Atea Pharmaceuticals : Q1 26 IR Slide Deck 5 12 26 FINAL

Published: 2026-05-12 16:14:37 ET AVIR

Published on 05/12/2026 at 04:14 pm EDT

May 12, 2026

Focused Antiviral Pipeline with De-risked Phase 3 Program

Program

Therapeutic/ Indication

Flaviviridae Hepatitis C Virus (HCV)

Fixed Dose Combination:

Bemnifosbuvir (BEM) Nucleotide Prodrug Ruzasvir (RZR)

NS5A Inhibitor

Hepeviridae Hepatitis E Virus (HEV)

Nucleotide Prodrug AT-587

Preclinical

Phase 1

Phase 2

Phase 3

Milestone

Ph 3 C-BEYOND trial

(US / Canada) enrollment completed (n=> 880); topline results expected mid-2026

Ph 3 C-FORWARD trial (outside North America) patient full enrollment (n=~880) expected mid-2026; topline results expected year-end 2026

Phase 1 initiation targeted mid-2026

Cash and investments: $256.0 million at 3/31/26

Cash runway anticipated through 2027

Target Profile

BEM/RZR: Potential Best-in-Class Treatment for HCV

First Head-to-Head Phase 3 Program in HCV

Potefitial Best-ifi-Class

Treatmefit for HCV

Robust Phase 2 Results

Achieved Primary Efidpoifits

Phase 3 BEM / RZR vs.

Active Comparator

HCV product candidate is regimen of BEM, the most potent nucleotide inhibitor*, and RZR, a highly potent NS5A inhibitor*

Demonstrated:

⯈ Efficacy and tolerability

⯈ Convenient dosing with short

8-week treatment duration** and no food effect

⯈ Low risk of drug-drug interactions, including proton pump inhibitors and statins

Phase 2 results (n=275) demonstrated BEM and RZR combination regimen achieved primary endpoints of sustained virologic response and safety

G8% sustained virologic response at 12 weeks post-treatment (SVR12)

No drug-related serious adverse events

Chronic HCV, patients stratified by cirrhosis status and genotype, HIV-co-infected allowed

Global Clinical Phase 3 program:

⯈ First head-to-head against sofosbuvir (SOF) /velpatasvir (VEL)†

⯈ 2 trials with ~1,760 total patients; up to 240 sites globally

5 *BEM in vitro studies; RZR preclinical and clinical studies; ** in non-cirrhotic patients; †brand name product marketed as Epclusa®

Global Phase 3 Program

Global HCV Phase 3 Program: C-BEYOND (US/Canada) and C-FORWARD (Outside North America)

12 weeks SOF/VEL FDC

8 weeks BEM/RZR FDC

Non-Cirrhotic

US / Canada Trial Enrollment Completed Outside North America

Trial N = ~700

1:1

Open-label: BEM/RZR Regimen vs Active Comparator in Chronic HCV Patients Randomized (1:1)

Chronic HCV, patients stratified by cirrhosis and genotype, HIV co-infected allowed, prior DAA excluded

Two Phase 3 Trials:

N= >880 trial US /

Canada

(C-BEYOND)

N= ~880 trial Outside North America

(C-FORWARD)

N= ~1,760 total patients

Cirrhotic

US / Canada Trial Enrollment Completed Outside North America Trial N = ~175

Primary Endpoint - Encompasses SVR12 in All Arms*

0 8

12 weeks SOF/VEL FDC

12 weeks BEM/RZR FDC

Treatment Duration

(Weeks)

1:1

Post-Treatment

(Weeks)

Primary Endpoint

No cirrhosis: 8 weeks of BEM/RZR vs 12 weeks of active comparator

Compensated cirrhosis: 12 weeks of BEM/RZR vs active comparator

SVR = Sustained Virologic Response, FDC = Fixed Dose Combination (Dose 2 tb QD BEM/RZR), SOF/VEL = sofosbuvir/velpatasvir

*HCV RNA < lower limit of quantification 24 weeks from start of treatment

On Track: Global HCV Phase 3 Program

C-BEYOND

C-FORWARD

~120 sites in US and Canada

Enrollment completed n= >880

Cirrhotic population target achieved

Topline results expected mid-2026

~120 sites in 17 countries outside of North America

Enrollment completion expected mid-2026

Topline results expected year-end 2026

Enrolled patient population representative of genotypes and demographics in North

America to support a broad label

95% of enrollment completed; continuing to enroll less frequent genotypes such as 4, 5, and 6 to support a broad label

Phase 3 Endpoints, Patient Populations and Analyses

SVR at Week 24 mITT population

SVR at Week 24 PP population

Key Secondary Efficacy Endpoint

SVR at Week 24 PP population

SVR at Week 24 mITT population

Primary Efficacy Endpoint

C-FORWARD (Outside North America)

C-BEYOND (US/Canada)

Modified Intent-To-Treat (mITT)

Per-Protocol (PP)

Population:

All randomized and dosed

All randomized, study drug compliant (≥80% pill count)

and SVR assessment at Week 24 (or with SVR12)

Considerations:

Overall SVR rate will reflect non-drug related discontinuations (as rate does not consider compliance or lost to follow-up)

Overall SVR rate will better reflect true efficacy

(as rate does consider compliance and lost to follow-up)

Ph 2 SVR12 rates w/above handling*

95%

98%

Modified intent-to-treat is FDA preferred and per-protocol is EMA preferred

The same methods for assessing non-inferiority will be conducted in both Phase 3 studies and in both populations

The reported overall SVR (primary analysis) for each study will differ because of the population used

Phase 3 studies powered 90% with a 5% non-inferiority margin for expected rate approximating 95% in mITT population

G *post-hoc analyses

BEM/RZR Market Research

US New Chronic HCV Infections Continue to Increase Despite Availability of Curative Direct-Acting Antivirals

Up to 4M People Estimated to be Infected in US1

180,000

160,000

Number of US Patients

140,000

120,000

100,000

80,000

60,000

40,000

20,000

2020 2021 2022 2023 2024 2025

Out of ~160,000 new chronic infections,

only ~85,000 treated annually2,3

Most countries worldwide, including US, not on track to achieve WHO's goal of HCV elimination by 2030. Current estimates suggest 2050 at earliest2

Chronic HCV is a leading cause of liver

cancer in the US4

CDC: https://www.cdc.gov/hepatitis/hcp/clinical-overview/index.html

The CDA Foundation. Hepatitis C - United States. Lafayette, CO: CDA Foundation 2025. Available from https://cdafound.org/Polaris/database-query (accessed 15 Apr 2026)

11 4. CDC: https://www.cdc.gov/hepatitis-c/about/index.html (accessed 24 Apr 2026)

Annual New HCV Infections in US Exceed Treatments

Test-and-Treat Model of Care Can Expand Diagnosis and Treatment

~160 K

Annual New Chronic Infections2

HCV Infections Growing Faster Than Treated Patients in US

~4 M

Infected Individuals1

Expansion of Test-and-Treat Model Can Increase Number of Patients Treated and Accelerate HCV Elimination In US

TEST TREAT AND

Rapid diagnosis and treatment at the same time

Reduces barriers to treatment prescribing / initiation

Therapy with short treatment duration with low-risk of drug-drug interactions optimal for physicians and patients

Bipartisan legislative efforts underway with goal to eliminate HCV in US with test-and-treat model of care

~85 K

Annual Treatments with Epclusa or Mavyret3

~$1.3 B

US Net Sales in 20254

1. CDC: https://www.cdc.gov/hepatitis/hcp/clinical-overview/index.html 2. The CDA Foundation, Lafayette, CO 2025. Hepatitis C - United States. Available from

12 https://cdafound.org/Polaris/database-query/ (Accessed 4/15/2026) 3. IQVIA 2025 4. U.S. Net Sales of Mavyret, Epclusa (and its authorized copy) from AbbVie

and Gilead 2025 Annual Reports

2025 US HCV DAA Payer Landscape

BEM/RZR High Likelihood to Be Added to Existing Formularies in All Payer Segments

HCV Patients Getting Access From All Payer Segments

High Likelihood of BEM/RZR Being Added to Existing Formularies at Parity Net Pricing Across Payer Segments2

HCV Prescriptions By Payer1

21%

52%

27%

Commercial

Medicare

Medicaid

Extremely Likely

Extremely Unlikely

17%

28%

39%

6% 11%

Commercial

(n=18)

29%

36%

29%

Medicaid

(n=14)

20%

53%

20%

Medicare

(n=15)

Likelihood of Parity

Access at Parity Net Pricing

13 1. Atea custom project using IQVIA LAAD data 2026 2. Atea Custom Market Research, Formulary Insights, June 2024

Competitive Positions in the US DAA High Value HCV Market

Different Payer Segments Drive Epclusa and Mavyret Prescriptions

Payer Distribution by Product1

Medicaid

Medicare

Commercial

Mavyret

Epclusa

SOF/VEL

(authorized copy of Epclusa)

High Proportion of Mavyret Rxs is from Medicaid

High Proportion of Epclusa Rxs is from Medicare

11%

26%

36%

26%

18%

54%

56%

10%

63%

14 1. Atea custom project using IQVIA LAAD NBRx data 2025

Highly Attractive BEM/RZR Commercial Profile

BEM/RZR Has Potential to Gain Significant Market Share

76% of High DAA Prescribers Extremely Likely to Prescribe BEM/RZR1

48%

Predicted Share of

Non-Cirrhotic Patients2

4G%

Predicted Share of

Compensated Cirrhotic Patients2

15 1. Atea Custom Market Research, IQVIA, June 2025; 2. Predicted share of patients between BEM/RZR, Epclusa, and Mavyret

BEM/RZR Commercial Readiness

Commercial Launch Supply Manufacturing in Place & Marketing Planning Underway

Specialty Commercial Planning

Launch Supply Following NDA Approval

All components and processes for large

scale manufacturing in place

Commercial launch supply underway with low cost of goods relative to net price

Blister card for convenience and patient adherence

Commercial Supply

Concentrated Prescriber Base

Specialty care sales force required

- ~7,800 prescribers write

~80% of direct acting antiviral prescriptions1

Only 2 competitors with no other product candidates in clinical development

Sales C MSL Headcount ~75

Sales Reps

Sales Management MSLs

Expected Short Time to Profitability Post-Launch

16 1. IQVIA 2025

Product Candidate AT-587

Hepatitis E Virus (HEV) - an Acute and Chronic Liver Disease Significant Unmet Need for Patients with Chronic HEV Infection Who are Immunocompromised or at High Risk

HEV Waterborne transmission

GT 1,2 causes epidemics of acute,

mostly self-limiting hepatitis in

developing countries

HEV-1 HEV-2

HEV

GT 3,4

Foodborne transmission causes chronic hepatitis in immunocompromised patient populations which can rapidly progress to cirrhosis

HEV-3

HEV-4

18 Adapted from Khuroo MS, Khuroo MS, Khuroo NS. Hepatitis E: Discovery, global impact, control and cure. World J Gastroenterol 2016; 22(31): 7030-7045

Chronic HEV Infection Among Immunocompromised Individuals Can Rapidly Progress to Cirrhosis

15%

of infected SOT recipients with chronic

HEV rapidly develop cirrhosis in 3-5 years2

At-Risk Populations1

Solid organ transplant recipients

No approved HEV treatments

Hematopoietic stem cell transplant (HSCT) recipients

Patients with hematologic malignancies

Patients with pre-existing liver disease

Step Current Interventions3 Rationale Risks

First Line Reduce Immunosuppression Restore Host Immunity Organ Rejection / Reinfection

Second Line Ribavirin (3 months) Direct Antiviral Effect Not Approved / Side Effects / Intolerance

Guideline Differences

WHO: Focus on Acute HEV

EASL: Focus on Chronic HEV

Reflects Distinct Local Epidemiology

March 2026 Roche launched a qualitative in-vitro diagnostic for detecting and differentiating HIV, HBV, HCV and HEV

Alexandrova R, et al. HEV Infection Among Immunocompromised Individuals: A Brief Narrative Review. Infection and Drug Resi stance. 2014;17 2. Kamar N et al. Factors Associated

1G with Chronic Hepatitis in HEV with SOT. Gastroenter. 2011(140) 3. Dalton H et al. EASL Clinical Practice Guidelines on hepatitis E virus infection. J Hepatology. 2018;16. 1256-1271

Commercial Opportunity of $750M-$1B* for the Treatment of HEV Infection Among High-Risk Populations in US & EU

No Approved Treatment

Annual number

of at-risk populations

Solid Organ Transplant (SOT)1 Recipients

~80K

Potential Treatment Population of

~13.5K Patients Annually

Chronic HEV

HSCT Recipients2

~37K

Commercial Opportunity

$750M-$1B*

~3%**

of at-risk patients develop

chronic HEV4,5

Hematologic Malignancies3

~334K

*Assumes pricing estimates of

$200K per course of therapy based on similar HDV pricing

*Assumes ~30% treated

**Assumes similar incidence rates of chronic HEV in HSCT and Hematologic Malignancies as with SOT

1. 2023 SOT patients transplanted in US, EU C UK. Newsletter Transplant: International Figures on Donation and Transplantation 2023. EDQM Vol 29 2024. 2. 2022 HSCT patients transplanted in EU C UK. Passweg, J.R., et al. Utilization of hematopoietic cell transplantation and cellular therapy technology in Europe and associated Countries. Bone Marrow Transplant 60, 227-236 (2025) and 2023 HSCT patients transplanted in US. Health Resources and Service Administration. 3. 2022 Leukemia and non-Hodgkins Lymphoma patients in

20 US, EU C UK. WHO International Agency for Research on Cancer. https://gco.iarc.who.int/today/en Accessed 10/20/25. 4. Hansrivijit P. Et al. HEV in SOT Recipients. World J Gastroenterol. 2021(27). 12. 5. Kamar N et al. Factors Associated with Chronic Hepatitis in HEV with SOT. Gastroenter. 2011(140).

AT-587: Potent Inhibition of Hepatitis E Virus Replication In Vitro

Compound Mean ± SD (nM)

AT-587

79.6 ± 29.2 (n=12)

BEM

458.1 ± 140.7 (n=3)

SOF

5,129 ± 985 (n=3)

Ribavirin

12,551 ± 256 (n=3)

Note: Antiviral activity of AT-587 confirmed in primary human hepatocytes infected with HEV

Low protein binding limits the effect of human serum on antiviral activity of AT-587 (2.4-fold shift in EC50)

Plasma metabolites of AT-587 are inactive against HEV-3 (EC50 values > 10 uM)

AT-587: low potential for drug-drug interactions (DDIs) based on in vitro data to date

AT-587 for HEV

Preclinical Profile Supports Advancement to First-in-Human Study

Cells

AT-9010 (BEM)

AT-9068 (AT-587)

Human hepatocytes

1,360

3,920

No inhibition of α, β, γ human DNA polymerases by active triphosphate (AT-9068)

Negative in GLP in vitro genetox assays (Ames, in vitro micronucleus)

No hERG inhibition at clinically meaningful concentrations in in vitro GLP assay

Negative in GLP phototoxicity assay

No toxicity to human iPS cardiomyocytes and bone marrow CD34+ cells

CTA-enabling GLP toxicology and safety pharmacology studies completed

AT-587: Human Pharmacokinetics Predicted to Achieve Drug Exposure Above the In Vitro Antiviral Activity

Predicted human plasma exposure of AT-587 and AT-2485 (the surrogate of the active intracellular triphosphate metabolite) after oral administration of 600 mg QD

EC50 of AT-587 (100 ng/ml ~ 300 nM) AT-587

AT-2485

AT-587 First-in-Human Study

Population: Healthy adult volunteers

Objectives:

Safety, tolerability and

pharmacokinetics (PK)

Design:

Randomized, double-blind, placebo-controlled

Part A

Single Ascending Dose (SAD)

Up to 4 cohorts, sequentially evaluating increasing single doses of AT-587; embedded food effect

Part B

Multiple Ascending Dose (MAD)

Up to 3 cohorts, sequentially evaluating increasing multiple doses of AT-587

Progression based upon review of emerging safety and PK data

Flexibility to adapt doses based on accumulating data

First Quarter 2026 Results

Financial Update

Upcoming Key Milestones Across Antiviral Pipeline

BEM/RZR REGIMEN - PHASE 3 PROGRAM FOR HCV

Ongoing

Two Phase 3 Trials (C-BEYOND and C-FORWARD)

Mid-2026

Completion of C-FORWARD

patient enrollment

Topline Phase 3 results for C-BEYOND

Year-end 2026

Topline Phase 3 results for C-FORWARD

2027

Anticipated Q1 NDA submission

2026

2027

AT-587- PROGRAM FOR HEV

Ongoing

CTA enabling studies completed; preparing to initiate first-in-human study

Mid-2026

Phase 1 clinical study

2H 2026

Initiation of

POC clinical study

2H 2027

Initiation of Phase 2/3 trial

Cash and investments: $256.0 million at 3/31/26

Cash runway anticipated through 2027

225 Franklin Street

Suite 2100 Boston MA USA 02110 https://www.ateapharma.com

Disclaimer

Atea Pharmaceuticals Inc. published this content on May 12, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on May 12, 2026 at 20:13 UTC.