prior to meals, as their activity depends on acid-mediated activation and the presence of meal-stimulated proton pumps. An estimated 40% of patients with GERD experience inadequate symptom relief from PPI therapy, including persistent symptoms, delayed symptom relief or incomplete healing. In addition, variability in patient response and strict dosing requirements may limit the effectiveness of PPIs for certain patients. Patients with GERD who continue to experience heartburn symptoms are often referred to gastroenterologists for evaluation and then return to their primary care physicians for ongoing management.

We believe GERD represents an attractive commercial opportunity due to its high prevalence, chronic nature and the ongoing need for effective treatment options for patients with suboptimal outcomes on existing PPI therapies.

H Pylori

H. pylori is a bacterial infection of the stomach that is a leading cause of peptic ulcer disease and is associated with an increased risk of gastric cancer. Infection is typically acquired in childhood and can persist for decades if left untreated. Many infected individuals are asymptomatic; however, chronic infection can result in clinically significant gastrointestinal disease. The primary goal of treatment for H. pylori infection is eradication of the bacterium. Eradication typically requires combination therapy consisting of acid suppression and multiple antibiotics administered over a defined treatment course. Acid suppression plays an important role in the treatment of H. pylori by enhancing antibiotic stability and activity within the gastric environment. PPIs, in combination with antibiotics, have historically been the standard of care for the treatment of H. pylori infection.

Treatment of H. pylori infection can be complicated by a number of factors, including increasing rates of antibiotic resistance, regimen complexity, and challenges with patient adherence. As a result, eradication rates can vary, and some patients may require retreatment. These factors contribute to the continued need for effective and well-tolerated treatment regimens for H. pylori infection.

Clinical Overview of Vonoprazan

Mechanism of Action

Vonoprazan is an oral, small-molecule PCAB that suppresses gastric acid secretion by inhibiting the gastric H+/K+ -ATPase enzyme system at the secretory surface of the gastric parietal cell. This enzyme, commonly referred to as the gastric proton pump, is responsible for the final step of stomach acid production. By blocking the final step of acid production in a potassium-competitive manner, vonoprazan suppresses both basal and stimulated gastric acid secretion.

Unlike PPIs, which require activation in an acidic environment, vonoprazan does not require acid-mediated activation. Vonoprazan binds to the proton pump in a noncovalent and reversible manner and may selectively concentrate in parietal cells in both resting and stimulated states. In practical terms, vonoprazan blocks the final step of stomach acid production directly, which allows it to reduce acid secretion without requiring activation in an acidic environment. In a pharmacokinetic/ pharmacodynamic study conducted in healthy volunteers, vonoprazan demonstrated rapid onset (increased PH in two-three hours), potent suppression (Day 1 mean pH of 4.6), and durable 24-hour acid control of gastric acid secretion compared to a PPI, as measured by intragastric pH.

Clinical Data Supporting VOQUEZNA for GERD

Erosive GERD. FDA approval of VOQUEZNA for the healing and maintenance of healing of all grades of erosive esophagitis and for the relief of heartburn associated with Erosive GERD was based on results from PHALCON-EE, a randomized, controlled Phase 3 clinical trial conducted in the United States and Europe. PHALCON-EE evaluated vonoprazan compared to lansoprazole for both the healing and maintenance of healing of erosive esophagitis in adult patients with Erosive GERD. In PHALCON-EE, vonoprazan met the primary healing endpoint of the trial by demonstrating non-inferiority to lansoprazole in the number of patients who showed complete healing of erosive esophagitis after eight weeks of treatment. In addition, in a pre-specified secondary endpoint, vonoprazan demonstrated superior healing rates after two weeks of treatment in patients with moderate-to-severe Erosive GERD compared to lansoprazole, based on a pre-specified secondary analysis. Following the healing phase, healed patients entered a maintenance phase in which vonoprazan 10 mg and 20 mg were compared to lansoprazole in the maintenance of healing. In the maintenance phase of the trial, both doses of vonoprazan (10 mg and 20 mg) met the primary endpoint of non-inferiority compared to lansoprazole in the number of all patients who maintained healing of Erosive GERD through week 24. Further, both vonoprazan doses also met a pre-specified secondary endpoint demonstrating superiority of maintenance of healing versus lansoprazole. Both vonoprazan doses also met the pre-specified secondary endpoint of demonstrating superiority of the percentage of patients with

6

moderate-to-severe disease who maintained healing of Erosive GERD through week 24. In PHALCON-EE, vonoprazan 20 mg met the secondary endpoint of showing non-inferiority to lansoprazole 30 mg in the mean percentage of 24-hour heartburn free days over the healing period, and both vonoprazan doses met the secondary endpoint of showing non-inferiority to lansoprazole 15 mg in the mean percentage of 24-hour heartburn free days over the maintenance period. Finally, vonoprazan 20 mg was also compared to lansoprazole 30 mg in a superiority test for onset of sustained resolution of heartburn by day three of the healing phase but did not achieve statistical significance. Based on the totality of clinical data, in November 2023, the FDA approved VOQUEZNA for healing and maintenance of healing of erosive esophagitis and for the relief of heartburn associated with Erosive GERD in adults.

Non-Erosive GERD. FDA approval of VOQUEZNA 10 mg tablets for the relief of heartburn associated with Non-Erosive GERD was based on results from PHALCON-NERD-301, a randomized, double-blind, placebo-controlled Phase 3 clinical trial conducted in adult patients with symptomatic GERD without visible esophageal erosions on endoscopy. The trial enrolled adult patients who experienced frequent heartburn symptoms and evaluated the efficacy of vonoprazan compared to placebo over the treatment period. In the study, both doses of vonoprazan (10 mg and 20 mg) met the primary endpoint evaluating the mean percentage of 24-hour heartburn-free days through week four by demonstrating statistical significance versus placebo. The primary endpoint assessed relief of heartburn symptoms using patient-reported outcome measures. Secondary endpoints evaluated additional measures of symptom control and consistency of response over time. Patients who completed the double-blind treatment period were eligible to enter an extension period, during which continued treatment with vonoprazan was evaluated to assess the durability of symptom relief and longer-term safety. Based on the totality of clinical data, in July 2024 the FDA approved VOQUEZNA 10 mg tablets for the relief of heartburn associated with non-Erosive GERD in adults. Non-Erosive GERD represents the largest segment of patients with diagnosed GERD and includes individuals who experience persistent symptoms in the absence of visible esophageal injury. The approval of VOQUEZNA for the relief of heartburn in Non-Erosive GERD expanded the approved indications for VOQUEZNA to address a broader population of patients with chronic GERD-related symptoms.

Clinical Data Supporting VOQUEZNA products for Helicobacter pylori Infection

FDA approval of VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK for the treatment of H. pylori infection in adults was based on results from PHALCON-HP, our Phase 3 clinical trial in the United States and Europe studying two vonoprazan-based treatment regimens for the eradication of H. pylori infection. PHALCON-HP evaluated vonoprazan triple therapy and vonoprazan dual therapy compared to lansoprazole in combination with amoxicillin and clarithromycin, or lansoprazole triple therapy. The objective of the PHALCON-HP trial was to compare eradication rates in all treated subjects as well as in two pre-identified subgroups of patients: those patients with clarithromycin resistant strains of H. pylori, and those patients who did not have clarithromycin or amoxicillin resistant strains of H. pylori. For regulatory purposes, the primary endpoint of this study was a non-inferiority comparison in the non-resistant subgroup for each of vonoprazan triple therapy and vonoprazan dual therapy compared to lansoprazole triple therapy. In PHALCON-HP, both vonoprazan-based regimens successfully met their primary endpoints. Vonoprazan triple therapy and vonoprazan dual therapy also met all secondary endpoints in the study, demonstrating superior eradication rates versus lansoprazole triple therapy in all patients and in the subgroup of patients with clarithromycin resistant strains of H. pylori. Based on the totality of clinical data, in May 2022, the FDA approved VOQUEZNA DUAL PAK, which combines vonoprazan with amoxicillin, and VOQUEZNA TRIPLE PAK, which combines vonoprazan with amoxicillin and clarithromycin, for the treatment of H. pylori infection in adults. The co-packaged formulations are designed to simplify prescribing and administration of combination therapy.

Safety Experience

The most common side effects of VOQUEZNA for treatment of Non-Erosive Esophagitis or relief of heartburn related to gastroesophageal reflux disease include: stomach inflammation, diarrhea, stomach bloating, stomach pain, nausea, indigestion, constipation, high blood pressure, and urinary tract infection. The most common side effects associated with VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK include: diarrhea, temporary changes in sense of taste, vaginal yeast infection, stomach pain, headache, high blood pressure and cold-like symptoms. Across our clinical development programs, vonoprazan was generally well tolerated. In the PHALCON-EE Phase 3 trial in Erosive GERD, the most commonly reported adverse events were gastrointestinal in nature and occurred at generally similar frequencies across vonoprazan and lansoprazole treatment groups. Rates of discontinuation due to adverse events were low during both the healing and maintenance phases. The frequency of serious adverse events was similar between treatment groups during the healing phase and remained low during the maintenance phase. The PHALCON-EE trial was conducted during the COVID-19 global pandemic. Coronavirus infection was reported in a subset of patients across treatment groups, including during the maintenance phase. Two deaths due to coronavirus infection occurred in patients treated with vonoprazan 20 mg during the PHALCON-EE study; none of the coronavirus infection events were considered related to study drug by the investigators. In Phase 3 clinical trials evaluating vonoprazan for Non-Erosive GERD, including placebo-controlled and extension phases, vonoprazan was generally well tolerated, with overall adverse event rates comparable to placebo during the double-blind

7

treatment periods. Adverse events observed during extension periods were consistent with those reported in prior vonoprazan studies. Serious adverse events were infrequent across studies, and the overall safety experience was consistent with the established clinical profile of vonoprazan. In the PHALCON-HP Phase 3 trial evaluating vonoprazan-based dual and triple therapy regimens for H. pylori infection, the overall incidence and types of adverse events observed with vonoprazan-based regimens were generally comparable to those observed with lansoprazole-based triple therapy. Discontinuation rates due to adverse events in the study were low across treatment arms.

Exclusivity

In May 2021, the FDA granted QIDP designation to VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK, resulting in an extension of the five-year NCE exclusivity by an additional five years. In December 2024, we submitted a citizen petition requesting that the FDA update the Orange Book listing for VOQUEZNA to reflect the same ten-year period of NCE exclusivity applicable to VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK. In June 2025, the FDA granted the petition and updated the Orange Book listing for VOQUEZNA to reflect the ten-year period of NCE exclusivity for vonaprazan. As a result, all three VOQUEZNA products now have NCE exclusivity extending through May 3, 2032.

Sales and Marketing

During the year ended December 31, 2025, we generated increased revenues from sales of our VOQUEZNA products compared to the prior year, reflecting continued execution of our U.S. commercial strategy following launch. The majority of our 2025 revenue was derived from sales of VOQUEZNA. During this period, we also experienced growth in prescription volume and prescriber adoption, with most prescriptions written for GERD indications. As of February 13, 2026, over 1.1 million prescriptions for VOQUEZNA tablets, VOQUEZNA DUAL PAK, and VOQUEZNA TRIPLE PAK have been filled since launch. We continue to have broad commercial payer coverage for VOQUEZNA, with access for over 120 million covered lives, representing over 80% of U.S. commercial lives. Our commercial efforts are supported by a targeted sales force and continued focus on prescriber engagement and payer access.

U.S. Commercial Organization and Sales Strategy

We have established marketing, sales, and distribution capabilities to support the commercialization of our approved products in the United States. We are independently commercializing VOQUEZNA tablets, VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK, through a targeted national sales force primarily focused on gastroenterologists and other high-prescribing healthcare providers, including select primary care physicians. We currently employ a sales force that we expect, at full strength, to consist of approximately 300 sales representatives, although the size of our sales force may vary from time. We also work with third-party pharmacy support service providers to facilitate patient access to our VOQUEZNA products. Through these arrangements, eligible patients may access programs that help identify lower out-of-pocket costs, support prior authorization submissions, and offer home delivery from licensed pharmacies. Our commercial and development activities are supported by an experienced management team with expertise in gastroenterology, product commercialization, and pharmaceutical operations.

Our commercial strategy is focused on driving awareness and adoption among healthcare providers who routinely treat patients with GERD and H. pylori infection. We prioritize engagement with high-volume prescribers of acid-suppressive therapies and focus our promotional efforts on communicating the clinical profile and approved indications of our products.

Market Access and Distribution

We actively engage with payers to maintain and expand formulary access for VOQUEZNA products. As of December 31, 2025, we had achieved broad commercial coverage for VOQUEZNA across national and regional health plans. Utilization management for access to VOQUEZNA in the treatment of GERD typically requires a generic PPI step edit via a prior authorization. We continue to evaluate opportunities to improve patient access through formulary positioning and patient support programs.

In the United States, we sell our products primarily to pharmaceutical wholesale distributors and select pharmacies, which in turn distribute our products to their customers. These may include retail pharmacies, institutions, clinics and patients. This distribution model allows us to efficiently reach healthcare providers and patients nationwide. We also work with third-party pharmacy support service providers to facilitate patient access to our VOQUEZNA products. Through these arrangements, eligible patients may access programs that help identify lower out-of-pocket costs, support prior authorization submissions, and offer home

8

delivery from licensed pharmacies. These relationships are intended to improve patient access and adherence to therapy for prescribers and patients.

Marketing and Promotional Activities

Our marketing strategy includes a combination of healthcare provider–focused and patient-facing initiatives. We utilize a range of promotional channels, including in-person sales interactions, digital engagement, and educational programs directed at healthcare providers.

We also engage in select direct-to-consumer marketing activities, including digital and streaming media platforms and other consumer-facing channels, designed to increase disease awareness and encourage appropriate patient-provider discussions.

Geographic Scope

We currently commercialize our products exclusively in the United States and do not have approved products marketed outside the United States. We continue to evaluate opportunities for vonoprazan in Europe and Canada.

Additional Vonoprazan Development Opportunities

Eosinophilic Esophagitis (EoE)

While our current focus is on the continued U.S. commercialization of VOQUEZNA products for GERD and H. pylori infection, we are also pursuing or evaluating potential lifecycle expansion opportunities for vonoprazan. In the fourth quarter of 2025, we initiated a Phase 2 clinical trial evaluating vonoprazan in the treatment of adults with EoE. The PHALCON-EOE-201 study is a randomized, double-blind, placebo-controlled Phase 2 trial in adults with EoE, designed to evaluate the efficacy and safety of vonoprazan 20 mg once daily. Approximately 80 subjects will be randomized 1:1 to vonoprazan or placebo for a 12-week treatment period, with the primary endpoint assessed at Week 12 and followed by a safety follow-up and an optional open-label extension. We anticipate topline data from this trial in 2027. EoE is an autoimmune disease with significant unmet need and can result in trouble swallowing, chest pain, vomiting and impaction of food in the esophagus, a medical emergency. There are only two FDA-approved treatments for EoE. Although not approved for this indication, PPIs are often prescribed as a first-line therapy for the treatment of EoE. In an investigator-sponsored clinical trial in Japan, vonoprazan demonstrated similar efficacy results when compared to PPIs in the treatment of patients with EoE. Given the data from this trial and the limited choices of therapies for EoE, we believe EoE is an important indication for clinical evaluation.

Other Potential Opportunities

We may explore potential research opportunities for vonoprazan in other indications or specific patient populations related to acid secretion such as Barrett’s esophagus where PPIs are the current standard of care as well as other potential formulations and packaging of vonoprazan such as an orally disintegrating tablet, or ODT, formulation. We believe that vonoprazan has a profile that would support its development in the future as an OTC product, including the potential for as-needed symptom relief and a well-tolerated safety profile. We plan to explore the economics and potential development pathway for an OTC product in this market to determine possible future strategies. We also continue to evaluate opportunities to in-license or acquire additional clinical- or commercial-stage product candidates for gastrointestinal diseases.

Competition

The biopharmaceutical industry is characterized by rapidly advancing technologies, intense competition and strong emphasis on proprietary products. We face potential competition from many sources, including major pharmaceutical, specialty pharmaceutical and biotechnology companies, academic institutions and government agencies and public and private research institutions. In the United States, VOQUEZNA, VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK all compete, and if approved in Europe and/or Canada will compete, with existing therapies and new therapies that may become available in the future.

Some of our competitors, either alone or with their strategic partners, have substantially greater financial, technical and human resources and significantly greater experience in the discovery and development of product candidates, obtaining FDA and other regulatory approvals of treatments and commercializing those treatments. These same competitors may invent technologies or products that compete with vonoprazan. Mergers and acquisitions in the biotechnology and pharmaceutical industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in

9

recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and subject recruitment for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Outside the United States, our competitors may obtain regulatory approval for, or initiate commercial launch of, their products more rapidly than we may obtain approval for or launch products containing vonoprazan, if we seek approval in those territories, which could result in our competitors establishing a strong market position before we are able to enter the market. In addition, VOQUEZNA, VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK, are priced at a premium over competitive generic products in the U.S., and our ability to compete may be affected in many cases by insurers or other third-party payers seeking to encourage the use of generic products.

For the treatment of Erosive GERD and Non-Erosive GERD, VOQUEZNA primarily competes with generic PPIs marketed by multiple pharmaceutical companies in both the prescription and OTC markets. Generic PPIs are widely available, inexpensive and well established in clinical practice. In addition, we are aware of other PPIs in development in the United States and in our licensed territories outside the United States that, if successfully developed and approved, may compete with vonoprazan.

We are also aware of several PCABs in development in the United States and in our licensed territories outside the United States, that, if approved or introduced, may compete with vonoprazan. For example, Sebela Pharmaceuticals, Inc. has publicly announced the submission of an NDA in the United States seeking approval of tegoprazan for the treatment of Erosive GERD and Non-Erosive GERD based on Phase 3 clinical trials. Outside the United States, tegoprazan is marketed in several countries, including South Korea, where it was originally developed. Daewoong Pharmaceutical Co., Ltd also markets a PCAB, fexuprazan, in certain countries outside the United States, and has indicated that it is seeking a partner to advance development of the compound in the United States. In addition, in 2025, Cinclus Pharma Holding AB initiated a Phase 3 clinical trial in Europe of another PCAB, linaprazan glurate, in patients with severe Erosive GERD and has publicly indicated its intention to initiate a second Phase 3 clinical trial in the United States to support a potential future NDA submission. Additional PCABs have been approved or are in development outside the United States and could compete with vonoprazan if introduced in our licensed territories.

For the treatment of H. pylori infection, VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK compete primarily with generic PPI-based triple and quadruple therapies, as well as with branded therapies such as Talicia, a co-formulated capsule containing omeprazole, amoxicillin and rifabutin, marketed by RedHill Biopharma Ltd.

Intellectual Property

Intellectual property, including patents, trade secrets, trademarks and copyrights, is important to our business. Our commercial success depends in significant part on our ability to obtain, maintain and enforce proprietary intellectual property protection for vonoprazan, as well as for any future product candidates, formulations, manufacturing processes and related know-how. Our commercial success also depends on our ability to operate without infringing the proprietary rights of third parties and to prevent others from infringing our proprietary rights.

Our intellectual property strategy is focused on protecting the compound vonoprazan and related technologies through a combination of licensed patent rights, regulatory exclusivities, trade secrets and trademarks.

Our patent portfolio covering vonoprazan consists predominantly of patents and patent applications that are exclusively licensed to us from Takeda pursuant to the license agreement we entered into on May 7, 2019, or the Takeda License. Under the Takeda License, we have exclusive rights in the United States, Europe and Canada to patents and patent applications covering the composition of matter, formulation, use and manufacture of vonoprazan, subject to the terms and conditions of the agreement. This patent portfolio comprises eleven distinct patent families protecting technology relating to vonoprazan and its synthetic intermediates, methods of synthesizing vonoprazan and related compounds, pharmaceutical formulations, and methods of treating diseases using vonoprazan and related compounds. As of December 31, 2025, our portfolio included approximately 26 issued U.S. patents and one pending U.S. patent application, 16 issued European patents validated in individual European countries and two pending European patent applications, and seven issued Canadian patents and two pending Canadian patent applications. The issued patents and pending applications in our portfolio have nominal expiration dates ranging from 2024 to 2038, without accounting for any patent term adjustments or extensions that may be available. We have received a patent term extension, or PTE,

10

of 607 days for the U.S. composition-of-matter patent covering the vonoprazan molecule based on the FDA approval of the New Drug Application, or NDA, for VOQUEZNA DUAL PAK. Patent term extensions under the Hatch-Waxman Act are granted on a product-specific basis and are limited to claims covering the approved product, a method of using such product, or a method of manufacturing such product. As a result, there can be no assurance that the scope of this PTE will be enforceable with respect to other approved products containing vonoprazan, including VOQUEZNA or VOQUEZNA TRIPLE PAK, or any future product candidates containing the vonoprazan molecule. Absent any such patent term extension, the issued U.S. patent covering the composition of matter of vonoprazan is expected to expire in August 2028, and the issued U.S. patent covering certain formulations of our vonoprazan products is expected to expire in August 2030. However, in May 2022, following FDA approval of VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK, products containing the active moiety vonoprazan received five years of NCE exclusivity, which was extended by an additional five years under the Generating Antibiotic Incentives Now Act, or GAIN Act, resulting in a total of ten years of regulatory exclusivity through May 3, 2032. In June 2025, following our Citizen Petition, the FDA updated the Orange Book to reflect that VOQUEZNA tablets, approved in November 2023 and containing the same active moiety, benefit from the same extended ten-year NCE exclusivity period through May 3, 2032.

Patent terms generally expire 20 years from the earliest effective filing date, subject to statutory adjustments or extensions. While we may seek additional patent term extensions where available, there can be no assurance that any such extensions will be granted or that their scope will provide meaningful additional protection. Similar extension mechanisms are available in certain foreign jurisdictions.

The patent positions of pharmaceutical companies are inherently uncertain and subject to challenge. Our licensed patents or other future patents may be challenged, narrowed, invalidated or circumvented, and third parties may assert blocking patents against us. In addition, because pharmaceutical development and regulatory review require significant time, certain patents may expire or have limited remaining term by the time a product is commercialized. If our patent or regulatory exclusivity protection is reduced or expires, our competitive position could be adversely affected.

Trade Secrets and Trademarks

In addition to patents, we rely on trade secrets, proprietary know-how and confidentiality agreements to protect aspects of our technology and business that are not patentable or that we elect not to patent. We require our employees, consultants and other collaborators to enter into confidentiality and, where applicable, invention assignment agreements. These agreements are intended to protect our proprietary information and assign to us rights in inventions developed during the course of such relationships. However, there can be no assurance that these agreements will provide adequate protection in all circumstances or prevent unauthorized disclosure or use of our trade secrets.

Further, we have filed for and have received trademark registrations for our company name “Phathom Pharmaceuticals” in the United States, European Union, and other foreign jurisdictions, and are pursuing trademark protection in certain other foreign jurisdictions.

License Agreement with Takeda Pharmaceutical Company Limited

On May 7, 2019, we and Takeda entered into the Takeda License, pursuant to which, Takeda granted us an exclusive, sublicensable (with Takeda’s reasonable consent) license under certain patents and know how relating to vonoprazan and owned or controlled by Takeda during the term of the Takeda License to commercialize vonoprazan products using specified formulations for all human therapeutic uses in the United States, Europe and Canada, and a non-exclusive license under such patents and know how to develop and manufacture such vonoprazan products anywhere in the world (subject to Takeda’s consent as to each country) for the purposes of commercializing the vonoprazan products in the United States, Europe and Canada. We granted Takeda a non-exclusive, royalty-free, sublicensable license under our rights in any patents and know-how that are necessary or useful to enable Takeda to develop and manufacture vonoprazan products anywhere in the world for the purposes of commercialization outside United States, Europe and Canada. We also granted Takeda an exclusive, royalty-free license under our rights in certain patents and know-how owned or controlled by us and necessary for the exploitation of vonoprazan products, in each case for Takeda to commercialize any vonoprazan product outside of the United States, Canada, and Europe and for purposes other than human therapeutic use.

During the term of the Takeda License, we and our affiliates are not permitted to commercialize any pharmaceutical product, other than vonoprazan, that treats acid-related disorders, except for certain generic and OTC competing products in specified circumstances. We will be responsible, at our cost, for the development, manufacture and commercialization of the vonoprazan

11

products. We are required to use commercially reasonable efforts to develop and commercialize the vonoprazan products in our licensed territory.

Under the Takeda License, Takeda has the sole right and authority, with our input, to prepare, file, prosecute, and maintain all Takeda and joint patents on a worldwide basis at its own cost. We are responsible, at our cost, for preparing, filing, prosecuting, and maintaining patents on inventions made solely by us in connection with vonoprazan, subject to input from Takeda. We have the first right to enforce the licensed patent rights with respect to certain infringing products in the United States, Europe and Canada.

We paid Takeda upfront consideration consisting of a cash payment of $25 million, 1,084,000 shares of common stock and a warrant to purchase 7,588,000 shares of common stock, or the Takeda Warrant. We agreed to make milestone payments to Takeda upon achieving certain tiered aggregate annual net sales of licensed products in the United States, Europe and Canada up to a total maximum milestone amount of $250 million. We also agreed to make tiered royalty payments averaging in the low double digits royalty rate on aggregate net sales of licensed products, subject to specified offsets and reductions. Royalties will be payable, on a product-by-product and country-by-country basis from the first commercial sale of such product in such country, until the latest of expiration of the licensed patents covering the applicable product, expiration of regulatory exclusivity in such country, or 15 years following first commercial sale in such country.

The Takeda License will continue until the expiration of the obligation to pay royalties in all countries and on all products. We may terminate the Takeda License in its entirety without cause upon six months’ prior written notice. We and Takeda may terminate the Takeda License in the case of the other party’s insolvency, or upon prior written notice within a specified time period for the other party’s material uncured breach. Takeda may terminate the Takeda License in its entirety if we challenge the licensed patents, or if we assist any third party in challenging such patents.

Manufacturing

We do not currently own or operate manufacturing facilities for the production of clinical or commercial quantities of vonoprazan. Vonoprazan is a small molecule that can be manufactured using commercially available technologies. We rely on third-party contract manufacturers to manufacture commercial and clinical quantities of our products, and expect to do so for any future product candidates. Although we rely on contract manufacturers, we have personnel with manufacturing experience to oversee our relationships with our suppliers, Evonik, Catalent and Sandoz.

Evonik Commercial Supply Agreement

In August 2022, we entered into a Commercial Supply Agreement, or the API Supply Agreement, with Evonik Operations GmbH, or Evonik, pursuant to which Evonik has agreed to supply us with commercial quantities of vonoprazan drug substance, or API.

Pursuant to the API Supply Agreement, Evonik has agreed to supply us with, and we have agreed to purchase certain quantities of API at an agreed upon price which varies based on the volume of product ordered. The price may also be adjusted based on actual changes in costs incurred by Evonik. Subject to pre-existing purchase obligations to Takeda, we have agreed to purchase a percentage of our annual requirements of API from Evonik, for which the percentage of our annual API requirements is subject to adjustment based upon the price of API under the API Supply Agreement.

Unless terminated earlier, the API Supply Agreement has an initial period that expires in August 2027. This initial term was extended by two years from 2027 to 2029 upon Evonik's successful qualification of a second manufacturing facility to produce API in December of 2024. The API Supply Agreement may be terminated effective at the end of the initial period on at least 24-months written notice by either party. In the absence of such notice, the API Supply Agreement will extend automatically for additional 2-year periods which may be terminated upon 18 months’ notice. The API Supply Agreement may also be terminated at any time upon written notice by either party if the other party has failed to remedy a material breach of the terms of the Supply Agreement within a specified period following receipt of written notice of such breach.

Catalent Commercial Supply Agreement

In July 2021, we entered into a Commercial Supply Agreement, or the Tablet Supply Agreement, with Catalent Pharma Solutions, LLC, or Catalent, pursuant to which Catalent has agreed to supply us with commercial quantities of vonoprazan fumarate tablets.

12

Pursuant to the Tablet Supply Agreement, as amended, Catalent has agreed to supply us with, and we have agreed to purchase from Catalent, finished vonoprazan tablets at an agreed upon price per unit. The price per unit may be adjusted annually based on increases in costs incurred by Catalent. The Tablet Supply Agreement requires us to purchase a specified percentage of our requirements of finished vonoprazan tablets from Catalent, which percentage is subject to adjustment following January 1, 2027.

Unless terminated earlier, the term of the Tablet Supply Agreement extends for a period of five years from the Commencement Date. The Tablet Supply Agreement will extend automatically for additional two year periods unless terminated by either party upon at least 24 months prior written notice. The Tablet Supply Agreement may also be terminated at any time upon written notice by either party if the other party has failed to remedy a material breach of the terms of the Tablet Supply Agreement within a specified period following receipt of written notice of such breach.

Sandoz Supply and Packaging Agreement

In December 2020, we entered into a Supply and Packaging Services Agreement with Sandoz GmbH, or the Sandoz Supply Agreement, pursuant to which Sandoz has agreed to supply commercial quantities of amoxicillin capsules and clarithromycin tablets, to package these antibiotics with vonoprazan drug product in finished convenience packs, and to supply us with these convenience packs.

Pursuant to the Sandoz Supply Agreement, we agreed to purchase certain quantities of convenience packs from Sandoz at an agreed upon price per pack. The price per pack is fixed for the first two (2) years following launch of the convenience pack in the United State and may be adjusted thereafter based on Sandoz’s cost increases, subject to an annual cap. The Sandoz Supply Agreement sets forth an annual minimum number of convenience packs that we must purchase each year following launch of the convenience pack product, and if we do not meet the minimum order in a given year, we are required to pay Sandoz the amount corresponding to the shortfall. Sandoz has no obligation to supply convenience packs above a maximum number of packs above a certain percentage of our forecasts. We have agreed to purchase convenience packs, amoxicillin capsules, and clarithromycin tablets, in each case intended for sale in the United States, exclusively from Sandoz during the five-year period following launch.

The Sandoz Supply Agreement will continue for five years from launch of the convenience pack in the U.S. and may be terminated effective at the end of the initial five-year term upon written notice by either party prior to the end of the third year following launch. In the absence of such notice, the Sandoz Supply Agreement will extend automatically for an additional three-year period, and thereafter as mutually agreed upon by the parties. The Sandoz Supply Agreement may also be terminated at any time upon written notice by either party for uncured material breach following written notice of such breach.

We had previously been informed by Sandoz that there could be a disruption in the supply of clarithromycin tablets, a component of the VOQUEZNA TRIPLE PAK, which could lead to a disruption in supply of VOQUEZNA TRIPLE PAKs. Given more recent communications, however, we do not currently anticipate any near-term disruptions. We plan to continue to actively monitor the situation to determine if a supply disruption may arise in the future. The VOQUEZNA TRIPLE PAK represented approximately 1% of our total revenue for 2025. While we have not experienced any commercial disruption to date, any disruption for such supply would result in our inability to continue to commercialize the VOQUEZNA TRIPLE PAK. The VOQUEZNA bottles and the VOQUEZNA DUAL PAKs are not impacted, as they do not include clarithromycin.

Government Regulation

Government authorities in the United States, at the federal, state and local level, and other countries extensively regulate, among other things, the research, development, testing, manufacture, quality control, approval, labeling, packaging, storage, record-keeping, promotion, advertising, distribution, marketing and export and import of products such as those we are developing. A new drug must be approved by the FDA through the NDA process before it may be legally marketed in the United States.

U.S. Drug Development Process

In the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act, or the FDCA, and its implementing regulations. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources.

The process required by the FDA before a drug may be marketed in the United States generally involves the following:

13

•
completion of certain preclinical laboratory tests, animal studies and formulation studies in accordance with Good Laboratory Practice, or GLP, regulations and other applicable regulations;

•
submission to the FDA of an investigational new drug application, or IND, which must become effective before human clinical trials may begin;

•
approval by an independent institutional review board, or IRB, at each clinical site before each trial may be initiated;

•
performance of adequate and well-controlled human clinical trials in accordance with Good Clinical Practice, or GCP, regulations to establish the safety and efficacy of the proposed drug for its intended use;

•
submission to the FDA of an NDA;

•
satisfactory completion of an FDA advisory committee review, if applicable;

•
satisfactory completion of an FDA inspection of the manufacturing facility or facilities at which the drug is produced to assess compliance with current Good Manufacturing Practice, or cGMP, requirements to assure that the facilities, methods and controls are adequate to preserve the drug’s identity, strength, quality and purity;

•
satisfactory completion of potential FDA inspection of selected clinical investigation sites to assess compliance with GCPs; and

•
FDA review and approval of the NDA to permit commercial marketing of the product for particular indications for use in the United States.

Once a pharmaceutical candidate is identified for development, it enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry, toxicity and formulation, as well as animal studies. The conduct of preclinical studies is subject to federal regulations and requirements, including GLP regulations for certain studies. Prior to beginning the first clinical trial with a product candidate in the United States, a sponsor must submit an IND to the FDA. The sponsor must submit the results of the preclinical tests, together with manufacturing information and analytical data, to the FDA as part of the IND, which is a request for allowance from the FDA to administer an investigational drug product to humans. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day time period, places the clinical trial on a full or partial clinical hold. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin, or with respect to a partial hold, begin as intended.

Clinical trials involve the administration of the investigational product to human subjects under the supervision of one or more qualified investigators in accordance with GCP regulations. Clinical trials are conducted under protocols detailing, among other things, the objectives of the trial, dosing procedures, subject selection and exclusion criteria and the safety and effectiveness criteria to be evaluated. Each protocol must be submitted to the FDA as part of the IND as well as any subsequent protocol amendments. While the IND is active, progress reports summarizing the results of the clinical trials and nonclinical studies performed since the last progress report, among other information, must be submitted at least annually to the FDA and written IND safety reports must be submitted to the FDA and investigators for serious and unexpected suspected adverse events, findings from other studies suggesting a significant risk to humans exposed to the drug, findings from animal or in vitro testing suggesting a significant risk to humans exposed to the drug, and any clinically important increased rate of a serious suspected adverse reaction compared to that listed in the protocol or investigator brochure.

Furthermore, an IRB at each institution participating in the clinical trial must review and approve each protocol before a clinical trial commences at that institution and must also approve the information regarding the trial and the consent form that must be provided to each trial subject or his or her legal representative, monitor the study until completed and otherwise comply with IRB regulations. The FDA or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the research subjects or patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the drug has been associated with unexpected serious harm to patients. In addition, some clinical trials are overseen by an independent group of qualified experts organized by the sponsor, known as a data safety monitoring board or committee. Depending on its charter, this group may determine whether a trial may move forward at designated check points based on access to certain data from the trial. There are also requirements governing the reporting of certain ongoing or completed clinical trial to clinicaltrials.gov.

14

Human clinical trials are typically conducted in three sequential phases that may overlap or be combined:

•
Phase 1: The product candidate is initially introduced into healthy human volunteers or patients with the target disease or condition. These studies test for safety, dosage tolerance, absorption, metabolism, distribution and excretion and, if possible, to gain an early indication of its effectiveness.

•
Phase 2: The product candidate is administered to a limited patient population with a specified disease or condition to evaluate the preliminary efficacy, optimal dosages and dosing schedule and to identify possible adverse side effects and safety risks.

•
Phase 3: The product candidate is administered to an expanded patient population to further evaluate dosage, to provide statistically significant evidence of the product’s effectiveness for its intended use(s) and to further test for safety, generally at multiple geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk-benefit ratio of the product candidate and provide, if appropriate, an adequate basis for product labeling.

Post-approval trials, sometimes referred to as Phase 4 studies, may be conducted after initial marketing approval. These trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication. In certain instances, the FDA may mandate the performance of Phase 4 clinical trials as a condition of approval of an NDA.

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the drug and finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the manufacturer must develop methods for testing the identity, strength, quality and purity of the final drug. In addition, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

NDA Review and Approval Process

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, preclinical and other non-clinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests conducted on the chemistry of the drug, proposed labeling and other relevant information are submitted to the FDA as part of an NDA requesting approval to market the product. The submission of an NDA is subject to the payment of substantial user fees; a waiver of such fees may be obtained under certain limited circumstances.

The FDA conducts a preliminary review of all NDAs within the first 60 days after submission, before accepting them for filing, to determine whether they are sufficiently complete to permit substantive review. Once filed, the FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether its manufacturing is cGMP-compliant to assure and preserve the product’s identity, strength, quality and purity. Under current PDUFA guidelines, the FDA has a goal of ten months from the date of “filing” of a standard NDA for a new molecular entity to review and act on the submission. This review typically takes twelve months from the date the NDA is submitted to FDA because the FDA has approximately two months to make a “filing” decision after the application is submitted.

The FDA may refer an application for a novel drug to an advisory committee. An advisory committee is a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and provides a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Before approving an NDA, the FDA will inspect the facility or facilities where the product is manufactured. Additionally, before approving an NDA, the FDA may inspect one or more clinical trial sites to assure compliance with GCP requirements.

After the FDA evaluates an NDA, it will issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the drug with prescribing information for specific indications. A Complete Response Letter indicates that the review cycle of the application is complete and the application will not be approved in its present form. A Complete Response Letter usually describes the specific deficiencies in the NDA identified by the FDA and may require additional clinical trials or other significant and time-consuming requirements related to clinical trials, nonclinical studies or manufacturing to support the application. If a Complete Response Letter is issued, the sponsor must resubmit the NDA, addressing all of the deficiencies identified

15

in the letter, or withdraw the application. Even if such data and information are submitted, the FDA may decide that the NDA does not satisfy the criteria for approval.

If a product receives regulatory approval, the approval may be significantly limited to specific diseases and dosages or the indications for use may otherwise be limited, which could restrict the commercial value of the product. In addition, the FDA may require a sponsor to conduct additional clinical studies to further assess a drug’s safety and effectiveness after NDA approval, and may require testing and surveillance programs to monitor the safety of approved products which have been commercialized. The FDA may also place other conditions on approval including the requirement for a risk evaluation and mitigation strategy, or REMS, to assure the safe use of the drug.

Furthermore, the Pediatric Research Equity Act, or PREA, requires a sponsor to conduct pediatric clinical trials for most drugs, for a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration. Under PREA, original NDAs and supplements must contain a pediatric assessment unless the sponsor has received a deferral or waiver. The required assessment must evaluate the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The sponsor or FDA may request a deferral of pediatric clinical trials for some or all of the pediatric subpopulations. The FDA must send a non-compliance letter to any sponsor that fails to submit the required assessment, fails to keep a deferral current or fails to submit a request for approval of a pediatric formulation.

Post-Approval Requirements

Once an approval is granted, the FDA may withdraw the approval if compliance with regulatory standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product may result in restrictions on the product or even complete withdrawal of the product from the market. After approval, some types of changes to the approved product, such as adding new indications, certain manufacturing changes and additional labeling claims, are subject to further FDA review and approval. Drug manufacturers and other entities involved in the manufacture and distribution of approved drugs are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP regulations and other laws and regulations. In addition, the FDA may impose a number of post-approval requirements as a condition of approval of an NDA. For example, the FDA may require post-marketing testing, and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization.

Any drug products manufactured or distributed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, record-keeping requirements, reporting of adverse experiences with the drug, providing the FDA with updated safety and efficacy information, drug sampling and distribution requirements, complying with certain electronic records and signature requirements, and complying with FDA promotion and advertising requirements. The FDA strictly regulates labeling, advertising, promotion and other types of information on products that are placed on the market and imposes requirements and restrictions on drug manufacturers, such as those related to direct-to-consumer advertising, the prohibition on promoting products for uses or in patient populations that are not described in the product’s approved labeling (known as “off-label use”), industry-sponsored scientific and educational activities, and promotional activities involving the Internet. Physicians may prescribe, in their independent professional medical judgment, legally available products for uses that are not described in the product’s labeling and that differ from those tested by us and approved by the FDA. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, restrict manufacturer’s communications on the subject of off-label use of their products. However, companies may share truthful and not misleading information that is otherwise consistent with a product’s FDA-approved labeling.

Discovery of previously unknown problems or the failure to comply with the applicable regulatory requirements may result in restrictions on the marketing of a product or withdrawal of the product from the market as well as possible civil or criminal sanctions. Failure to comply with the applicable U.S. requirements at any time during the product development process, approval process or post-approval, may subject an applicant or manufacturer to administrative or judicial civil or criminal sanctions and adverse publicity. FDA sanctions could include refusal to approve pending applications, withdrawal of an approval, clinical holds on post-approval clinical trials, warning or untitled letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, refusals of government contracts, mandated corrective advertising or communications with doctors, debarment, restitution, disgorgement of profits, or civil or criminal penalties.

16

Non-Patent Data and Market Exclusivity

Data and market exclusivity provisions under the FDCA can delay the submission or the approval of certain marketing applications. The FDCA provides a five-year period of non-patent data exclusivity within the United States to the first applicant to obtain approval of an NDA for a new chemical entity. A drug is a NCE if the FDA has not previously approved any other new drug containing the same active moiety, which is the molecule or ion responsible for the action of the drug substance. During the exclusivity period, the FDA may not accept for review an abbreviated new drug application, or ANDA, or an NDA submitted under Section 505(b)(2), or 505(b)(2) NDA, submitted by another company for another drug based on the same active moiety, regardless of whether the drug is intended for the same indication as the original innovative drug or for another indication, where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted after four years if it contains a certification of patent invalidity or non-infringement to one of the patents listed with the FDA by the innovator NDA holder.

The FDCA alternatively provides three years of non-patent market exclusivity for an NDA, or supplement to an existing NDA, if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example new indications, dosages or strengths of an existing drug. This three-year exclusivity covers only the modification for which the drug received approval on the basis of the new clinical investigations and does not prohibit the FDA from approving ANDAs or 505(b)(2) NDAs for drugs containing the active agent for the original indication or condition of use. Five-year and three-year exclusivity will not delay the submission or approval of a full NDA. However, an applicant submitting a full NDA would be required to conduct or obtain a right of reference to all of the preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.

Pediatric exclusivity is another type of market exclusivity available in the United States. Pediatric exclusivity provides for an additional six months of marketing exclusivity attached to another period of non-patent regulatory exclusivity or patent term if a sponsor conducts clinical trials in children in response to a written request from the FDA. The issuance of a written request does not require the sponsor to undertake the described clinical trials.

Additionally, under the GAIN Act, the FDA may designate a product as a QIDP. In order to receive this designation, a drug must qualify as an antibacterial or antifungal drug for human use intended to treat serious or life-threatening infections, including those caused by either (1) an antibacterial or antifungal resistant pathogen, including novel or emerging infectious pathogens, or (2) a so-called “qualifying pathogen” found on a list of potentially dangerous, drug-resistant organisms established and maintained by the FDA under the law. The FDA interprets QIDP designation to apply to a specific drug product, including a specific dosage form of the product. A sponsor must request such designation before submitting a marketing application, and the FDA will respond to a request for QIDP designation within 60 days of the date the FDA receives the request. The GAIN Act permits the FDA to revoke a QIDP designation if the request for such designation contained an untrue statement of material fact.

The benefits of QIDP designation include potential eligibility for priority review and Fast Track designation, and an extension by an additional five years of any non-patent exclusivity period awarded, such as a five-year NCE exclusivity period awarded for a new chemical entity. This extension is in addition to any pediatric exclusivity extension that may be awarded, and the extension will be awarded only to a drug first approved on or after the date of enactment. The GAIN Act provisions prohibit the grant of an exclusivity extension where the application is a supplement to an application for which an extension is in effect or has expired, is a subsequent application for a specified change to an approved product, or is an application for a product that does not meet a definition of QIDP based on the uses for which it is ultimately approved.

U.S. Healthcare Fraud and Abuse Laws and Compliance Requirements

In addition to FDA regulation of pharmaceutical products, U.S. federal and state healthcare laws and regulations restrict business practices in the pharmaceutical industry. These laws may impact, among other things, our current and future business operations, including our clinical research activities, and constrain the business or financial arrangements and relationships with healthcare providers and other parties. These laws include anti-kickback and false claims laws, civil monetary penalties laws, and transparency laws regarding drug pricing and payments or other items of value provided to physicians and other healthcare providers.

The federal Anti-Kickback Statute prohibits, among other things, individuals or entities from knowingly and willfully offering, paying, soliciting or receiving remuneration, directly or indirectly, overtly or covertly, in cash or in kind to induce or in return for purchasing, leasing, ordering or arranging for or recommending the purchase, lease or order of any item or service reimbursable

17

under Medicare, Medicaid or other federal healthcare programs. A person or entity does not need to have actual knowledge of this statute or specific intent to violate it in order to have committed a violation.

The federal civil and criminal false claims laws, including the civil False Claims Act, and civil monetary penalties laws prohibit, among other things, any individual or entity from knowingly presenting, or causing to be presented, a false claim for payment to the federal government, knowingly making, using or causing to be made or used a false record or statement material to a false or fraudulent claim to the federal government, or from knowingly making a false statement to avoid, decrease or conceal an obligation to pay money to the federal government. In addition, the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the civil False Claims Act.

The federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, created additional federal criminal statutes that prohibit, among other things, knowingly and willfully executing a scheme to defraud any healthcare benefit program, including private third-party payers and knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services. Similar to the U.S. federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation.

The federal civil monetary penalties laws, impose civil fines for, among other things, the offering or transfer of remuneration to a Medicare or state healthcare program beneficiary if the person knows or should know it is likely to influence the beneficiary’s selection of a particular provider, practitioner, or supplier of services reimbursable by Medicare or a state healthcare program, unless an exception applies.

The federal Physician Payments Sunshine Act requires certain manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program, with specific exceptions, to report annually to the Centers for Medicare & Medicaid Services, or CMS, information related to payments or other transfers of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), certain other non-physician practitioners (physician assistants, nurse practitioners, clinical nurse specialists, certified registered nurse anesthetists, anesthesiology assistants and certified nurse midwives), and teaching hospitals, and applicable manufacturers and applicable group purchasing organizations to report annually to CMS ownership and investment interests held by physicians and their immediate family members.

Similar state and local laws and regulations may also restrict business practices in the pharmaceutical industry, such as state anti-kickback and false claims laws, which may apply to business practices, including but not limited to, research, distribution, sales and marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payers, including private insurers, or by patients themselves; state laws that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government, or otherwise restrict payments that may be made to healthcare providers and other potential referral sources; state laws and regulations that require drug manufacturers to file reports relating to pricing and marketing information or which require tracking gifts and other remuneration and items of value provided to physicians, other healthcare providers and entities; and state and local laws that require the registration of pharmaceutical sales representatives.

Violation of any of such laws or any other governmental regulations that apply may result in significant criminal, civil and administrative penalties including damages, fines, imprisonment, disgorgement, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws, contractual damages, reputational harm, diminished profits and future earnings, disgorgement, exclusion from participation in government healthcare programs and the curtailment or restructuring of our operations.

U.S. Coverage and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any product candidate for which we may seek regulatory approval. Sales in the United States will depend, in part, on the availability of sufficient coverage and adequate reimbursement from third-party payers, which include government health programs such as Medicare, Medicaid, TRICARE and the Veterans Administration, as well as managed care organizations and private health insurers. Coverage and reimbursement for VOQUEZNA, VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK and any future product candidates can be subject to challenge, reduction or denial by third-party payers.

18

The process for determining whether a third-party payer will provide coverage for a product is typically separate from the process for setting the reimbursement rate that the payer will pay for the product. In the United States, there is no uniform policy among payers for coverage or reimbursement. Decisions regarding whether to cover a product, the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. Third-party payers often rely upon Medicare coverage policy and payment limitations in setting their own coverage and reimbursement policies, but also have their own methods and approval processes. Therefore, coverage and reimbursement for products can differ significantly from payer to payer. As a result, the coverage determination process is often a time-consuming and costly process that can require manufacturers to provide scientific and clinical support for the use of a product to each payer separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance.

Third-party payers are increasingly challenging the price and examining the medical necessity and cost-effectiveness of medical products and services, in addition to their safety and efficacy. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit sales of any product that receives approval. Third-party payers may not consider vonoprazan or any future product candidates to be medically necessary or cost-effective compared to other available therapies, or the rebate percentages required to secure favorable coverage may not yield an adequate margin over cost or may not enable us to maintain price levels sufficient to realize an appropriate return on our investment in drug development. Additionally, decreases in third-party reimbursement for any product or a decision by a third-party payer not to cover a product could reduce physician usage and patient demand for the product.

Medicaid is a joint federal and state program administered by the states for low-income and disabled beneficiaries. Medicare is a federal program that is administered by the federal government covering individuals age 65 and over as well as those with certain disabilities. Under the Medicaid Drug Rebate Program, or MDRP, as a condition of having federal funds being made available to the states for covered outpatient drugs under Medicaid, and, if applicable, Medicare Part B, pharmaceutical manufacturers must enter into an agreement with the Secretary of Health and Human Services to pay a rebate to state Medicaid programs for each unit of covered outpatient drug dispensed to a Medicaid beneficiary and paid for by the state Medicaid program. Medicaid drug rebates are based on pricing data that pharmaceutical manufacturers report on a monthly and quarterly basis to CMS, which is the federal agency that administers the MDRP and Medicare programs. For the MDRP, these data include the average manufacturer price, or AMP, for each drug and, in the case of innovator products, the Best Price, or BP, which represents the lowest price available from the manufacturer to any entity in the United States in any pricing structure, calculated to include all applicable sales and associated rebates, discounts and other price concessions. If a manufacturer becomes aware that its MDRP government price reporting submission for a prior quarter was incorrect or has changed as a result of recalculation of the pricing data, the manufacturer must resubmit the corrected data for up to three years after those data originally were due. If a manufacturer fails to provide information timely or is found to have knowingly submitted false information to the government, the manufacturer may be subject to civil monetary penalties and other sanctions, including termination from the MDRP.

Federal law requires that a manufacturer that participates in the MDRP also participate in the Public Health Service’s 340B drug pricing program, or the 340B program, in order for federal funds to be available for the manufacturer’s drugs under Medicaid and, if applicable, Medicare Part B. The 340B program is administered by the Health Resources and Services Administration, or HRSA, and requires participating manufacturers to agree to charge statutorily defined covered entities no more than the 340B “ceiling price” for the manufacturer’s covered outpatient drugs used in an outpatient setting. These 340B covered entities include a variety of community health clinics and other entities that receive health services grants from the Public Health Service, as well as hospitals that serve a disproportionate share of low-income patients. The 340B ceiling price is calculated using a statutory formula, which is based on the AMP and rebate amount for the covered outpatient drug as calculated under the MDRP. In general, products subject to Medicaid price reporting and rebate liability are also subject to the 340B ceiling price calculation and discount requirement. Manufacturers must report 340B ceiling prices to HRSA on a quarterly basis, and HRSA publishes them to 340B covered entities. HRSA has finalized regulations regarding the calculation of the 340B ceiling price and the imposition of civil monetary penalties on manufacturers that knowingly and intentionally overcharge covered entities for 340B‑eligible drugs. HRSA has also finalized an administrative dispute resolution process through which 340B covered entities may pursue claims against participating manufacturers for overcharges, and through which manufacturers may pursue claims against 340B covered entities for engaging in unlawful diversion or duplicate discounting of 340B drugs. In addition, legislation may be introduced that, if passed, would further expand the 340B program, such as adding further covered entities or requiring participating manufacturers to agree to provide 340B discounted pricing on drugs used in an inpatient setting.

In order to be eligible to have drug products paid for with federal funds under Medicaid and, if applicable, Medicare Part B, and purchased by certain federal agencies and grantees, a manufacturer must also participate in the U.S. Department of Veterans Affairs, or VA, Federal Supply Schedule, or FSS, pricing program. Under the VA/FSS program, a manufacturer must report the

19

Non-Federal Average Manufacturer Price, or Non-FAMP, for its covered drugs to the VA and charge certain federal agencies no more than the Federal Ceiling Price, which is calculated based on Non-FAMP using a statutory formula. These federal agencies are the VA, the U.S. Department of Defense, the U.S. Coast Guard, and the U.S. Public Health Service (including the Indian Health Service). The manufacturer must also pay rebates on products purchased by military personnel and dependents through the TRICARE retail pharmacy program.

We are enrolled or participate in the MDRP, the 340B program, the VA/FSS program, and the TRICARE retail pharmacy program, and have price reporting and payment obligations under these and other programs. Pricing and rebate calculations vary among products and programs. The calculations are complex and are often subject to interpretation by us, governmental or regulatory agencies, and the courts. We cannot ensure that any submissions we are required to make under these programs will not be found to be incomplete or incorrect.

Individual states continue to consider and have enacted legislation to limit the growth of healthcare costs, including the cost of prescription drugs and combination products. A number of states have either implemented or are considering implementation of drug price transparency legislation. Requirements under such laws include advance notice of planned price increases, reporting price increase amounts and factors considered by manufacturers in taking such increases, wholesale acquisition cost disclosure to prescribers, purchasers, and state agencies, and new product notice and reporting. Such legislation could limit the price or payment for certain drugs, and a number of states are authorized to impose civil monetary penalties or pursue other enforcement mechanisms against manufacturers who fail to comply with drug price transparency requirements, including the untimely, inaccurate, or incomplete reporting of drug pricing information.

U.S. Healthcare Reform

In the United States, there has been, and continues to be, several legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of product candidates, restrict or regulate post-approval activities, and affect the profitable sale of product candidates.

Among policy makers and payers in the United States, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality and/or expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives. In March 2010, the Patient Protection and Affordable Care Act, or the Affordable Care Act, was passed, which substantially changed the way healthcare is financed by both governmental and private insurers, and significantly affected the pharmaceutical industry. The Affordable Care Act increased the minimum level of Medicaid rebates payable by manufacturers of brand name drugs from 15.1% to 23.1%; required collection of rebates for drugs paid by Medicaid managed care organizations; imposed a non-deductible annual fee on pharmaceutical manufacturers or importers who sell certain “branded prescription drugs” to specified federal government programs; implemented a new methodology by which rebates owed by manufacturers under the MDRP are calculated for drugs that are inhaled, infused, instilled, implanted, or injected; expanded eligibility criteria for Medicaid programs; created a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with funding for such research; and established a Center for Medicare and Medicaid Innovation at the CMS to test innovative payment and service delivery models to lower Medicare and Medicaid spending, potentially including prescription drug spending.

Since its enactment, there have been judicial and political challenges to certain aspects of the Affordable Care Act. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the Affordable Care Act without specifically ruling on the constitutionality of the Affordable Care Act. Thus, the Affordable Care Act will remain in effect in its current form.

In addition, other legislative changes have been proposed and adopted since the Affordable Care Act was enacted. For example, beginning April 1, 2013, Medicare payments to providers were reduced under the sequestration required by the Budget Control Act of 2011, which will remain in effect through 2032, unless additional Congressional action is taken. Additionally, on January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, further reduced Medicare payments to several providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. On March 11, 2021, the American Rescue Plan Act of 2021 was signed into law, which eliminated the statutory cap on manufacturers' Medicaid drug rebate liability, beginning January 1, 2024. Previously, the rebate was capped at 100% of a drug’s AMP.

20

Moreover, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for pharmaceutical products.

On August 16, 2022, the Inflation Reduction Act of 2022, or IRA, was signed into law. Among other things, the IRA requires manufacturers of certain drugs to engage in price negotiations with Medicare, with prices that can be negotiated subject to a cap; imposes rebates under Medicare Part B and Medicare Part D to penalize price increases that outpace inflation (first due in 2023); and replaced the Part D coverage gap discount program with a new discounting program (which began in 2025). The IRA permits the Secretary of the Department of Health and Human Services, or HHS, to implement many of these provisions through guidance, as opposed to regulation, for the initial years. HHS has and will continue to issue and update guidance as these programs are implemented. CMS has published the negotiated prices for the initial ten drugs, which went into effect in 2026, and the subsequent 15 drugs, which will first be effective in 2027, as well as the next set of 15 drugs that will be subject to negotiation, although the program is currently subject to legal challenges. The impact of the IRA on the pharmaceutical industry cannot yet be fully determined, but is likely to be significant.

The One Big Beautiful Bill Act, which was enacted in July 2025, imposes significant reductions in the funding of the Medicaid program. Such reductions are expected to decrease the number of persons enrolled in Medicaid and reduce the services covered by Medicaid, which could adversely affect our sales of VOQUEZNA, VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK or any other product candidate that we commercialize.

The Trump administration is pursuing a two-fold strategy to reduce drug costs in the U.S. President Trump has threatened to impose significant tariffs on pharmaceutical manufacturers that do not adopt pricing policies such as most favored nation pricing, which would tie the price for drugs in the U.S. to the lowest price in a group of other countries. In response, multiple manufacturers have reportedly entered into confidential pricing agreements with the federal government. The Trump administration is also pursuing traditional regulatory pathways to impose drug pricing policies, and published two proposed regulations in December 2025, referred to as Globe and Guard. If finalized, these regulations would implement mandatory payment models under which manufacturers of eligible drugs would be required to pay rebates to the federal government on a portion of the units of their drugs that are reimbursed by Medicare, with the rebate amount based on most favored nation pricing. While the impact of the Globe and Guard proposed regulations, if finalized, cannot yet be determined, it could be significant. Even regulatory proposals or executive actions that are ultimately deemed unlawful could negatively impact the U.S. pharmaceutical sector and our business. In addition, pharmaceutical pricing and marketing has long been the subject of considerable discussion in Congress and among policymakers, and it is possible that Congress could enact additional laws that negatively affect the pharmaceutical industry.

Individual states in the U.S. have also become increasingly active in implementing regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure, drug price reporting and other transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Some states have enacted legislation creating so-called prescription drug affordability boards, which ultimately may attempt to impose price limits on certain drugs in these states. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine which drugs and suppliers will be included in their healthcare programs. Furthermore, there has been increased interest by third-party payers and governmental authorities in reference pricing systems and publication of discounts and list prices.

The likelihood of implementation of additional reform initiatives is uncertain. Moreover, in the coming years, additional legislative and regulatory changes could be made to governmental health programs that could significantly impact pharmaceutical companies and the success of our product candidates.

Foreign Regulation

In order to market any product outside of the United States, we would need to comply with numerous and varying regulatory requirements of other countries and jurisdictions regarding quality, safety and efficacy and governing, among other things, clinical trials, marketing authorization, commercial sales and distribution of our products. Whether or not we obtain FDA approval for a product, we would need to obtain the necessary approvals by the comparable foreign regulatory authorities before we can commence clinical trials or marketing of the product in foreign countries and jurisdictions. Although many of the issues discussed above with respect to the United States apply similarly in the context of the European Union, or EU, the approval process varies between countries and jurisdictions and can involve additional product testing and additional administrative review periods. The

21

time required to obtain approval in other countries and jurisdictions might differ from and be longer than that required to obtain FDA approval. Regulatory approval in one country or jurisdiction does not ensure regulatory approval in another, but a failure or delay in obtaining regulatory approval in one country or jurisdiction may negatively impact the regulatory process in others.

Regulation and Procedures Governing Marketing Authorization of Medicinal Products in the EU

Non-Clinical Studies and Clinical Trials

Similarly, to the United States, the various phases of non-clinical and clinical research in the EU are subject to significant regulatory controls.

Non-clinical studies are performed to demonstrate the health or environmental safety of new chemical or biological substances. Non-clinical (pharmaco-toxicological) studies must be conducted in compliance with the principles of good laboratory practice, or GLP, as set forth in EU Directive 2004/10/EC (unless otherwise justified for certain particular medicinal products, e.g., radio-pharmaceutical precursors for radio-labeling purposes). In particular, non-clinical studies, both in vitro and in vivo, must be planned, performed, monitored, recorded, reported and archived in accordance with the GLP principles, which define a set of rules and criteria for a quality system for the organizational process and the conditions for non-clinical studies. These GLP standards reflect the Organization for Economic Co-operation and Development requirements.

Clinical trials of medicinal products in the EU must be conducted in accordance with EU and national regulations and the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use, or ICH, guidelines on good clinical practices, or GCP, as well as the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki. If the sponsor of the clinical trial is not established within the EU, it must appoint an EU entity to act as its legal representative. The sponsor must take out a clinical trial insurance policy, and in most EU member states, the sponsor is liable to provide ‘no fault’ compensation to any study subject injured in the clinical trial.

The regulatory landscape related to clinical trials in the EU has been subject to recent changes. The EU Clinical Trials Regulation, or CTR, which was adopted in April 2014 and repeals the EU Clinical Trials Directive, became applicable on January 31, 2022. Unlike directives, the CTR is directly applicable in all EU member states without the need for member states to further implement it into national law. The CTR notably harmonizes the assessment and supervision processes for clinical trials throughout the EU via a Clinical Trials Information System, which contains a centralized EU portal and database.

While the EU Clinical Trials Directive required a separate clinical trial application, or CTA, to be submitted in each member state in which the clinical trial takes place, to both the competent national health authority and an independent ethics committee, much like the FDA and IRB, respectively, the CTR introduces a centralized process and only requires the submission of a single application for multi-center trials. The CTR allows sponsors to make a single submission to both the competent authority and an ethics committee in each member state, leading to a single decision per member state. The CTA must include, among other things, a copy of the trial protocol and an investigational medicinal product dossier containing information about the manufacture and quality of the medicinal product under investigation.

The assessment procedure of the CTA has been harmonized as well, including a joint assessment by all member states concerned, and a separate assessment by each member state with respect to specific requirements related to its own territory, including ethics rules. Each member state’s decision is communicated to the sponsor via the centralized EU portal. Once the CTA is approved, clinical study development may proceed.

The CTR foresees a three-year transition period. The extent to which ongoing and new clinical trials will be governed by the CTR varies. Clinical trials for which an application was submitted (i) prior to January 31, 2022 under the EU Clinical Trials Directive, or (ii) between January 31, 2022 and January 31, 2023 and for which the sponsor has opted for the application of the EU Clinical Trials Directive remain governed by said Directive until January 31, 2025. After this date, all clinical trials (including those which are ongoing) will become subject to the provisions of the CTR.

Medicines used in clinical trials must be manufactured in accordance with Good Manufacturing Practice, or GMP. Other national and EU-wide regulatory requirements may also apply.

Marketing Authorizations

22

In the EU, medicinal product candidates can only be commercialized after obtaining a marketing authorization, or MA. To obtain regulatory approval of a product candidate in the EU, we must submit a MA Application, or MAA. The process for doing this depends, among other things, on the nature of the medicinal product.

There are two types of MAs:

•
"Centralized MAs" are issued by the European Commission through the centralized procedure, based on the opinion of the Committee for Medicinal Products for Human Use, or CHMP, of the European Medicines Agency, or EMA, and are valid throughout the EU. The centralized procedure is mandatory for certain types of products, such as (i) medicinal products derived from biotechnological processes, (ii) designated orphan medicinal products, (iii) advanced therapy medicinal products, or ATMPs, such as gene therapy, somatic cell-therapy or tissue-engineered medicines and (iv) medicinal products containing a new active substance indicated for the treatment of certain diseases, such as HIV/AIDS, cancer, neurodegenerative diseases, diabetes, auto-immune and other immune dysfunctions and viral diseases. The centralized procedure is optional for any products containing a new active substance not yet authorized in the EU, or for products that constitute a significant therapeutic, scientific or technical innovation or for which the granting of a MA would be in the interest of public health in the EU.

•
"National MAs" are issued by the competent authorities of the EU member states, only cover their respective territory, and are available for product candidates not falling within the mandatory scope of the centralized procedure. Where a product has already been authorized for marketing in an EU member state, this national MA can be recognized in another member state through the mutual recognition procedure. If the product has not received a national MA in any member state at the time of application, it can be approved simultaneously in various member states through the decentralized procedure. Under the decentralized procedure an identical dossier is submitted to the competent authorities of each of the member states in which the MA is sought, one of which is selected by the applicant as the reference member state.

Under the above described procedures, before granting the MA, the EMA or the competent authorities of the EU member states make an assessment of the risk-benefit balance of the product on the basis of scientific criteria concerning its quality, safety and efficacy.

MAs have an initial duration of five years. After these five years, the authorization may be renewed for an unlimited period on the basis of a reevaluation of the risk-benefit balance. Under the centralized procedure the maximum timeframe for the evaluation of an MAA by the EMA is 210 days, excluding clock stops. In exceptional cases, the CHMP might perform an accelerated review of a MA in no more than 150 days (not including clock stops).

Data and marketing exclusivity

The EU also provides opportunities for market exclusivity. Upon receiving MA, innovative medicinal products generally receive eight years of data exclusivity and an additional two years of market exclusivity. If granted, the data exclusivity period prevents generic or biosimilar applicants from relying on the pre-clinical and clinical trial data contained in the dossier of the reference product when applying for a generic or biosimilar MA in the EU during a period of eight years from the date on which the reference product was first authorized in the EU. The market exclusivity period prevents a successful generic or biosimilar applicant from commercializing its product in the EU until 10 years have elapsed from the initial MA of the reference product in the EU. The overall 10-year market exclusivity period can be extended to a maximum of eleven years if, during the first eight years of those 10 years, the MA holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to their authorization, are held to bring a significant clinical benefit in comparison with existing therapies. However, there is no guarantee that a product will be considered by the EU’s regulatory authorities to be a new chemical (or biological) entity, and products may not qualify for data exclusivity.

Pediatric investigation plan

In the EU, MAAs for new medicinal products have to include the results of trials conducted in the pediatric population, in compliance with a pediatric investigation plan, or PIP, agreed with the EMA’s Pediatric Committee, or PDCO. The PIP sets out the timing and measures proposed to generate data to support a pediatric indication of the drug for which MA is being sought. The PDCO can grant a deferral of the obligation to implement some or all of the measures of the PIP until there are sufficient data to demonstrate the efficacy and safety of the product in adults. Further, the obligation to provide pediatric clinical trial data can be waived by the PDCO when these data are not needed or appropriate because the product is likely to be ineffective or unsafe in

23

children, the disease or condition for which the product is intended occurs only in adult populations, or when the product does not represent a significant therapeutic benefit over existing treatments for pediatric patients. Once the MA is obtained in all EU member states and study results are included in the product information, even when negative, the product is eligible for six months’ supplementary protection certificate extension (if any is in effect at the time of approval) or, in the case of orphan pharmaceutical products, a two-year extension of the orphan market exclusivity is granted.

Post-Approval Requirements

Similar to the United States, both MA holders and manufacturers of medicinal products are subject to comprehensive regulatory oversight by the EMA, the European Commission and/or the competent regulatory authorities of the member states. The holder of a MA must establish and maintain a pharmacovigilance system and appoint an individual qualified person for pharmacovigilance, or QPPV, who is responsible for the establishment and maintenance of that system, and oversees the safety profiles of medicinal products and any emerging safety concerns. Key obligations include expedited reporting of suspected serious adverse reactions and submission of periodic safety update reports, or PSURs.

All new MAAs must include a risk management plan, or RMP, describing the risk management system that we will put in place and documenting measures to prevent or minimize the risks associated with the product. The regulatory authorities may also impose specific obligations as a condition of the MA. Such risk-minimization measures or post-authorization obligations may include additional safety monitoring, more frequent submission of PSURs, or the conduct of additional clinical trials or post-authorization safety studies.

The advertising and promotion of medicinal products is also subject to laws concerning promotion of medicinal products, interactions with physicians, misleading and comparative advertising and unfair commercial practices. All advertising and promotional activities for the product must be consistent with the approved summary of product characteristics, and therefore all off-label promotion is prohibited. Direct-to-consumer advertising of prescription medicines is also prohibited in the EU. Although general requirements for advertising and promotion of medicinal products are established under EU directives, the details are governed by regulations in each member state and can differ from one country to another.

Failure to comply with the aforementioned EU and member state laws may result in administrative, civil or criminal penalties. These penalties could include delays or refusal to authorize the conduct of clinical trials, or to grant MA, product withdrawals and recalls, product seizures, suspension, withdrawal or variation of the MA, total or partial suspension of production, distribution, manufacturing or clinical trials, operating restrictions, injunctions, suspension of licenses, fines and criminal penalties.

The aforementioned EU rules are generally applicable in the European Economic Area, or EEA, which consists of the 27 EU member states plus Norway, Liechtenstein and Iceland.

Coverage and Reimbursement

Outside of the United States, the pricing of pharmaceutical products and medical devices is subject to governmental control in many countries. In the EU, pricing and reimbursement schemes vary widely from country to country. Some countries provide that products may be marketed only after a reimbursement price has been agreed. Some countries may require the completion of additional studies that compare the cost effectiveness of a particular therapy to currently available therapies or so-called health technology assessments, in order to obtain reimbursement or pricing approval. Other countries may allow companies to fix their own prices for products, but monitor and control product volumes and issue guidance to physicians to limit prescriptions. Efforts to control prices and utilization of pharmaceutical products and medical devices will likely continue as countries attempt to manage healthcare expenditures. Historically, products launched in the EU do not follow price structures of the United States and generally prices tend to be significantly lower.

Data Privacy and Security Laws

As a pharmaceutical company, we are subject to numerous federal, state and foreign data privacy, cybersecurity and data breach notification laws governing the collection, use, disclosure and protection of health-related and other personal information. These laws could apply now or in the future to our operations or the operations of our partners. In the U.S., numerous federal and state laws and regulations, including data breach notification laws, health information privacy and security laws and consumer protection laws and regulations (such as the California Consumer Privacy Act, or the CCPA) and similar state comprehensive data privacy laws in other states) govern the privacy and security of personal information, including health-related information. In addition, certain foreign laws such as the European Union General Data Protection Regulation, or the EU GDPR, and the United

24

Kingdom General Data Protection Regulation and Data Protection Act 2018, or collectively, the UK GDPR (the EU GDPR and UK GDPR together referred to as the GDPR) govern the privacy and security of personal data, including health-related data. Privacy and security laws, regulations, and other obligations are constantly evolving, may conflict with each other to complicate compliance efforts, and can result in investigations, proceedings, or actions that lead to significant civil and/or criminal penalties and restrictions on data processing.

Human Capital

As of December 31, 2025, we had 371 full-time employees, some of whom hold a Ph.D., M.D. or other advanced degree in their field. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and developing our existing and new employees, advisors and consultants. We maintain equity and cash incentive plans for, and offer a comprehensive benefit package to, every employee to attract, retain and reward personnel. The purpose of our cash and equity compensation plans is to increase stockholder value and the success of our company by motivating our employees to perform to the best of their abilities and achieve our objectives.

Corporate Information

We were originally incorporated under the laws of the state of Delaware on January 9, 2018 under the name North Bridge IV, Inc. On March 13, 2019, we changed our name to Phathom Pharmaceuticals, Inc. and merged YamadaCo IIA, Inc., a Delaware corporation, or YamadaCo, with and into our company, with Phathom Pharmaceuticals, Inc. as the surviving entity, or the Merger. Our principal executive offices are located at 100 Campus Drive, Suite 102, Florham Park, New Jersey 07932, and our telephone number is (877) 742-8466.

Available Information

Our internet address is www.phathompharma.com. Our investor relations website is located at https://investors.phathompharma.com. We make available free of charge on our investor relations website under “Financials and Filings” our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, our directors’ and officers’ Section 16 reports and any amendments to those reports as soon as reasonably practicable after filing or furnishing such materials to the SEC. They are also available for free on the SEC’s website at www.sec.gov.

We use our investor relations website as a means of disclosing material non-public information and for complying with our disclosure obligations under Regulation FD. Investors should monitor such website, in addition to following our press releases, SEC filings and public conference calls and webcasts. Information relating to our corporate governance is also included on our investor relations website. The information in or accessible through the SEC and our website are not incorporated into, and are not considered part of, this filing.

25