AVIR

• HCV Clinical Development Milestones

• The CBEYOND Phase III trial of BAM/Rusosvir (BMR-ZR) for HCV in North America met all primary and secondary endpoints, demonstrating statistical non-inferiority to standard-of-care Abclusa with a 93.9% sustained virologic response (cure) rate vs 94.8% for Abclusa in the modified intent-to-treat (MITT) population
• BMR-ZR achieved 93.5% cure rate in 8 weeks of treatment for non-cirrhotic patients (vs 94.6% in 12 weeks for standard of care), and a matching 95.4% cure rate for compensated cirrhotic patients treated for 12 weeks; safety profiles are comparable between arms, with no treatment-related serious adverse events or treatment discontinuations
• The second global Phase III trial C-Forward, conducted outside North America, is fully enrolled with over 880 patients, and top-line results are on track to release in early Q1 2027; the trial will provide confirmatory efficacy data across understudied HCV genotypes to support a global regulatory submission
• BMR-ZR has a best-in-class profile: pangenotypic, once-daily, protease-inhibitor-free, with low drug-drug interaction (DDI) risk, no food effects, and shorter 8-week treatment for non-cirrhotic patients, addressing key unmet needs for complex, poorly adherent patient populations

• HEV Pipeline Progress

• The first-in-human Phase I trial of AT587, a potential first-in-class direct-acting antiviral for chronic Hepatitis E (which has no currently approved therapies), was initiated in July 2026; the first dose cohort has been completed, and the trial is progressing to subsequent cohorts
• The Phase I trial is randomized double-blind placebo-controlled with dose escalation, evaluating safety, tolerability, and pharmacokinetics in healthy volunteers, with proof-of-concept data expected in 2027

• Commercial Opportunity and Readiness

• Contrary to common market perception that the HCV market is declining, management notes that annual new HCV diagnoses outpace treatments, leading to a growing total infected population approaching 4 million in the U.S., creating an expanding addressable market
• BMR-ZR's profile is optimized for the growing test-and-treat model of care, which enables same-visit diagnosis and treatment to reduce patient attrition and expand treatment access; 76% of high-volume HCV prescribers report they are extremely likely to prescribe BMR-ZR, with projected peak U.S. net revenue potential exceeding $700 million
• All manufacturing processes and launch supply are in place; a focused specialty sales force of 75-100 representatives will cover 80% of U.S. HCV prescriptions, with low cost of goods supporting rapid path to profitability post-launch

• Financial Position

• The company ended Q2 2026 with $219.5 million in cash and marketable securities, with sufficient runway to fund all planned milestones through 2027

• Top-line results from the C-Forward Phase III HCV trial are expected in early Q1 2027, with U.S. NDA submission for BMR-ZR anticipated in Q2 2027 following positive C-Forward results

• Proof-of-concept data for the AT587 HEV program is expected in 2027, with an anticipated commercial launch of BMR-ZR in mid-2028
• Management expects BMR-ZR will reach profitability a short time after its mid-2028 launch, with peak annual U.S. net sales potential exceeding $700 million
• The company's current cash balance of $219.5 million as of June 30 2026 is projected to provide cash runway extending through 2027 to deliver all planned near-term milestones for both the HCV and HEV programs
• In H2 2026, the majority of spending will remain focused on advancing the HCV program, completing C-Forward, preparing regulatory filings, and advancing pre-launch commercial readiness activities

Atea Pharmaceuticals is a clinical-stage biotech company with two primary product segments: the Hepatitis C (HCV) pipeline segment and the Hepatitis E (HEV) pipeline segment. As of Q2 2026, 100% of the company's operating spend is allocated to pipeline development, with no commercial revenue generated yet. Approximately 85-90% of total spending in H1 2026 went to the HCV Phase III program, with the remaining 10-15% directed to the HEV preclinical and Phase I startup activities. Cash and marketable securities totaled $219.5 million as of June 30, 2026. H1 2026 R&D expenses increased year-over-year due to higher external costs for the HCV Phase III program and HEV startup activities, partially offset by lower internal stock-based compensation and payroll costs. H1 2026 G&A expenses decreased year-over-year due to lower salaries, wages, and stock-based compensation.

• All forward-looking statements around trial results, regulatory approval, and launch timelines are subject to inherent clinical and regulatory risks; actual results may differ materially from current projections, as outlined in the company's SEC filings

• The success of BMR-ZR depends on positive top-line results from the C-Forward trial, which is testing efficacy across a different geographic and genotypic patient population than the completed CBEYOND trial
• Widespread adoption of the test-and-treat care model, which BMR-ZR is positioned to benefit from, depends on ongoing policy changes and payer approval for full same-visit dispensing that have not yet been finalized nationally
• Recent U.S. pricing reforms (Inflation Reduction Act, Medicare Part D changes, 340B program adjustments, and Medicaid MFN pricing rules) create uncertainty around net pricing and market dynamics for all HCV branded therapies, with final impacts still evolving
• The company has not yet generated any commercial revenue, and all value is dependent on successful regulatory approval and commercial adoption of its lead product candidate

Q: How will BMR-ZR's novel mechanism of action (MOA) be reflected in labeling, and what steps are needed to enable BMR-ZR use in the test-and-treat model that eliminates extra refill steps? / A: Full data on the novel MOA has not been released yet. Management will share the complete dataset with the FDA in early 2027 and present findings at scientific conferences before finalizing labeling language. For test-and-treat, BMR-ZR will offer both blister packs and bottles for convenient same-visit dispensing. Payers in states that already implement test-and-treat currently allow full dispensing of all required doses at diagnosis, and national adoption will require broader policy changes that are already underway, with BMR-ZR's low DDI and short course making it optimal for this model.

Q: What is the timeline and key evidence needed to add BMR-ZR to the AASLD simplified HCV treatment guidelines? / A: The guideline panel prioritizes best-in-class product profiles, and BMR-ZR's 8-week course for most patients, favorable safety, and low DDI profile aligns with current panel priorities. Once BMR-ZR receives regulatory approval, management expects it will be straightforward to add BMR-ZR to the simplified treatment algorithm. Management also noted that high clinical site demand allowed C-Forward to fully enroll 900 patients across 17 countries in less than 8 months, reflecting widespread clinical interest in the regimen.

Q: How does the positive CBEYOND non-inferiority result affect confidence in the upcoming C-Forward readout, how do C-Forward patient populations differ, and what is the impact of recent U.S. HCV pricing reforms on the competitive landscape? / A: C-Forward has a different genotype and patient mix enriched for understudied genotypes 1b, 3, 4, 5, and 6 not common in North America, with less injection drug use-related transmission and expected higher patient adherence than the CBEYOND population; existing Phase II data already shows strong efficacy across these genotypes, so management is confident in favorable results. For pricing reforms, the impacts vary by competitor based on their payer mix, but overall effects are less dramatic than many analysts expect, and proposed 340B changes are expected to be net favorable to new market entrants by eliminating double discounting.