Atea Pharmaceuticals Advances Antiviral Pipeline with Promising Drug-Drug Interaction Data and First-in-Class HEV Candidate
核心洞察
Atea Pharmaceuticals presented Phase 1 results demonstrating that its hepatitis C virus (搜索) treatment regimen BEM/RZR has a low risk of drug-drug interactions with commonly used medications including omeprazole and rosuvastatin.
The company's experimental hepatitis E virus (搜索) treatment AT-587 (搜索) showed 30 to 150-fold greater potency than existing off-label treatments in preclinical studies, with plans to enter first-in-human trials mid-2026.
These developments address significant unmet medical needs, as approximately 80% of HCV patients take multiple medications concurrently, and there are currently no approved therapies for chronic HEV infections.
Atea Pharmaceuticals presented compelling Phase 1 data at the European Association for the Study of the Liver (EASL) Congress 2026 demonstrating that its fixed-dose combination regimen of bemnifosbuvir and ruzasvir (BEM/RZR) for hepatitis C virus (搜索) (HCV) treatment maintains a favorable drug-drug interaction profile with commonly prescribed medications. The company also unveiled preclinical results for AT-587 (搜索), a potential first-in-class direct-acting antiviral for hepatitis E virus (搜索) (HEV) treatment.
HCV Treatment Advances Address Real-World Patient Needs
The Phase 1 studies evaluated BEM/RZR's interactions with medications frequently used by HCV patients, addressing a critical clinical concern. According to US healthcare providers treating HCV patients, approximately 80% of patients manage multiple medications concurrently, making drug-drug interactions a significant treatment complication.
In a study of 20 healthy adults, BEM/RZR demonstrated safety and tolerability when administered alone or with omeprazole, a proton pump inhibitor commonly prescribed for gastroesophageal reflux disease. Omeprazole at 20 mg did not affect plasma exposure to BEM/RZR, while the 40 mg dose administered two hours before BEM/RZR only slightly reduced plasma exposure. Importantly, BEM/RZR did not meaningfully affect omeprazole's pharmacokinetic profile.
Additional Phase 1 data from studies with digoxin (n=18) and rosuvastatin (n=18) showed that BEM/RZR has low potential to inhibit important drug transporters P-gp (搜索), BCRP (搜索), and OATP1B1 (搜索)/1B3. While BEM/RZR slightly increased plasma exposure of both drugs, the geometric mean ratio remained below 2, indicating no clinically meaningful inhibition. All treatment-emergent adverse events were mild in severity, and no dose adjustments are needed for drugs that are substrates of these transporters when co-administered with BEM/RZR.
"These Phase 1 results reinforce the potential of the regimen of BEM/RZR to simplify treatment for patients and healthcare providers and address the evolving needs of today's patients living with HCV," said Jean-Pierre Sommadossi, PhD, Chief Executive Officer and Founder of Atea Pharmaceuticals.
Breakthrough HEV Treatment Shows Superior Preclinical Activity
Atea's AT-587 (搜索) demonstrated remarkable preclinical efficacy against HEV, a virus that causes an estimated 20 million acute infections annually worldwide. In vitro studies showed AT-587 was 30 to 150-fold more potent against HEV than sofosbuvir and ribavirin, which are currently used off-label with limited efficacy and tolerability.
The oral nucleotide analog showed no toxicity in vitro studies and demonstrated activity against multiple viruses including flaviviruses, rubella, and chikungunya. In HEV-3-infected gerbil models, treated groups showed significantly lower HEV RNA levels in fecal samples compared to controls, with viral loads in liver and intestinal samples also significantly reduced.
Notably, AT-587 (搜索) retained high potency against ribavirin (G1634R) and sofosbuvir (A1343V) clinical resistance strains in vitro, differentiating it from existing off-label treatment options.
Addressing Critical Unmet Medical Needs
Chronic HEV genotype 3 and 4 infections have emerged as potentially life-threatening conditions in immunocompromised individuals, including solid organ and hematopoietic stem-cell transplant recipients and patients with hematologic malignancies (搜索). In these vulnerable populations, chronic HEV can progress to cirrhosis (搜索) within three to five years.
"There is a critical gap in the care of patients with chronic HEV with no approved therapies, leaving vulnerable populations including transplant recipients and other immunocompromised patients at risk for rapid disease progression to cirrhosis (搜索)," Dr. Sommadossi noted.
Each year in the US and Europe, 3% of approximately 450,000 patients with underlying medical conditions are at risk of developing chronic HEV. Currently, no approved antiviral therapy exists for HEV, creating an urgent unmet medical need that AT-587 (搜索) could potentially address.
Pipeline Progression and Clinical Timeline
Atea plans to advance AT-587 (搜索) into first-in-human studies mid-2026, marking a significant milestone for the potential first-in-class HEV treatment. The company's HCV program continues with ongoing Phase 3 trials C-BEYOND and C-FORWARD evaluating the BEM/RZR regimen.
Bemnifosbuvir has been administered to over 3,000 subjects and demonstrated tolerability at doses up to 550 mg for durations up to 12 weeks. Ruzasvir has been given to over 2,800 HCV-infected patients at daily doses up to 180 mg for 12 weeks with a favorable safety profile. Both compounds support once-daily dosing regimens.
The global HCV burden remains substantial despite available direct-acting antivirals, with an estimated 50 million people worldwide chronically infected and approximately one million new infections annually. In the US, approximately four million people have HCV, with new infections outpacing treatment rates.