Hepatitis C Virus (HCV) Phase 2 Update — New Results
Phase 2 HCV Combination Study: Atea is currently conducting a global Phase 2 clinical trial of bemnifosbuvir, an oral nucleotide polymerase inhibitor,
in combination with ruzasvir, an oral NS5A inhibitor, in treatment-naïve, HCV-infected patients either without cirrhosis or with compensated cirrhosis. This
study is designed to evaluate the safety and efficacy of eight weeks of treatment with the combination consisting of once-daily bemnifosbuvir 550 mg and ruzasvir 180 mg. Up to approximately 280
HCV-infected, treatment-naïve patients across all genotypes (GT), including the lead-in cohort of 60 patients without
cirrhosis, are expected to be enrolled in this Phase 2 clinical trial. The primary endpoints of the study are safety and sustained virologic response (SVR) at Week 12 post-treatment (SVR12). Other virologic endpoints include virologic failure, SVR
at Week 24 post-treatment (SVR24) and resistance.
Final results from the 60 patient lead-in cohort confirmed a
98% SVR4 rate across GT from 58 of 59 patients. These results, which are consistent with the initial results from this cohort announced in January 2024, include a patient with poor adherence who did not achieve SVR4 and exclude one patient who
did not attend the Week 4 post-treatment follow-up. The SVR4 rate exceeded the protocol-defined efficacy criterion of ≥90% SVR4 for continuing the study.
As a result, in January 2024 patient enrollment was reinitiated for up to 220 patients in the study, including patients with cirrhosis. Final SVR12 results
from all patients enrolled in the Phase 2 study are anticipated in the second half of 2024.
In the lead-in
cohort, very rapid viral kinetics were observed with viral load for each patient near or below the lower limit of quantification (LLOQ) at four weeks of treatment, which is supportive of an eight-week treatment regimen for the combination of
bemnifosbuvir and ruzasvir. All 60 patients in the lead-in cohort achieved viral load below the LLOQ by the end of the eight-week treatment.
The combination of bemnifosbuvir and ruzasvir in the lead-in cohort was generally safe and well-tolerated and there
were no drug related serious adverse events, no treatment discontinuations and adverse events were mostly mild.
COVID-19 Phase 3 SUNRISE-3 Update
SUNRISE-3 Trial of Bemnifosbuvir in High-Risk Outpatients with
COVID-19: Atea is continuing to enroll patients in the global, multicenter, randomized, double-blind, placebo-controlled, Phase 3 SUNRISE-3 trial evaluating
bemnifosbuvir or placebo administered concurrently with locally available standard of care (SOC). SUNRISE-3 is enrolling high-risk outpatients with mild or moderate
COVID-19, including those in the U.S., Europe and Japan. Patients are randomized 1:1 to receive bemnifosbuvir 550 mg twice-daily (BID) or placebo BID for five days.
The trial is comprised of two study populations based on the type of SOC received: 1) the “supportive care population,” evaluating bemnifosbuvir as
monotherapy (primary analysis), and 2) the “combination antiviral population,” assessing combination therapy if the SOC includes other compatible antiviral drugs against COVID-19 (secondary
analysis).
The primary endpoint of the SUNRISE-3 study is all-cause
hospitalization or death through Day 29 in the supportive care monotherapy cohort. The trial includes two interim analyses by the DSMB to assess safety and futility, conducted after approximately 650 and 1,350 evaluable patients, respectively, in
the supportive care monotherapy cohort have reached Day 29 post treatment. Atea reports that more than 1,400 patients have been enrolled in this cohort. As a result, both the first and second DSMB interim analyses are now planned. The Company
expects to report the outcome of each interim analysis following each meeting of the DSMB.
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