Altimmune, Inc. (ALT) Business

Item 1. Business

Overview

Altimmune, Inc. is a late clinical-stage biopharmaceutical company developing novel therapies for serious liver diseases. Our lead product candidate, pemvidutide (formerly known as ALT-801), is a balanced 1:1 glucagon/GLP-1 dual receptor agonist in development for the treatment of metabolic dysfunction-associated steatohepatitis (“MASH”), alcohol use disorder (“AUD”) and alcohol-associated liver disease (“ALD”). We may also pursue additional indications for pemvidutide that leverage its differentiated clinical profile. Except where the context indicates otherwise, references to “we,” “us,” “our,” “Altimmune”, or the “Company” refer to the company and its subsidiaries.

Pemvidutide

We obtained pemvidutide as part of the acquisition Spitfire Pharma Inc., in July of 2019. Pemvidutide was designed as a MASH therapeutic based on the understanding that targeting both metabolic and liver-specific effects could lead to an improved and differentiated candidate. Early work provided compelling preclinical efficacy data obtained from a mouse model of MASH. Following a first-in-human clinical trial where we observed initial signs of weight loss and pronounced liver effects, we evaluated pemvidutide in participants with fatty liver disease, or metabolic-dysfunction associated liver disease (MASLD), where we observed robust reductions in liver fat content and weight loss. These results confirmed the earlier study and paved the way for the biopsy-driven IMPACT Phase 2b trial in MASH. To better characterize the quality of the weight loss and cardiometabolic effects of pemvidutide, the MOMENTUM Phase 2 trial in overweight and obese participants was conducted and showed significant weight loss characterized by relative sparing of  lean muscle mass and improvements in serum lipids associated with cardiovascular disease. In addition to the recently completed IMPACT trial, pemvidutide is currently being evaluated in participants with AUD and, separately, ALD. There is evidence that pemvidutide may decrease the craving for alcohol in these individuals, with the added benefit that pemvidutide may reverse the harmful effects that alcohol has on the liver in these patients.

Pemvidutide is a novel, investigational peptide with balanced 1:1 glucagon/GLP-1 dual receptor agonist activity in clinical development for the treatment of MASH, AUD and ALD. We believe pemvidutide is the only glucagon/GLP-1 dual receptor agonist with a balanced 1:1 potency at glucagon and the GLP-1 receptors, in effect placing glucagon activity on an even footing with GLP-1 activity. The activation of glucagon receptors results in direct effects on the liver, including reductions in liver fat, inflammation and fibrosis, whereas the activation of GLP-1 receptors mediates suppression of appetite and reduction of cravings as well as metabolic effects such as weight loss.

Pemvidutide mechanism of action

ALD

5

Table of Contents

As of December 31, 2025, over 700 patients have been exposed to pemvidutide in 8 completed studies and 2 ongoing studies. In clinical trials to date, pemvidutide has demonstrated rapid reductions in liver fat, markers of liver inflammation, and early MASH resolution along with improvements in non-invasive tests (“NITs”) such as Enhanced Liver Fibrosis (“ELF”) score and Liver Stiffness Measurement (“LSM”) demonstrating antifibrotic activity. In addition, pemvidutide has shown clinically meaningful weight loss while exhibiting class-leading lean mass preservation. Pemvidutide has also shown a favorable tolerability and safety profile in clinical trials to date. Based on the clinical data we have accumulated, we believe pemvidutide may be able to address several serious liver diseases, and pemvidutide has received Breakthrough Therapy Designation for MASH from the FDA based on data obtained from IMPACT trial at 24 weeks, indicating it has shown early clinical evidence of substantial improvement over existing therapies.

Pemvidutide is protected by a robust patent portfolio covering its composition, formulation, methods of use and treatment with patent expiration dates extending into the 2040s when the expected patent term extension is included.

MASH

MASH is caused by multiple metabolic pathways that lead to an abnormal accumulation of liver fat, toxic lipid metabolites, and inflammation, that leads to liver fibrosis and increased risk of death due to cardiovascular disease and liver failure. Accumulating clinical evidence suggests that reduction in liver fat and liver inflammation is associated with MASH resolution and improvement in liver fibrosis. Furthermore, considering 80-90% of individuals with MASH are also overweight, we believe that combining a direct liver acting mechanism with weight loss could provide a compelling treatment for MASH patients. In recognition of pemvidutide’s potential differentiating benefits, the U.S. Food and Drug Administration (“FDA”) has granted both Breakthrough Therapy Designation and Fast Track designation to pemvidutide for the treatment of MASH.

IMPACT Phase 2b MASH Trial – 24 Week Results

On June 26, 2025, we released 24-week topline efficacy results from the IMPACT Phase 2b trial of pemvidutide in MASH and subsequently published those results in the journal Lancet (Noureddin M., et al., Lancet. 2025 Dec 6;406(10520):2644-2655). The Phase 2b trial enrolled 212 subjects with biopsy-confirmed MASH and fibrosis stages F2/F3 with and without diabetes randomized 1:2:2 to receive weekly subcutaneous doses of pemvidutide at 1.2 mg, 1.8 mg or placebo.

In an intent-to-treat (“ITT”) analysis, in which subjects with missing biopsies were considered non-responders, the proportions of subjects achieving MASH resolution without worsening of fibrosis at 24 weeks were 58.2% and 52.1%, for pemvidutide 1.2 mg and 1.8 mg, respectively versus 19.9% for placebo (p 0.0001 both doses). The effects on fibrosis improvement without worsening of MASH in an ITT analysis were 32.6% and 35.7% for pemvidutide 1.2 mg and 1.8 mg, respectively compared with 27.9% for placebo (differences not statistically significant). A supplemental AI-based analysis demonstrated statistically significant reductions in fibrosis, including 31% of subjects receiving pemvidutide 1.8 mg achieving a 60% or more reduction in fibrosis compared to 8% receiving placebo (p 0.001). Statistically significant changes in well-established non-invasive tests (“NITs”) of fibrosis, including Enhanced Liver Fibrosis (“ELF”) score and Liver Stiffness Measurement (“LSM”) were also observed compared with placebo at both doses. Together, these data suggest strong evidence of MASH resolution and anti-fibrotic activity of pemvidutide in the MASH population after 24 weeks of treatment.

6

Table of Contents

Pemvidutide Demonstrates Statistically Significant MASH Resolution at 24 Weeks

Note: **** indicates p0.0001 vs. placebo (Chi-Square Test). 1. For ITT Analysis, patients without a biopsy at 24 weeks, or those who did not complete treatment, are treated as non-responders. 2. NS vs. placebo (Chi-Square Test).

Pemvidutide also demonstrated a favorable safety and tolerability profile, with low overall treatment discontinuation rates due to adverse events of less than 1% and 1.2% in the pemvidutide 1.2 mg and 1.8 mg groups versus 2.4% in the placebo group, despite that no dose titration was used in the trial. There were no serious adverse events related to study medication.

IMPACT Phase 2b MASH Trial – 48 Week Results

On December 19, 2025, we announced positive 48-week topline results from the IMPACT Phase 2b trial of pemvidutide in patients with MASH.

The topline 48-week data from the IMPACT trial, which, by design, did not include histological readout, showed that treatment with pemvidutide achieved statistically significant improvements across treatment arms versus placebo in the key anti-fibrosis NITs of ELF and LSM. Importantly, these data exhibited continued reductions from week 24 in multiple tests including ELF and LSM and provide evidence of improvement in antifibrotic activity. These are well-established markers of fibrosis and are strongly associated with histological changes and liver related events. At 48 weeks, mean weight loss in pemvidutide-treated subjects was observed at the 1.2 mg and 1.8 mg doses, respectively, with no evidence of plateauing in the 1.8mg dose group. The 48-week data also maintained the favorable tolerability profile seen at 24 weeks, including a lower discontinuation rate due to adverse events versus placebo.

A summary of the 48-week topline results is provided below:

7

Table of Contents

8

Table of Contents

In December 2025, we held an End-of-Phase 2 meeting with the FDA to discuss and align on the parameters for a registrational Phase 3 trial of pemvidutide for MASH patients with moderate to advanced fibrosis with biopsy driven endpoints. The FDA provided feedback on trial design, endpoints, and agreed to the use of AIM-MASH AI Assist, the first FDA-qualified AI pathology tool for MASH clinical trials, in our Phase 3 trial. We received final minutes from the End-of-Phase 2 meeting in January 2026, which we believe describe a clear regulatory path for a Phase 3 trial in MASH. We are also in the process of seeking scientific advice from European regulators to further inform the final Phase 3 protocol.

Based on the clinical data obtained from the IMPACT trial and FDA feedback, we are currently preparing to initiate a pivotal, 52-week, Phase 3 clinical trial in MASH in 2026. The registrational program is expected to assess clinical data in support of our key differentiators in MASH including:

Additional Pemvidutide Indications

On March 13, 2025, we announced that we are pursuing AUD and ALD as additional indications for our lead product candidate, pemvidutide.

AUD

AUD is a chronic disease characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences. In addition to the underlying alcohol misuse by AUD patients, AUD patients have comorbidities that pose significant treatment and management challenges (including liver steatosis, overweight, obesity, hypertension and hyperlipidemia). It has been shown that therapies with GLP-1 activity may share neural mechanisms of food and alcohol reward systems and real-world evidence has suggests that the use of GLP-1-containing therapies reduces alcohol consumption. We have conducted a preclinical study of a hamster free-choice model in which pemvidutide demonstrated a maximum decrease of 82% in alcohol intake relative to vehicle controls. The excess alcohol consumption associated with AUD also often leads to an increase in liver fat, i.e., steatotic liver disease. We believe reducing alcohol consumption combined with improving liver health through the effects of glucagon would provide AUD patients with a compelling treatment option.

9

Table of Contents

On May 19, 2025, we announced the enrollment of the first subject in the RECLAIM Phase 2 trial evaluating the efficacy and safety of pemvidutide in subjects with AUD. RECLAIM is a randomized, placebo-controlled trial conducted across approximately 15 sites in the United States, targeting enrollment of approximately 100 subjects. Subjects will be randomized 1:1 to receive either 2.4 mg pemvidutide or placebo weekly for 24 weeks. The trial’s primary endpoint is a change in alcohol consumption, measured by the change from baseline in the average number of heavy drinking days per week measured at Week 24, with the key secondary endpoints including the proportion of subjects achieving a 2-level reduction in World Health Organization (“WHO”) risk drinking level and the absolute change from baseline in average levels of phosphatidylethanol (“PEth”), a serum biomarker of alcohol intake.

On August 19, 2025, we announced that the U.S. Food and Drug Administration has granted Fast Track designation to pemvidutide for the treatment of AUD. Fast Track designation is intended to accelerate the development and review of new drugs that target serious conditions and address unmet medical needs.

On November 3, 2025, we announced the completion of enrollment in the RECLAIM Phase 2 trial. Enrollment completed ahead of schedule, underscoring strong interest from the patient community in a new therapeutic option for AUD. We are on track to complete the 24-week treatment period and announce topline results in 2026.

ALD

ALD is a disease characterized by damage to the liver due to excessive and chronic alcohol use. ALD progression (like MASH progression) begins with liver steatosis, which may lead to inflammation, fibrosis and, ultimately, to cirrhosis. Given the progression of the disease, ALD is one of the leading cause of liver transplants in the US. Unfortunately, there are currently no approved treatments for ALD.

On July 9, 2025, we announced the enrollment of the first patient in the RESTORE Phase 2 trial evaluating the efficacy and safety of pemvidutide in subjects with ALD. RESTORE is a randomized, placebo-controlled trial enrolling approximately 100 patients across 34 sites in the United States. Subjects will be randomized 1:1 to receive either 2.4mg pemvidutide or placebo weekly for 48 weeks. The trial’s primary endpoint is the change from baseline in LSM by vibration-controlled transient elastography (“VCTE”) at Week 24. Key secondary endpoints include the change from baseline in LSM by VCTE at Week 48, changes in ELF score at Weeks 24 and 48, and changes in alcohol consumption and body weight at the same time points.

10

Table of Contents

Our Strategy

Our goal is to become a leading biopharmaceutical company offering innovative treatments for serious liver diseases. Key elements of our strategy include the following:

Competition

The biopharmaceutical industry is intensely competitive and is characterized by rapid technological progress. In general, competition among pharmaceutical products is based in part on product efficacy, safety, reliability, availability, price and patent position. An important factor is the relative timing of the market introduction of our products and our competitors’ products. Accordingly, the speed with which we can develop products, complete the clinical trials and approval processes and supply commercial quantities of the products to the market is an important competitive factor. Our competitive position also depends upon our ability to show differentiation with a product that is either more efficacious, particularly in the relevant target populations, offers a better safety or tolerability profile, is less expensive or quicker to manufacture, or represents a combination of these advantages. We also depend upon our ability to attract and retain qualified personnel, obtain patent protection or otherwise develop proprietary products or processes and secure sufficient capital resources for the often substantial period between technological conception and commercial sale.

Large and established companies such as Eli Lilly, Roche, Novo Nordisk, Pfizer, AstraZeneca, Amgen, Boehringer Ingelheim and Merck, among others, compete in the same general therapeutic areas as our product programs. These companies compete with us with their greater experience and resources to support their research and development efforts, conduct testing and clinical trials, obtain regulatory approvals to market products, manufacture such products on a broad scale and market approved products. These companies also compete with us by having significantly greater research and marketing capabilities than we do and may also have products that have been approved or are in late stages of development and have collaborative arrangements in our target markets with leading companies and research institutions. Established pharmaceutical companies may also invest heavily to accelerate discovery and development of novel compounds or to in-license novel compounds that could make the products that we develop obsolete. We also face competition from smaller companies who, like us, rely on investors to fund research and development and compete for co-development and licensing opportunities from large and established pharmaceutical companies.

We face competition for pemvidutide, our glucagon/GLP-1 dual agonist for the treatment of MASH from companies such as Madrigal Pharmaceuticals, Aligos and Viking Therapeutics, which are developing orally administered, thyroid hormone receptor (“THR”) β-selective agonists; Novo Nordisk, Roche, and GSK, which are developing fibroblast growth factor 21 (“FGF-21”) analogs; Novo Nordisk, which is developing a GLP-1 agonist; Merck/Hanmi Pharmaceutical and Boehringer Ingelheim, which are developing GLP-1/glucagon dual agonists; Eli Lilly, which is developing a glucose-dependent insulinotropic polypeptide receptor (“GIP”)/GLP-1 dual agonist and a GLP-1 GIP/glucagon triple agonist; Roche which is developing a GLP-1/GIP dual agonist; AstraZeneca developing a GLP-1/glucagon and amylin combination; Inventiva, which is developing a pan-peroxisome proliferator-activated receptor (“PPAR”) agonist; Sagimet which is developing a fatty acid synthetase inhibitor, Apollo Therapeutics Group Limited/HEC Pharma which is developing a GLP-1/FGF-21 dual agonist; and Pfizer, Roche, Gilead, AstraZeneca, and Eli Lilly, which are developing

11

Table of Contents

small molecule GLP-1 agonists. In addition, many other small companies are developing other new technologies directed towards MASH.

Similarly, we face competition for pemvidutide in the AUD and ALD markets. In ALD, GSK is developing GSK4532990, an RNAi targeting HSD17B13; Novo Nordisk is developing NNC0194-0499 (FGF-21), cagrilintide (long acting amylin analogue) and semaglutide (GLP-1). In AUD, Alkermes’ vivitrol is an approved product in this market; generic products such as naltrexone, acamprosate and disulfiram are also available; and Eli Lilly is developing mazdutide, a GLP-1/Glucagon dual agonist and brenipatide, a GLP-1/GIP dual agonist. We similarly face competition from smaller entrants in AUD; Adial is developing a serotonin-3 receptor antagonist targeting AG+ genotype AD-04, Imbrium is developing sunobinop, a NOP agonist, and Solvonis is developing SVN-001 for AUD in European markets.

Intellectual Property

We generally seek patent protection for our technology and product candidates in the United States and abroad. The patent coverage available to biotechnology companies is generally uncertain because it involves complex legal and factual considerations. Our success will depend, in part, on whether we can:

We have relied upon certain proprietary trade secrets, know-how and continuing technological advances to develop a competitive position. In efforts to maintain confidentiality and ownership of trade secrets, proprietary information and developments, all of our employees are required to execute agreements regarding confidentiality and assign to us all rights to any inventions and processes they develop while they are employed by us. We have and may in the future use license agreements to access external products and technologies and may in the future use license agreements to convey our own intellectual property to others. We will be able to protect our proprietary rights from unauthorized use by third parties only to the extent that our proprietary rights are covered by valid and enforceable patents or are effectively maintained as trade secrets.

Patent Rights Related to EuPort Technology

EuPort Technology — In-Licensed from Mederis Diabetes, LLC

Pursuant to a license agreement between the Company and Mederis Diabetes, LLC (“Mederis”) (the “Mederis IP License Agreement”), we are the exclusive licensee of patent rights owned by Mederis to develop and commercialize surfactant functionalized (“EuPort domain”) incretin-based peptide therapeutics, including (GLP-1-glucagon)/oxyntomodulin, and variants thereof, including pemvidutide, for any indication, and Mederis has certain patent rights granted back to it for the use of the EuPort technology outside of the Company’s exclusive field of incretin-based peptide therapeutics. The EuPort domain comprises a hydrophobic domain (e.g., substituted or unsubstituted alkyl chain) and a hydrophilic group (e.g., saccharide) conjugated to a non-terminal amino acid of the peptide. Patents under Mederis IP License Agreement have been granted in the United States, Japan and Korea, and applications are pending in the United States, Japan as well as other commercially relevant jurisdictions. The claims are directed to peptides (at least four amino acids in length), including peptides that bind receptors for glucagon and/or GLP-1, conjugated to an alkyl saccharide surfactant, including an alkyl glycoside surfactant. The patents and, if issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than May 2032, not giving effect to any potential extensions and assuming payment of all associated fees. Patents subject to the Mederis IP License Agreement have also been granted in the United States, Canada, Europe, Korea, Australia, Israel and Japan, and applications are pending in the United States, Europe, Japan, China and other commercially relevant jurisdictions, wherein the claims are directed to specific GLP-1 and/or glucagon peptides conjugated to the EuPort domain. The patents and, if issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than May 2035.

12

Table of Contents

Patent Rights Related to our Product Candidates

Pemvidutide, Dual GLP-1/Glucagon Dual Agonist for MASH, AUD and ALD

We are the exclusive licensee of patent rights owned by Mederis to develop and commercialize surfactant functionalized (GLP-1-glucagon)/oxyntomodulin-based peptide therapeutics, and variants thereof, including pemvidutide, for any use including the treatment of metabolic syndrome, insulin resistance, diabetes and cardiovascular disease. Patents under the Mederis IP License Agreement have been granted in the United States, Europe, Japan, Australia and Mexico with pending applications in the United States, Europe, Japan and Korea, as well as other commercially relevant jurisdictions. The claims are directed to GLP-1/glucagon dual agonist peptides conjugated to a surfactant and their use to treat metabolic syndrome and other related diseases. The patents and, if issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than May 2032 and extending to May 2035, with additional patents and patent applications which expire no earlier than 2041 should they be granted, not giving effect to any potential extensions and assuming payment of all associated fees. Use of pemvidutide for treating MASH or MASLD (referred to as NASH or NAFLD in the patent and patent applications) is further covered by, and subject to the Mederis IP License Agreement, with granted patents in the United States, Europe, Japan and Korea and pending applications in the United States, Europe, Japan and other commercially relevant jurisdictions. The patents and, if issued, the patent(s) resulting from the pending patent applications, are expected to have an expiration date of no earlier than January 2039, not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods with improved tolerability, dosing, dosing formulations and therapeutic regimens is further covered in pending applications in the United States, Europe, Japan and Korea, as well as other commercially relevant jurisdictions, which are owned by us and not subject to the Mederis IP License Agreement. The claims are directed to liquid formulations and the use of pemvidutide in a therapeutic dosing regimen with improved tolerability. If issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than February 2041 not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods for inducing weight loss is further covered in a granted patent in the United States and pending applications in the United States, Europe, Japan and Korea, as well as other commercially relevant jurisdictions owned by us and not subject to the Mederis IP License Agreement. The claims are directed to the use of pemvidutide for reducing body weight and in a therapeutic dosing regimen for chronic weight management. If issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than December 2041, not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods for reducing body weight in a human with fatty liver disease is further covered in pending patent applications in the United States, Europe, Japan and Korea, as well as other commercially relevant jurisdictions, which are owned by us and not subject to the Mederis IP License Agreement. The claims are directed to the use of pemvidutide in methods for reducing body weight in a human with MASH or MASLD (referred to as NASH or NAFLD in the patent and patent applications), with or without also having type II diabetes. If issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than September 2043, not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods for reducing the risk of cardiovascular (CV) disease is further covered in pending patent applications in the United States Europe, Japan and Korea, as well as other commercially relevant jurisdictions, which are owned by us and not subject to the Mederis IP License Agreement. The claims are directed to the use of pemvidutide in methods for reducing the risk of cardiovascular (CV) disease in a human with or without also having Type 2 diabetes. If issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than November 2043, not giving effect to any potential extensions and assuming payment of all associated fees.

A liquid formulation of pemvidutide for systemic administration and treatment of relevant indications is covered in patent applications owned by us and pending in the United States, Brazil, Canada, China, the European Patent Office, Israel, India, Japan, Korea, and Mexico. These patent applications are not subject to the Mederis IP License Agreement. If issued, the patent(s) resulting from the pending application(s) have expiration date(s) no earlier than November 2043, not giving effect to any potential extensions and assuming payment of all associated fees.

13

Table of Contents

Use of pemvidutide in methods for reducing pathological serum lipids is further covered in pending patents in the United States and corresponding international (PCT) patent applications, owned by us and not subject to the Mederis IP License Agreement, and from which we expect to file National Phase patent applications in commercially relevant jurisdictions. The claims are directed to the use of pemvidutide in methods for reducing/treating high cholesterol, LDL, triglycerides and/or blood pressure. If issued, the patent(s) resulting from the pending application(s) are expected to have expiration date(s) of no earlier than March 2045, not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods for treating AUD is further covered in a pending provisional patent application in the United States, owned by us and not subject to the Mederis IP License Agreement, and from which we expect to file a non-provisional application in the United States and a corresponding international (PCT) patent application. The claims are directed to the use of pemvidutide in methods for treating/reducing and/or maintaining reduced alcohol consumption. If issued, the patent(s) resulting from the pending application(s) have expiration date(s) of no earlier than March 2047, not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods for treating ALD is further covered in a pending provisional patent application in the United States, owned by us and not subject to the Mederis IP License Agreement, and from which we expect to file a non-provisional application in the United States and a corresponding international (PCT) patent application. The claims are directed to the use of pemvidutide in methods for treatment of ALD and methods of reducing liver fibrosis. If issued, the patent(s) resulting from the pending application(s) have expiration date(s) of no earlier than March 2047, not giving effect to any potential extensions and assuming payment of all associated fees.

Use of pemvidutide in methods for treating MASH in a human with noncirrhotic liver fibrosis is further covered in a pending provisional patent application in the United States, owned by us and not subject to the Mederis IP License Agreement, and from which we expect to file a non-provisional application in the United States and a corresponding international (PCT) patent application. The claims are directed to the use of pemvidutide in achieving MASH resolution within at least 24 weeks. If issued, the patent(s) resulting from the pending application(s) have an expiration date of no earlier than June 2047, not giving effect to any potential extensions and assuming payment of all associated fees.

The Company, via its wholly-owned subsidiary Spitfire Pharma, LLC, entered into a Collaboration and License Agreement with Adocia S.A. on December 24, 2024 under which the Company has exclusive rights to intellectual property pertaining to oral administration of pemvidutide, with patent applications pending, which if issued, would have an expiration date of no later than June 2043, and a US patent issuing in February 2026 that will have an expiration date no later than December 2044.

United States Government Regulation

The FDA regulates drugs and biological products under the Federal Food, Drug, and Cosmetic Act (“FD&C Act”), the Public Health Service Act (“PHS Act”), the regulations under Titles 21 and 42 of the Code of Federal Regulations (21 CFR and 42 CFR), as well as other federal, state and local statutes and regulations. The FD&C Act and the PHS Act and their corresponding regulations govern, among other things, the testing, research, manufacturing, approval, safety, efficacy, labeling, packaging, storage, record keeping, distribution, import, export, reporting, sale, advertising and other promotional practices involving drugs and biological products. An IND application must be in effect before clinical testing of drugs and biological products can begin. FDA approval must be obtained before drugs and biological products can be marketed. 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, and each process may take several years to complete, although certain expedited programs potentially applicable to our product candidates, such as FDA fast track designation for certain new drugs with the potential to address unmet medical needs for certain serious or life-threatening conditions, may potentially expedite development and/or approval processes. Certain federal incentive programs are also potentially applicable to our product candidates, such as for “orphan drugs” that treat rare conditions. Data obtained from clinical activities is not always conclusive and may be susceptible to varying interpretations, which could delay, limit or prevent regulatory approval. The FDA may not grant approval on a timely basis, or at all, and we may encounter difficulties or unanticipated costs in our efforts to secure necessary governmental approvals, which could delay or preclude us from marketing our product candidates. In addition, the FDA may limit the indications for use or place other conditions on any approvals that could restrict the commercial application

14

Table of Contents

of the products. After approval, some types of changes to the approved product, such as adding new indications, manufacturing changes and additional labeling claims, are subject to further testing requirements and FDA review and approval. In addition, our failure, or the failure of our third-party manufacturers, to comply with applicable regulations could result in sanctions being imposed on us, including clinical holds, fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocation, seizures or recalls of product candidates or products, operating restrictions and criminal prosecutions, any of which could adversely affect our ability to commercialize our product candidates.

Drug and Biological Products Development Process

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

Before testing any drug or biological product candidate in humans, the product candidate enters the preclinical study stage. Preclinical studies include laboratory evaluations of product chemistry, toxicity and formulation, as well as animal studies to assess the potential safety and activity of the product candidate. The conduct of certain preclinical studies must comply with federal regulations and requirements including GLP and the Animal Welfare Act.

The clinical trial sponsor must submit the results of the preclinical studies, together with manufacturing information, analytical data, any available clinical data or literature and a proposed clinical trial protocol, to the FDA as part of the IND. Some preclinical studies may continue even after the IND is submitted. The FDA requires a 30-day waiting period after the filing of each IND before clinical trials may begin. The FDA may also place the clinical trial on a clinical hold within that 30-day time period. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. Even after the IND has gone into effect and clinical testing has begun, the FDA

15

Table of Contents

may impose a partial or complete clinical hold on clinical trials due to safety concerns or non-compliance. A partial clinical hold can limit a trial, for example, to certain doses or for a certain length of time or to a certain number of subjects. A complete clinical hold order issued by the FDA would delay a proposed clinical study or suspend an ongoing study until all outstanding concerns have been adequately addressed and the FDA has notified the company that clinical investigations may proceed or resume. Accordingly, we cannot be sure that submission of an IND will result in the FDA allowing clinical trials to begin, or that, once the trials have begun, issues will not arise that suspend or terminate such studies.

Clinical trials involve the administration of the product candidate to healthy volunteers or patients under the supervision of qualified investigators. Clinical trials are conducted under protocols detailing, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria, and the parameters to be used to monitor subject safety, including stopping rules that assure a clinical trial will be stopped if certain AEs should occur. Each protocol and any amendments to the protocol must be submitted to the FDA as part of the IND during applicable phases of development. Clinical trials must be conducted and monitored in accordance with the FDA’s regulations and GCP requirements, which establish standards for conducting, recording data from, and reporting the results of clinical trials, with the goals of assuring that the data and results are credible and accurate and that study participants’ rights, safety, and well-being are protected. GCP requirements include the requirement that all research subjects provide informed consent. Further, each clinical trial must be reviewed and approved by an IRB at or servicing each institution at which the clinical trial will be conducted. An IRB is charged with protecting the welfare and rights of trial participants and considers such items as whether the risks to individuals participating in the clinical trials, not only from the investigational product itself but also from any required procedures or study visits to be conducted during the trial, are minimized and are reasonable in relation to anticipated benefits. The IRB also approves the form and content of the informed consent that must be signed by each clinical trial subject or his or her legal representative and must monitor the clinical trial until completed.

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

Post-approval clinical trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval. These clinical trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication, particularly for long-term safety follow-up.

During all phases of clinical development, regulatory agencies require extensive monitoring and auditing of all clinical activities, clinical data and clinical trial investigators. Annual progress reports detailing the results of the clinical trials must be submitted to the FDA. Written IND safety reports must be promptly submitted to the FDA and the investigators for serious and unexpected AEs, any findings from other studies, tests in laboratory animals or in vitro testing and other sources that suggest a significant risk for human subjects, or any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator brochure. The sponsor must submit an IND safety report within 15 calendar days after the sponsor determines that the information qualifies for reporting. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within 7

16

Table of Contents

calendar days after the sponsor’s initial receipt of the information. Phase 1, Phase 2 and Phase 3 clinical trials may not be completed successfully within any specified period, if at all. 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 or biological product has been associated with unexpected serious harm to patients.

In limited circumstances, FDA also permits the administration of investigational small molecule drug or biological products to patients under its expanded access regulatory authorities. Under the FDA’s expanded access authority, patients who are not able to participate in a clinical trial may be eligible for accessing investigational products, including through individual compassionate or emergency use in concert with their requesting physician. Additionally, a manufacturer of an investigational drug for a serious disease or condition is required to make available, such as by posting on its website, its policy on evaluating and responding to requests for individual patient access to such investigational drug. This requirement applies on the earlier of the first initiation of a Phase 2 or Phase 3 trial of the investigational drug or, as applicable, 15 days after the drug receives a designation as a breakthrough therapy, fast track product, or regenerative medicine advanced therapy.

Concurrent with clinical trials, companies usually complete additional animal studies, develop additional information about the physical characteristics of the drug or biological product candidate and finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. To help reduce the risk of the introduction of adventitious agents with use of biological products, the PHS Act emphasizes the importance of manufacturing controls for products whose attributes cannot be precisely defined. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the sponsor must develop methods for testing the identity, strength, quality, potency and purity of the final product. Additionally, 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.

Certain FDA programs are available to facilitate and expedite the development and review of new drugs intended to address unmet needs in the treatment of serious or life-threatening conditions. These expedited programs include fast track designation, breakthrough therapy designation, priority review and accelerated approval. Each of these programs has its own features and qualifying criteria.

The Fast Track designation program is intended to expedite or facilitate the process for reviewing new drug candidates that are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast Track designation applies to the combination of the drug candidate and the specific indication for which it is being studied. The sponsor of a Fast Track designated product has opportunities for more frequent interactions with the applicable FDA review team during product development and, once an NDA is submitted, the drug candidate may be eligible for priority review. A Fast Track designated drug candidate may also be eligible for rolling review, where the FDA may consider for review sections of the NDA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the NDA, the FDA agrees to accept sections of the NDA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the NDA.

A drug candidate intended to treat a serious or life-threatening disease or condition may also be eligible for Breakthrough Therapy designation to expedite its development and review. A drug candidate can receive Breakthrough Therapy designation if preliminary clinical evidence indicates that the drug candidate, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the Fast Track designation program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the drug candidate, including involvement of senior managers.

In addition, products tested for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may be eligible for accelerated approval and may be approved on the basis of adequate and well-controlled clinical trials establishing that the drug product has an effect on a

17

Table of Contents

surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, or IMM, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity or prevalence of the disease and the availability or lack of alternative treatments. As a condition of approval, the FDA may require a sponsor of a drug or biologic receiving accelerated approval to perform post-marketing studies to verify and describe the predicted effect on IMM or other clinical endpoint, and the drug or biologic may be subject to accelerated withdrawal procedures. Further, under the Food and Drug Omnibus Reform Act of 2022 (“FDORA”), the FDA must specify the conditions for any post-approval trials by the date of accelerated approval and the agency has flexibility in setting forth such conditions, which may include enrollment targets, clinical trial protocol and milestones – including the target date of trial completion. The FDA may also require, as appropriate, that certain confirmatory trials be underway prior to accelerated approval or within a specified time from the date of approval. Accelerated approval sponsors must submit progress reports every six months on required post-approval trials. FDORA also gives the FDA increased authority to withdraw approval of a drug or biologic granted accelerated approval on an expedited basis if the sponsor fails to conduct such studies in a timely manner, send the necessary updates to the FDA, or if such post-approval studies fail to verify the drug’s predicted clinical benefit. Under FDORA, the FDA is empowered to take action, such as issuing fines, against companies that fail to conduct with due diligence any post-approval confirmatory study or submit timely reports to the agency on their progress.

A sponsor must submit a request for fast track designation, breakthrough therapy designation, or priority review, which may or may not be granted by the FDA. For fast track and breakthrough therapy designations, FDA may later decide the product no longer meets the conditions for designation and may rescind the designation. For accelerated approval, a sponsor generally discusses the possibility of accelerated approval with the FDA during development, and the FDA may or may not agree that accelerated approval is an appropriate pathway for a particular drug. Some of these expedited programs could potentially apply to our product candidates, although this cannot be assured, and we do not currently have any products with expedited program designations. Even if a product candidate obtains accelerated approval based on surrogate clinical endpoints, the sponsor of such product candidate is still required to complete a more extensive outcomes trial to obtain full regulatory approval. Such outcomes trial may not replicate the early positive results that supported the accelerated approval in which case the FDA will remove the accelerated approval.

The sponsor of a clinical trial or the sponsor’s designated responsible party may be required to register certain information about the trial and disclose certain results on government websites, such as ClinicalTrials.gov. Information related to the product, patient population, phase of investigation, trial sites and investigators, and other aspects of the clinical trial is made public as part of the registration. Sponsors are also obligated to disclose the results of their clinical trials after completion. Disclosure of the results of these trials can be delayed until the new product or new indication being studied has been approved. Competitors and patients may use this publicly available information to gain knowledge regarding the progress of development programs. Failure to timely register a covered clinical study or to submit study results as provided for in the law could lead to consequences such as public notifications of noncompliance and civil monetary penalties.

Review and Approval Processes

After the completion of clinical trials of a drug or biological product candidate, the FDA’s approval of an NDA or BLA must be obtained before commercial marketing of the product may begin. The NDA or BLA must include results of product development, laboratory and animal studies, human studies, information on the manufacture and composition of the product, proposed labeling and other relevant information. In addition, under the Pediatric Research Equity Act, as amended, an NDA or BLA or supplement to an NDA or BLA generally must contain data to assess the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may grant deferrals for submission of data or full or partial waivers depending on the designated pathway for submission. The testing and approval processes require substantial time and effort and there can be no assurance that the FDA will accept the NDA or BLA for filing and, even if filed, that any approval will be granted on a timely basis, if at all.

Under the Prescription Drug User Fee Act (“PDUFA”), as amended, each NDA or BLA must be accompanied by a significant application fee. PDUFA also imposes an annual prescription drug product program fee for biologics. Fee waivers or reductions are available in certain circumstances, including a waiver of the application fee for the first application filed by a small business.

18

Table of Contents

Following submission of the application, the FDA reviews the NDA or BLA to determine if it is substantially complete before the agency accepts it for filing. The FDA may refuse to file any NDA or BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the NDA or BLA must be resubmitted with the additional information. The resubmitted application also is subject to review before the FDA accepts it for filing. Once the submission is accepted for filing, the FDA begins an in-depth substantive review of the NDA or BLA. FDA performance goals generally provide for action on an NDA or BLA within 10 months of the 60-day filing date, which would be within 12 months of its submission. That deadline can be extended under certain circumstances, including by the FDA’s requests for additional information. The targeted action date can also be shortened to 6 months of the 60-day filing date, or 8 months after submission, for products that are granted priority review designation because they are intended to treat serious or life-threatening conditions and demonstrate the potential to address unmet medical needs. The FDA reviews the NDA or BLA to determine, among other things, whether the proposed product is safe and effective for its intended use, and whether the product is being manufactured in accordance with cGMP to assure the product’s identity, safety, quality, potency and purity. The FDA may refer applications for drugs or biological products that are novel or that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and 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.

During the NDA or BLA review process, the FDA also will determine whether a Risk Evaluation and Mitigation Strategy (“REMS”) is necessary to assure the safe use of the drug or biological product. If the FDA concludes a REMS is needed, the sponsor of the NDA or BLA must submit a proposed REMS; the FDA will not approve the NDA or BLA without a REMS, if required. A REMS could include medication guides, physician communication plans or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. Any of these limitations on approval or marketing could restrict the commercial promotion, distribution, prescription or dispensing of products.

Before approving an NDA or BLA, the FDA will inspect the facilities at which the product is manufactured. The FDA will not approve the NDA or BLA unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving an NDA or BLA, the FDA will typically inspect one or more clinical sites to assure that the clinical trials were conducted in compliance with IND study requirements and GCP requirements. To assure cGMP and GCP compliance, an applicant must incur significant expenditure of time, money and effort in the areas of training, record keeping, production and quality control.

Notwithstanding the submission of relevant data and information, the FDA may ultimately decide that the NDA or BLA does not satisfy its regulatory criteria for approval. Data obtained from clinical trials are not always conclusive and the FDA may interpret data differently than how we interpret the same data. If the agency decides not to approve the NDA or BLA in its present form, the FDA will issue a complete response letter that usually describes all of the specific deficiencies in the NDA or BLA identified by the FDA. The deficiencies identified may be minor, for example, requiring labeling changes; or major, for example, requiring additional clinical trials. Additionally, the complete response letter may include recommended actions that the applicant may take for the FDA to reconsider the application. If a complete response letter is issued, the applicant may either resubmit the NDA or BLA, addressing all of the deficiencies identified in the complete response letter, or withdraw the application.

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. Further, the FDA may require that certain contraindications, warnings or precautions be included in the product labeling. The FDA may impose restrictions and conditions on product distribution, prescribing, or dispensing in the form of a REMS, or otherwise limit the scope of any approval. In addition, the FDA may require post-marketing clinical trials, sometimes referred to as Phase 4 clinical trials, designed to further assess a product’s safety and effectiveness, and testing and surveillance programs to monitor the safety of approved products that have been commercialized. Post-approval modifications to a drug product, such as changes in indications, labeling or manufacturing processes or facilities, may require development and submission of additional information or data in a new or supplemental NDA or BLA, which would also require prior FDA approval.

19

Table of Contents

Post-Approval Requirements

After regulatory approval of a product is obtained, products are subject to extensive continuing regulation and post-approval requirements. For example, as a condition of approval of an NDA or BLA, the FDA may require post-marketing testing and surveillance to monitor the product’s safety or efficacy. In addition, holders of an approved NDA or BLA are required to keep extensive records, submit annual reports, report certain adverse reactions and production problems to the FDA, provide updated safety and efficacy information, and comply with requirements concerning advertising and promotional labeling for their products.

In addition, quality control and manufacturing procedures must continue to conform to cGMP regulations and practices, as well as the manufacturing conditions of approval set forth in the NDA or BLA. Drug manufacturers and their subcontractors and those supplying products, ingredients, and components are required to register their establishments with the FDA and certain state agencies, and the FDA periodically inspects manufacturing facilities to assess compliance with cGMP, which imposes certain procedural, substantive and recordkeeping requirements. Manufacturers and other parties involved in the drug supply chain for prescription drug products also must comply with product tracking and tracing requirements and notify the FDA of counterfeit, diverted, stolen and intentionally adulterated products or products that are otherwise unfit for distribution in the United States. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance. If, after receiving approval, a company makes a material change in manufacturing equipment, location, or process (all of which are, to some degree, incorporated in the NDA or BLA), additional regulatory review and approval may be required.

Future FDA inspections may identify cGMP compliance issues at manufacturer facilities or at the facilities of third-party suppliers that may disrupt production or distribution or require substantial resources to correct and prevent recurrence of any deficiencies, and could result in fines or penalties by regulatory authorities. In addition, discovery of problems with a product or the failure to comply with applicable requirements may result in restrictions on a product, manufacturer or holder of an approved NDA or BLA, including withdrawal or recall of the product from the market or other voluntary, FDA-initiated or judicial action, including warning letters, fines, injunctions, civil penalties, license revocations, seizure, total or partial suspension of production or criminal penalties, any of which could delay or prohibit further marketing. Newly discovered or developed safety or efficacy data may require changes to a product’s approved labeling, including the addition of new warnings and contraindications.

From time to time, legislation is drafted, introduced, passed in Congress and signed into law that could significantly change the statutory provisions governing the approval, manufacturing, and marketing of products regulated by the FDA. In addition to new legislation, FDA regulations, guidance, and policies can be revised or reinterpreted by the agency in ways that may significantly affect the manner in which pharmaceutical products are regulated and marketed.

Certain U.S. Regulatory Incentives and Other Programs

Marketing Exclusivity and Patent Term Restoration

The Drug Price Competition and Patent Term Restoration Act of 1984, also referred to as the Hatch-Waxman Amendments, established certain periods of marketing exclusivity for new drugs approved by the FDA, including a five-year period of non-patent marketing exclusivity within the United States to the first applicant to gain approval of an NDA for a new chemical entity. A drug is a new chemical entity 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 (“ANDA”) or a 505(b)(2) NDA submitted by another applicant for such drug where the applicant does not own or have a right of reference to 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. The Hatch-Waxman Amendment also established a three-year period of marketing exclusivity for an NDA, 505(b)(2) NDA, or supplement to an 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 (e.g., new indications, dosages or strengths of an approved drug). This three-year exclusivity covers only the conditions of use associated with the new clinical investigations and does not prohibit the FDA from approving ANDAs for drugs containing the active ingredient for other conditions of use.

20

Table of Contents

Additionally, products approved under an NDA or BLA may qualify for the restoration of a portion of the patent term lost during product development and FDA review of the application, if approval of the application is the first permitted commercial marketing of a drug containing the active ingredient. The patent term restoration period is generally one-half the time between the effective date of the IND or the date of patent grant (whichever is later) and the date of submission of the NDA or BLA, plus the time between the date of submission of the NDA or BLA and the date of FDA approval of the product. The maximum period of restoration is five years, and the patent cannot be extended to more than 14 years from the date of FDA approval of the product. Only one patent claiming each approved product is eligible for restoration and the patent holder must apply for restoration within 60 days of approval. The USPTO, in consultation with the FDA, reviews and approves the application for patent term restoration.

Pediatric Exclusivity

Drugs and biological products, such as our product candidates, may be eligible for pediatric exclusivity, an incentive intended to encourage medical product research for children. Pediatric exclusivity, if granted, may add six months to certain patents or regulatory exclusivity periods applicable to an approved drug and six months to regulatory exclusivity periods applicable to an approved biological product. This additional six months of exclusivity may be granted based on the completion of one or more pediatric trials in response to a Written Request from the FDA. It is possible, but not assured, that certain of our current or future product candidates may be targeted to pediatric populations.

Orphan Drug Designation

The FDA may grant orphan drug designation to drugs intended to treat a “rare disease or condition” that affects fewer than 200,000 individuals in the United States, or that affects more than 200,000 individuals in the United States and for which there is no reasonable expectation that the cost of developing and making available in the United States a drug for such a disease or condition will be recovered from sales in the United States for that drug. Orphan drug designation must be requested before submitting an application for marketing approval. Orphan drug designation can provide opportunities for grant funding toward clinical trial costs, tax advantages and FDA user fee exemptions. In addition, if a product that has an orphan drug designation subsequently receives FDA approval for the indication for which it has such designation, the product may be entitled to orphan drug exclusivity, which means the FDA would not approve any other application to market the same drug for the same indication for a period of seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan exclusivity. It is possible, but not assured, that certain of our current or future product candidates may target rare diseases or conditions.

U.S. Regulations Affecting Health Care Companies

Pharmaceutical manufacturers with products that are reimbursed by U.S. federally funded health care programs such as Medicare and Medicaid are subject to so-called fraud and abuse laws including false claims and anti-kickback laws.

The federal Anti-Kickback Law prohibits anyone from, among other things, knowingly and willingly, directly or indirectly, soliciting, receiving, offering, or paying any remuneration with the intent of (or in return for) generating referrals of individuals or purchases, leases, orders, or arranging for the purchase, lease, or order of any healthcare item or service reimbursable by federal health care programs like Medicare and Medicaid. Courts have interpreted this law very broadly, including by holding that a violation has occurred if one purpose of the remuneration is to generate referrals even if there are other lawful purposes. Moreover, liability under the Anti-Kickback Law may be established without proving actual knowledge of the law or specific intent to violate. There are statutory exceptions and regulatory safe harbors that protect certain arrangements from prosecution or administrative sanctions, but the exceptions and safe harbors are drawn narrowly. The fact that an arrangement does not fall within a safe harbor does not necessarily render the conduct illegal under the Anti-Kickback Law, but the arrangement may be subject to scrutiny based on the facts and circumstances. Practices that involve remuneration to those who prescribe, purchase, or recommend pharmaceutical products, including certain discounts, or engaging such individuals as consultants, advisors and speakers, may be subject to scrutiny if they do not fit squarely within an exception or safe harbor. Moreover, there are no safe harbors for many common practices, such as educational and research grants, charitable donations, product support and patient assistance programs. Violations of the Anti-Kickback Law may be punished by civil and criminal penalties, damages, fines, or exclusion from participation in

21

Table of Contents

federal health care programs like Medicare and Medicaid. Many states have enacted similar laws, some of which apply regardless of payer.

The Federal civil False Claims Act (“FCA”) prohibits any person from, among other things, knowingly presenting or causing to be presented a false or fraudulent claim for payment of government funds, or 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 knowingly concealing or knowingly and improperly avoiding, decreasing, or concealing an obligation to pay or transmit money or property to the government. The FCA is commonly enforced against those who submit allegedly false Medicare or Medicaid claims, as well as those who induce or assist others to submit a false claim. “False claims” can result not only from non-compliance with the express requirements of applicable governmental reimbursement programs, such as Medicaid or Medicare, but also from non-compliance with other laws, such as the Anti-Kickback Law or laws that require quality care in service delivery. Actions under the FCA may be brought by the government or by whistleblowers referred to as “relators,” who may initiate an action in the name of the government and the individual and may share in any monetary recovery. Violations of the FCA can result in treble damages, mandatory per claim penalties, and exclusion from participation in federal health care programs. Most states have adopted similar state false claims laws, some of which are broader than the FCA, and these state laws have their own penalties which may be in addition to FCA penalties.

The Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, significantly strengthened the FCA and federal Anti-Kickback Law provisions, which could lead to the possibility of increased whistleblower or relator suits, and among other things, made clear that a federal Anti-Kickback Law violation can be a basis for federal FCA liability. The bringing of any FCA or other enforcement investigation or action, even if unsuccessful, could require us to devote resources to investigate and defend the action, as well as result in reputational harm. Failure to comply with fraud and abuse laws could result in significant civil and criminal penalties and costs, including the loss of licenses and the ability to participate in federal and state health care programs, and could have a material adverse effect on our business. In addition, many of these laws are vague, subject to modification, and are subject to evolving interpretation by prosecutorial and regulatory authorities, increasing the risk of noncompliance. We cannot predict whether changes in applicable law, or interpretation of laws, or changes in our services or marketing practices in response to changes in applicable law or interpretation of laws, could have a material adverse effect on our business.

In addition to the above, several other laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, structuring and commission(s), and other business arrangements generally. Activities subject to these laws also involve the improper use of information obtained in the course of patient recruitment for clinical trials. Some state laws restrict whether and when pharmaceutical companies may provide meals to health care professionals or engage in other marketing-related activities; some states require certain compliance program elements and disclosures; and certain states and cities require identification or licensing of sales representatives.

For example, the federal Health Insurance Portability and Accountability Act of 1996, and its implementing regulations (collectively, “HIPAA”), prohibits knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program or obtain, by means of false or fraudulent pretenses, representations, or promises, any of the money or property owned by, or under the custody or control of, any healthcare benefit program, regardless of the payer (e.g., public or private) and knowingly and willfully falsifying, concealing or covering up by any trick or device a material fact or making any materially false statements in connection with the delivery of, or payment for, healthcare benefits, items or services relating to healthcare matters. Similar to the Anti-Kickback Law, a person or entity can be found guilty of violating the HIPAA fraud statute without actual knowledge of the statute or specific intent to violate it. Violations of HIPAA fraud provisions may result in criminal, civil and administrative penalties, fines and damages, including exclusion from participation in federal healthcare programs.

Privacy Laws

In the U.S., we may be subject to data privacy and security laws and regulations by both the federal government and the states in which we conduct our business. The legislative and regulatory landscape for privacy and data protection continues to evolve, and there has been an increasing focus on privacy and data protection issues which may affect our business. Numerous federal and state laws and regulations now govern the collection, use, disclosure, and protection of personal information, including health-related information that we may collect in connection with clinical trials.

22

Table of Contents

At the state level, the California Consumer Privacy Act (“CCPA”), for example, grants individual privacy rights for California consumers (as defined in the law) and places increased privacy and security obligations on entities handling personal information of consumers and households. The CCPA requires covered businesses to provide certain disclosures about its data collection, use and sharing practices, and provide specific notices and opt-out rights to consumers with respect to certain sales and transfers of their personal information. As of January 2026, more than a dozen other U.S. states have enacted similarly comprehensive privacy legislation. Several additional states passed laws specific to consumer health data, such as Washington’s My Health My Data Act, and other state laws, such as the Texas Genomic Privacy Act, focus specifically on genetic information.

Additionally, HIPAA imposes requirements relating to the privacy, security and transmission of individually identifiable health information. While many consumer privacy laws contain exceptions for certain activities involving the processing of health information regulated under HIPAA, and for clinical trials conducted in accordance with federal regulations, this has become an increasingly complex regulatory landscape.

At the federal level, regulators and legislators are increasingly scrutinizing and restricting certain personal data transfers and transactions involving foreign countries. For example, the Department of Justice’s January 8, 2025, rule on “Preventing Access to U.S. Sensitive Personal Data and Government-Related Data by Countries of Concern or Covered Persons,” prohibits data brokerage transactions involving certain sensitive personal data categories, including health data, genetic data, and biospecimens, to countries of concern, including China.

Outside of the U.S., the legislative and regulatory landscape for privacy and data security is just as complex. The General Data Protection Regulation in the EU and the U.K. and data protection laws in the U.K, for example, impose potentially significant fines, and laws and regulations enacted in Asia and Latin America increase potential enforcement and litigation activity.

Any associated claims, inquiries, or investigations or other actions under these laws could lead to significant penalties or fines, monetary judgments or settlements including criminal and civil liability.

U.S. Health Care Reform Law

Our financial prospects could be affected by changes in health care spending and policy in the United States and abroad. We operate in a highly regulated industry and new laws, regulations, or judicial decisions, or new interpretations of existing laws, regulations, or decisions, related to, among other things, health care availability, or the method of delivery of or payment for health care products and services could negatively impact our business, operations and financial condition.

For example, in the United States there is significant interest in promoting health care reform, as evidenced by the enactment in the United States of the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the “Health Care Reform Law”). The Health Care Reform Law substantially changed the way health care is financed by both governmental and commercial payers and significantly impacts the pharmaceutical industry. The Health Care Reform Law contains provisions that may reduce the profitability of drug products, including, for example, by increasing the minimum rebates owed by manufacturers under the Medicaid Drug Rebate Program, extending the rebate program to individuals enrolled in Medicaid managed care plans, addressing a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected, and imposing certain annual fees based on pharmaceutical companies’ share of sales to federal health care programs.

The Health Care Reform Law established and provided significant funding for a new Patient-Centered Outcomes Research Institute to coordinate and fund comparative effectiveness research. While the stated intent of comparative effectiveness research is to develop information to guide providers to the most efficacious therapies, outcomes of comparative effectiveness research could influence the reimbursement or coverage for therapies that are determined to be less cost effective than others. Should any of our products be approved for sale, but then determined to be less cost effective than alternative therapies, the levels of reimbursement for these products, or the willingness to reimburse at all, could be impacted, which could materially impact our financial results.

23

Table of Contents

Certain provisions of the Health Care Reform Law have been subject to judicial challenges, as well as efforts to repeal, replace or otherwise modify them or to alter their interpretation or implementation. Additional legislative changes, regulatory changes and judicial challenges related to the Health Care Reform Law remain possible, but the nature and extent of such potential changes or challenges are uncertain at this time.

Another provision of the Health Care Reform Law, generally referred to as the Physician Payments Sunshine Act or Open Payments Program, requires manufacturers of drugs, devices, biologics, and medical supplies for which payment is available under Medicare, Medicaid, or the Children’s Health Insurance Program (with certain exceptions) to report annually to CMS information related to direct or indirect payments and other transfers of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), to certain non-physician providers such as physician assistants, nurse practitioners, clinical nurse specialists, certified nurse anesthetists and certified nurse-midwives, and to teaching hospitals, as well as ownership and investment interests held in the company by physicians and their immediate family members. Effective January 1, 2022, these reporting obligations have been extended to include transfers of value made. CMS publishes information from these reports on a publicly available website. Our compliance with these rules may also impose additional costs and may impact our relationships with physicians, teaching hospitals and the other non-physician health care providers.

In addition, other legislative changes have been proposed and adopted since the Health Care Reform Law was enacted. For example, the Budget Control Act of 2011 and subsequent legislation led to aggregate reductions in Medicare payments for all items and services, including prescription drugs and biologics, to service providers of, on average, 2% per fiscal year through 2031.

As another example, the Inflation Reduction Act of 2022 (“IRA”) includes several provisions that will impact our business to varying degrees, including provisions that create a $2,000 out-of-pocket cap for Medicare Part D beneficiaries, impose new mandatory discounts from manufacturers under Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D pricing for certain high-cost single-source drugs and biologics without generic competition, and require companies to pay rebates to Medicare for drug prices that increase faster than inflation. The IRA delays the rebate rule that would require pass through of pharmacy benefit manager rebates to beneficiaries. The effect of IRA on our business and the healthcare industry in general is not yet known.

Additional legislative changes, regulatory changes or guidance could be adopted, or executive orders or other actions undertaken, which may impact the marketing approvals and reimbursement for our product candidates. The One Big Beautiful Bill Act of 2025 (“OBBBA”), for example, imposed significant reductions in Medicaid funding, additional work requirements for Medicaid recipients, and more frequent reenrollment requirements. These changes are expected to place substantial pressure on state Medicaid budgets, reduce enrollment, and limit covered services, which could decrease utilization of, and reimbursement for, our products, if approved.

The costs of prescription pharmaceuticals have also been the subject of considerable discussion in the United States. To date, there have been several recent U.S. congressional inquiries, as well as proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, reduce the costs of drugs under Medicare and reform government program reimbursement methodologies for drug products. The Trump Administration has issued executive orders and supported proposed regulatory initiatives in 2025 that could have a significant impact on the prices that we, or any collaborators, may receive for any approved products.

On May 12, 2025, President Trump signed an executive order directing the Secretary of HHS to set and communicate most-favored-nation (“MFN”) price targets to manufacturers and propose a rulemaking plan to impose MFN pricing if “significant progress” is not made, and also directing the federal government to support regulatory paths to allow direct-to-patient sales for companies that meet these targets. The executive order further states that the Administration will take additional action (for example, examining whether marketing approvals should be modified or rescinded or considering individual drug importation waiver authorities) should manufacturers fail to offer American consumers the MFN lowest price. In July 2025, President Trump sent letters to certain pharmaceutical companies demanding that these companies extend MFN pricing to Medicaid and newly launched drugs as well as move to direct-to-consumer models priced at MFN pricing, and soliciting binding commitments by September 29, 2025. Since this time, multiple drug manufacturers have announced plans to, for certain of their drugs, lower prices to reflect similar pricing around the world,

24

Table of Contents

and to sell these reduced-price drugs on a direct-to-consumer purchasing platform developed by the federal government; however, it is not known what results will occur to the extent the recipients of these letters do not reduce their U.S. prices.

On December 19, 2025, CMS released two proposed rules that would incorporate MFN pricing principles into federal reimbursement for prescription drugs. The first proposal, the Global Benchmark for Efficient Drug Pricing Model (“GLOBE”) for Medicare Part B, would require manufacturers of specified single source drugs and sole source biologics to pay incremental rebates based on international benchmark prices, with participation triggered for products meeting CMS’s spending and eligibility criteria. The second proposal, the Guarding U.S. Medicare Against Rising Drug Costs (“GUARD”) model for Medicare Part D, would similarly mandate manufacturer rebates for qualifying sole source drugs where the Medicare net price exceeds an MFN benchmark derived from international reference pricing methodologies. As proposed, GLOBE would begin a five year performance period on October 1, 2026 and GUARD would begin its performance period in 2027. These proposals will likely be subject to legal challenges that could delay their implementation or modify their impact on manufacturer pricing and revenue. Additionally, in November 2025, CMS introduced the GENErating cost Reductions fOr U.S. Medicaid (“GENEROUS”) Model, a voluntary MFN framework for manufacturers participating in the Medicaid Drug Rebate Program. Although it is voluntary, the GENEROUS Model could also impact the drug pricing landscape for manufacturers.

Further, there has been increasing legislative, regulatory and enforcement interest in the United States with respect to drug pricing practices. There have been several Congressional inquiries and proposed and enacted federal and state legislation and regulatory initiatives designed to, among other things, bring more transparency to product pricing, evaluate the relationship between pricing and manufacturer patient programs, and reform government healthcare program reimbursement methodologies for drug products.

It is possible that the Health Care Reform Law, as currently enacted or may be amended or otherwise modified in the future, as well as other health care reform measures that may be adopted in the future, may result in additional reductions in Medicare payment and other health care financing, more rigorous coverage criteria, and new payment methodologies and in additional downward pressure on coverage and payment and the price that we receive for any approved product. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payers. We cannot predict the reform initiatives that may be adopted in the future or whether initiatives that have been adopted will be repealed or modified. These continuing health care reform initiatives may adversely affect:

Congress also could enact additional changes that affect our overall rebate liability and the information we report to the government as part of price reporting calculations. In addition, Congress could enact a drug price negotiation program under which the prices for certain high Medicare spend single source drugs would be capped by reference to the non-federal average manufacturer price. This or any other legislative change could impact the market conditions for our products. We further expect continued scrutiny on government price reporting and pricing more generally from Congress, agencies, and other bodies.

Coverage and Reimbursement

In the United States and markets in other countries, patients generally rely on third-party payers to reimburse all or part of the costs associated with their treatment. Adequate coverage and reimbursement from governmental healthcare programs, such as Medicare and Medicaid, and commercial payers is critical to new product acceptance. Our ability to successfully commercialize our product candidates will depend in part on the extent to which coverage and adequate

25

Table of Contents

reimbursement for these products and related treatments will be available from government health administration authorities, private health insurers and other organizations. Government authorities and third-party payers, such as private health insurers and health maintenance organizations, decide which medications they will pay for and establish reimbursement levels. The availability of coverage and extent of reimbursement by governmental and private payers is essential for most patients to be able to afford treatments such as gene therapy products. Sales of these or other product candidates that we may identify will depend substantially, both domestically and abroad, on the extent to which the costs of our product candidates will be paid by health maintenance, managed care, pharmacy benefit and similar healthcare management organizations, or reimbursed by government health administration authorities, private health coverage insurers and other third-party payers. If coverage and adequate reimbursement is not available, or is available only to limited levels, we may not be able to successfully commercialize our product candidates. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize a sufficient return on our investment.

There is also significant uncertainty related to the insurance coverage and reimbursement of newly approved products and coverage may be more limited than the purposes for which the medicine is approved by the FDA or comparable foreign regulatory authorities. In the United States, the principal decisions about reimbursement for new medicines may be made by CMS. CMS decides whether and to what extent certain new medicines will be covered and reimbursed under Medicare and private payers tend to follow CMS to a substantial degree.

Environmental Regulations

We are also subject to regulation under the Occupational Safety and Health Act, the Environmental Protection Act, the Toxic Substances Control Act, the Resource Conservation and Recovery Act and other present and potential federal, state or local regulations. These and other laws govern our use, handling and disposal of various biological and chemical substances used in, and waste generated by our operations. Our research and development involve the controlled use of hazardous materials, chemicals and viruses. Although we believe that our safety procedures for handling and disposing of such materials comply with the standards prescribed by state and federal regulations, the risk of accidental contamination or injury from these materials cannot be completely eliminated. In the event of such an accident, we could be held liable for any damages that result and any such liability could exceed our resources. Additionally, for formulations containing controlled substances, we are subject to Drug Enforcement Act regulations.

Pricing Regulations

There have been a number of federal and state legislative changes made over the last few years regarding the pricing of pharmaceutical and biological products, government control and other changes to the health care system of the United States. Concerns about drug pricing continue to be expressed by members of Congress and prior presidential administrations. It is uncertain how such legislative changes will be adopted or what actions federal, state or private payers for medical goods and services may take in response to such legislation. We cannot predict the effect such health care changes will have on our business, and no assurance can be given that any such reforms will not have a material adverse effect.

Non-U.S. Government Regulations

European Union Drug Development

Our products will also be subject to extensive regulatory requirements in the European Union (“EU”). As in the United States, medicinal products can only be marketed if a marketing authorization from the competent regulatory agencies has been obtained. See “European Marketing Authorization” below.

In the EU, the Clinical Trials Regulation 536/2014 has been applicable since January 31, 2022. The Clinical Trials Regulation repealed and replaced the Clinical Trials Directive, and introduced a complete overhaul of the existing regulation of clinical trials for medicinal products in the EU, including a new coordinated procedure for authorization of clinical trials that will be conducted in multiple EU Member States, and increased obligations on sponsors to publish clinical trial results. The Regulation is directly applicable in all EU Member States (and so does not require national implementing legislation in each EU Member State) and aims at simplifying and streamlining the approval of clinical

26

Table of Contents

studies in the EU. The main characteristics of the Regulation include: a streamlined application procedure via a single-entry point through the Clinical Trials Information System, or CTIS; a single set of documents to be prepared and submitted for the application as well as simplified reporting procedures for clinical trial sponsors; and a harmonized procedure for the assessment of applications for clinical trials, which is divided in two parts (Part I contains scientific and medicinal product documentation and Part II contains the national and patient-level documentation). Part I is assessed by a coordinated review by the competent authorities of all EU Member States in which an application for authorization of a clinical trial has been submitted (Member States concerned) of a draft report prepared by a Reference Member State. Part II is assessed separately by each Member State concerned. Strict deadlines have also been established for the assessment of clinical trial applications.

Similar to the FDA, the European Medicines Agency’s Committee for Medicinal Products for Human Use (“CHMP”) has adopted ICH S6 (R1) as a guideline governing preclinical testing of biologics. Sponsors usually must conduct pharmacodynamic (“PD”) studies, such as in vitro binding assays and in vivo studies that assess the product’s pharmacologic activity and define its mechanism of action. Biologics typically undergo single- and repeat-dose toxicity studies using relevant species. Safety pharmacology studies, which evaluate the product’s functional effects on major body systems and specific organs, and local tolerance testing can be done separately or subsumed in toxicity testing. Sponsors also usually conduct single- and multiple-dose pharmacokinetic (“PK”) and/or toxicokinetic studies to assess absorption, disposition, exposure and clearance (in particular, antibody-mediated clearance), and explore dose-response relationships. This information is used to predict margins of safety for human studies. Immunogenicity testing might include screening and mechanistic studies.

Good Clinical Practices and Other Considerations for Clinical Trials

Clinical trials of medical products (including biologics) must comply with GCP, as described in Directive 2005/28/EC on Good Clinical Practice and the ICH E6 (R3) guideline, which the CHMP has adopted. The Directive and guideline describe general governing principles for clinical trials. The rights, safety and well-being of trial subjects must prevail over the interests of science and society. Investigators must obtain freely given informed consent from every trial subject before each subject is enrolled. Clinical trial information must be handled, recorded and stored with respect for relevant confidentiality and privacy rules. Trials must comply with the ethical principles of the World Medical Association’s Declaration of Helsinki. Specific GCP guidelines apply to trials of advanced therapy medicinal products (i.e. gene therapy, somatic-cell therapy and tissue-engineered medicines). These guidelines regulate issues such as the donation, procurement and testing of human tissues and cells; the implementation of a traceability system; and specific rules on safety reporting and long-term follow-up. Under the Clinical Trials Regulation, special requirements apply to clinical trials conducted on minors and other persons not able to give informed legal consent. These requirements are intended to preserve the dignity of the trial subjects, confirm that the benefits of the trial outweigh the risks and ensure that subjects’ representatives give consent with as much involvement of the subject as possible. CHMP has also issued a guideline on quality requirements during the clinical trial period for investigational medicinal products containing biological or biotechnology-derived substances. The guideline describes quality documentation that should be submitted to the competent authority as part of the sponsor’s investigational medicinal product dossier (“IMPD”). The IMPD should include, among other things, (i) an adequate description of the process and process controls, including a flow chart of all successive steps and details of in-process testing and (ii) a description and justification of “any reprocessing during manufacture of the drug substance”. The guideline also recognizes that sponsors will improve and optimize their manufacturing processes during clinical development and describes the steps sponsors should take following these changes. Specifically, the sponsor must compare the quality attributes of the pre- and post-change biological active substances and relevant intermediates and conduct a comparability exercise where necessary. For first-in-human clinical trials, sponsors should use product representative of the material used during the non-clinical testing phase. Finally, with regard to characterization, the guideline requires details on the biological activity to be provided, recognizing that the extent of characterization data will further increase in later phases.

Study Design Considerations

General regulatory guidance on study design applies to biologics as well as small molecule medicines. According to the guidance, there is a “close, but variable correlation” between phase of development and type of study, but one type of trial can occur in several different phases. The guidance therefore identifies the most typical kind of study for each phase.

27

Table of Contents

Phase 1 usually involves the initial introduction of the investigational product into human subjects, and studies in this phase usually have non-therapeutic objectives. Specifically, Phase 1 studies typically investigate initial safety and tolerability, PK, PD and/or drug activity, to preliminarily determine the potential therapeutic benefit of a medicine. Phase 1 studies may be conducted in healthy volunteers or certain types of patients. If the medicine has significant potential toxicity (e.g., cytotoxic products), the trial will usually be conducted in patients.

The most typical Phase 2 study is a therapeutic exploratory study that explores efficacy in narrowly defined, relatively homogenous groups of patients. Initially, studies may use a variety of designs (e.g., concurrent controls and comparisons with baseline status). Subsequent Phase 2 trials usually are randomized and concurrently controlled, allowing for evaluation of the medicine’s safety and efficacy for a particular indication. A major goal of this phase is to determine the dose(s) for Phase 3 trials.

Phase 3 typically involves therapeutic confirmatory studies that are designed to verify the preliminary evidence obtained in Phase 2 and to provide a sufficient basis for marketing authorization. Phase 3 studies may also further explore the dose response relationship, or explore the drug’s use in wider populations, in different stages of disease, or in combination with another drug. With regard to medicines administered for long periods, extended exposure trials ordinarily occur during Phase 3, although the sponsor may start them in Phase 2.

To ensure that clinical trials in all three phases of development will be adequate to support a marketing authorization application (“MAA”), sponsors should design these trials with the MAA requirements in mind. Certain biologics products need to comply with the requirements set out in Part III of the Annex I to Directive 2003/63/EC (which amends the core EU medicines legislation, Directive 2001/83/EC), and advanced therapy medicinal products need to comply with the requirements described in Part IV of the Annex I to Directive 2003/63/EC.

Consultation with the European Medicines Agency

A sponsor may obtain, from the EMA, scientific advice regarding the development of a medicinal product. Although this advice does not bind the EMA and is not binding for purposes of a future MAA, it can be useful to guide developers generally in performing the appropriate preclinical and clinical tests for the product, or on more specific aspects such as guiding revisions to a clinical trial protocol. The EMA’s remarks will only address scientific issues and will generally focus on matters such as the selection of endpoints and comparators, the duration of treatment or follow-up and the design of pivotal studies. Advice also might address a sponsor’s proposal to deviate from a CHMP guideline. If the applicant decides not to follow the EMA’s advice, it should justify this decision in its MAA. EMA guidance details the procedures for requesting scientific advice. The fact that an applicant requests advice from EMA does not preclude it from also seeking advice from national competent authorities or from foreign regulators, such as the FDA. The process of obtaining advice from the national competent authorities is often less formal than requesting advice from the EMA, and such advice can prove helpful. Consequently, seeking such advice is a common choice among marketing authorization applicants. Generally, the parallel scientific advice procedure (a program shared by the EMA and FDA) is available for “important medicinal products”, that is, products that the EMA and FDA have identified as falling within therapeutic areas of overlapping interest (e.g., oncology products, vaccines and blood products) or products being developed for indications lacking development guidelines. The goal of these meetings is to provide clarity regarding the regulatory requirements of each region and the reasons for any differences between them. A sponsor requesting parallel scientific advice should authorize the agencies to exchange all information about the product, including trade secrets. After the parallel scientific advice procedure, each agency will provide its own independent advice on the questions at issue. There is no guarantee of harmonized advice or identical regulatory decisions on the approvability of the product.

European Marketing Authorization

In the European Economic Area (“EEA”), which includes the 27 member states of the EU plus Norway, Iceland and Liechtenstein, medicinal products can only be placed on the market after the grant of a marketing authorization. The MAA is based on the results of pharmaceutical tests, preclinical tests and clinical trials conducted on the medicinal product in question. There are two types of marketing authorizations:

28

Table of Contents

Under the procedures described above, before granting a marketing authorization, the EMA (through the CHMP) or the competent authorities of the member states of the EEA make an assessment of the risk-benefit balance of the medicinal product on the basis of scientific criteria concerning its quality, safety and efficacy.

The Marketing Authorization Application: Contents and Approval Standard

Many biologics fall under the scope of the centralized procedure, which, as mentioned above, is mandatory for medicines developed through biotechnological methods, such as recombinant DNA technology; controlled expression of genes coding for biologically active proteins in prokaryotes and eukaryotes, including transformed mammalian cells; and hybridoma and mAb methods. Gene therapy and cell therapy products are also subject to the centralized procedure as advanced therapy medicinal products. Nonetheless, some biologics are still approved at the member state level. For example, certain types of vaccines do not fall within the mandatory scope of the centralized procedure (although they may be eligible for the centralized procedure in the interest of public health). The EMA has published a guideline intended to harmonize the quality aspects to be included in summaries of product characteristics and patient information leaflets for human vaccines.

With respect to the centralized procedure, the approval standards for biotechnology products are the same as for chemically synthesized medicines. Both types of products must be safe and effective and have appropriate quality. Because of their special characteristics, however, biotechnology products must comply with several additional dossier requirements. For example, the applicant must thoroughly describe the manufacturing process and must: (i) provide information on the origin and history of the starting materials; (ii) demonstrate that the active substance complies with specific measures for preventing the transmission of animal and human spongiform encephalopathies; (iii) if cell banks are used, demonstrate that cell characteristics remain unchanged at the passage level for production (and beyond); (iv) provide information as to whether there are adventitious agents in seed materials, cell banks, pools of serum or plasma, and all other materials of biological origin, and, if it is not possible to avoid the presence of potentially pathogenic adventitious agents, show that further processing ensures elimination or inactivation of the agents; (v) if possible, base vaccine production on a seed lot system and established cell banks; (vi) in case of medicines derived from human blood or plasma, describe the origin, criteria and procedures for the collection, transportation and storage of the starting material; and (vii) describe the manufacturing facilities and equipment. Other special rules apply to certain types of biological medicines. For example, for plasma-derived medicinal products, the applicant must provide an information dossier, the Plasma Master File. MAAs for vaccines other than for influenza need to contain a Vaccine Antigen Master File. Special rules also apply to advanced therapy medicinal products, including gene therapies, somatic cell therapies and tissue-engineered products.

29

Table of Contents

Data and Market Exclusivity in the European Union

In the EU, new chemical entities (including both small molecules and biological medicinal products), sometimes referred to as new active substances, qualify for eight years of data exclusivity upon marketing authorization and an additional two years of market exclusivity. This data exclusivity prevents generic applicants from referencing the innovator’s pre-clinical and clinical trial data contained in the dossier of the reference product when applying for a generic marketing authorization, for a period of eight years from the date on which the reference product was first authorized in the EU. After such eight year period, a generic marketing authorization can be submitted, and the innovator’s data may be referenced, but no generic product can be marketed for a further two years. The overall ten-year period may be extended to a maximum of 11 years if, during the period of data exclusivity, the marketing authorization 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. Even if an innovative medicinal product gains the prescribed period of data exclusivity, another company may market another version of the product if such company obtained a marketing authorization based on an application with a complete and independent data package of pharmaceutical tests, preclinical tests and clinical trials.

Orphan Designation in the European Union

The European Commission is also able to grant orphan designation in respect of medicinal products. To qualify the medicinal product must be intended for the diagnosis, prevention or treatment of (i) a life-threatening or chronically debilitating condition affecting not more than 5 in 10,000 persons in the EU or (ii) a life-threatening, seriously debilitating or serious and chronic condition in the EU where without incentives it is unlikely that the marketing of the medicinal product in the EU would generate sufficient return to justify the necessary investment in its development. Further, no satisfactory method of diagnosis, prevention or treatment of the condition in question must exist in the EU or, if such method exists, the medicinal product must be of significant benefit to those affected by the condition.

Orphan medicinal products still remain subject to the same regulatory approval process, albeit that they are always assessed through the centralized procedure. Sponsors applying for orphan designation must use EMA’s secure online IRIS platform. However, sponsors of orphan medicinal products are eligible to benefit from a number of incentives offered, including certain assistance with development of the medicinal product, reduced fees for MAAs and protection from market competition once the medicinal product is authorized, as described below.

Where a marketing authorization in respect of an orphan medicinal product is granted, the European Commission, EMA and the competent authorities of the EU member states shall not, for a period of ten years, accept another application for a marketing authorization or grant a marketing authorization or accept an application to extend an existing authorization, for the same therapeutic indication, in respect of a similar medicinal product, to an authorized orphan product unless: (i) the holder of the marketing authorization for the original orphan medicinal product has given its consent to the second applicant; (ii) the holder of the marketing authorization for the original orphan medicinal product is unable to supply sufficient quantities of the medicinal product; or (iii) the second applicant can establish that its product is safer, more effective or otherwise clinically superior to the authorized orphan product. A “similar medicinal product” is defined as a medicinal product containing a similar active substance or substances as contained in an authorized orphan medicinal product, and which is intended for the same therapeutic indication.

All of the aforementioned EU rules are generally applicable in the EEA.

Reform of the Regulatory Framework in the European Union

The European Commission introduced legislative proposals in April 2023 that, if implemented, will replace the current regulatory framework in the EU for all medicines (including those for rare diseases and for children). In April 2024, the European Parliament adopted its position on the legislative proposals and, in June 2025, the Council of the European Union adopted its position. A common position on the text has been agreed upon on December 11, 2025, in the context of subsequent inter-institutional trilogue negotiations. The proposed revisions remain to be adopted, and are not expected to become applicable before 2028.

30

Table of Contents

Brexit and the Regulatory Framework in the United Kingdom

Following the end of the Brexit transition period on January 1, 2021 and the implementation of the Windsor Framework on January 1, 2025, the United Kingdom, or UK, is generally no longer subject to EU laws in respect of medicines. EU laws that were transposed into UK law through secondary legislation remain applicable in the UK; however, new EU legislation, such as the EU Clinical Trials Regulation, is not applicable in the UK. As of January 1, 2021, the Medicines and Healthcare products Regulatory Agency, or MHRA, is the UK's standalone medicines and medical devices regulator. As a result of the Northern Ireland Protocol, different rules applied in Northern Ireland than in England, Wales, and Scotland (together, "Great Britain", or GB) for a period following Brexit, with Northern Ireland continuing to follow certain aspects of the EU regulatory regime. However, on January 1, 2025, a new arrangement called the "Windsor Framework" came into effect and placed medicinal products supplied to Northern Ireland largely under the regulatory authority of the MHRA. The Windsor Framework removes EU licensing processes and certain EU labeling and serialization requirements for medicines supplied to Northern Ireland and introduces a UK-wide licensing process for medicines. In particular, the MHRA is responsible for approving medicinal products placed on the UK market, and the EMA no longer has a role in granting UK marketing authorizations. A single UK-wide MA will be granted by the MHRA for medicinal products to be sold in the UK, enabling products to be sold in a single pack and under a single authorization throughout the UK. In addition, the new arrangements require, for packs placed on the UK market on or after January 1, 2025, a "UK Only" label, indicating they are not for sale in the EU. However, although a separate authorization is required to market medicinal products in the UK, since January 1, 2024, the MHRA may rely on the International Recognition Procedure, or IRP, when reviewing certain types of MAAs. Pursuant to the IRP, the MHRA may take into account the expertise and decision-making of trusted regulatory partners (e.g., the medicines regulatory authorities in Australia, Canada, Switzerland, Singapore, Japan, the United States and the EMA in the EU), when considering an application for a UK marketing authorization.

Other government regulation in the European Union and United Kingdom

The EU and the EU member states and the U.K. have extensive laws and regulations relating to a variety of other topics that would be of relevance for us if we are active in the EU and U.K., including but not limited to laws and regulations regarding data privacy, drug pricing and reimbursement, advertising and interactions with healthcare professionals.

Other Jurisdictions

In addition to regulations in the United States and the EU, we may be subject to a variety of regulations in other jurisdictions governing, among other things, clinical trials and any commercial sales and distribution of our product. As the United Kingdom is no longer a member state of the EU, this may also apply to the United Kingdom. Whether or not we obtain FDA approval for a product, we must obtain approval from comparable regulatory authorities in foreign countries before we can commence clinical trials in such countries and the approval of the regulators of foreign countries before we may market products in such countries. The approval process and requirements governing the conduct of clinical trials, product licensing, pricing and reimbursement vary greatly from place to place, and the time may be longer or shorter than that required for FDA approval.

Acceptance of Foreign Clinical Trials in the United States and the European Union

The FDA has issued regulations governing its acceptance of foreign clinical data not conducted under an IND to support IND applications or marketing authorizations, such as BLAs. FDA may accept a well-designed, well-conducted, non-IND foreign study as support for an IND or marketing application if the study was conducted in accordance with GCP and if FDA is able to validate the data from the study through an onsite inspection, if necessary. Where a marketing application is based solely on foreign data, additional requirements apply, including a demonstration that the foreign data are applicable to the U.S. population and U.S. medical practice.

EU Directive 2001/83/EC allows for clinical trials conducted outside the EU to be taken into consideration during the review of a marketing authorization in the EU if such trials have been designed, implemented and reported based on principles equivalent to those of the EU Clinical Trials Regulation, including with regard to good clinical practice and ethical principles. Moreover, they should comply with the ethical principles outlined in the Declaration of Helsinki. The

31

Table of Contents

applicant must submit a statement declaring such compliance as part of the marketing authorization. In April 2012, the EMA published a reflection paper on ethical and GCP aspects of clinical trials of medicinal products conducted outside the EU/EEA and submitted in MAAs to EU regulatory authorities. The EMA has called for increased cooperation between international regulatory authorities involved in the supervision of clinical trials and has put forth other proposals to address these issues.

Manufacturing and Source of Supply

We do not have any manufacturing facilities. We currently rely, and expect to continue to rely, on third parties for the manufacture of our product candidates for preclinical studies and clinical trials, as well as for commercial manufacture if our product candidates receive marketing approval. To date, we have obtained materials for clinical trials and non-clinical studies from third-party manufacturers who are suppliers to us. We intend to identify and qualify additional contract manufacturers to provide commercial scale manufacturing prior to submission of an NDA or BLA to the FDA.

Employees and Human Capital Management

As of December 31, 2025, we had 57 full-time employees, 16 of whom hold M.D. or Ph.D. degrees and 23 of whom hold other advanced degrees. Of our total workforce, the majority are engaged primarily in research and development, and the remainder are engaged primarily in executive, finance and accounting, and administrative functions. As of December 31, 2025, 56 employees are located in the United States and 1 employee is located in the United Kingdom. None of our employees are represented by labor unions or covered by collective bargaining agreements.

Corporate Culture

Our values – commitment, communicate, collaborate, competence and courage – are built on the foundation that the employees we hire, and the way we treat one another, promote creativity, innovation and productivity, which spur our success. This culture depends in large part on our ability to attract, retain and develop a diverse population of talents and high-performing employees at all levels of our organization. Providing market competitive pay and benefit programs, opportunities to participate in the success they help create, while engaging employees in important dialogue regarding organization performance, we create a culture of inclusion in which all colleagues have the opportunity to thrive. The success of our business is fundamentally connected to the well-being of our employees.

Compensation and Benefits Program

Our compensation program is designed to attract and reward talented individuals who possess the skills necessary to support our business objectives, assist in the achievement of our strategic goals and create long-term value for our stockholders. We provide all of our employees with what we consider to be a very competitive mix of compensation and insurance benefits, as well as participation in our equity programs.

Hybrid Culture

Currently we have a hybrid workplace, which means that we evaluate and determine the optimal work arrangements for our employees on an individual basis including full-time in office, part-time in office or remote depending on our needs and the responsibilities of each employee. This approach allows us to maintain flexibility and retain the best talent for the roles that are the most critical to our strategy and success.

Available Information

Our stock is traded on the Nasdaq Global Market (“Nasdaq”) under the symbol “ALT”. Our principal executive offices located at 910 Clopper Road, Suite 201S, Gaithersburg, Maryland 20878. Our telephone number is (240) 654-1450, and our Internet website is www.altimmune.com and our investor relations website is located under the “Investors” tab. The information on, or that can be accessed through, our website is not part of this Annual Report and is not incorporated by reference herein.

32

Table of Contents

We make available our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, and amendments to these reports, free of charge through our website (www.altimmune.com) as soon as reasonably practicable after we electronically file such material with, or furnish such material to, the SEC. We also make available on our website reports filed by our executive officers and Directors on Forms 3, 4, and 5 regarding their ownership of our securities. Our Code of Business Conduct and Ethics, and any amendments to our Code of Business Conduct and Ethics, are also available on our website under the “Investors” tab.

The SEC maintains a website that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC at www.sec.gov.

​