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Bemnifosbuvir

Phase 3

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV 2 Infection) | Small molecule | Infectious Disease |Atea Pharmaceuticals, Inc.|Last Updated: Oct 21, 2025

Success Probability

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Market & Valuation

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Trial Design

RandomizedDouble-BlindPLACEBO_CONTROLLEDDMC
Total Trials1
Total Enrollment2,285

FDA Designations

FAST_TRACK

Clinical trial landscape

Bemnifosbuvir · 5 trials · 10 indications

Phase 3 1Phase 2 1Phase 1 3
NCT05629962SUNRISE-3: Efficacy and Safety of Bemnifosbuvir in High-Risk Outpatients With COVID-19Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV 2 Infection)
COMPLETED2,285 Analytics
PHASE3COMPLETED
SUNRISE-3: Efficacy and Safety of Bemnifosbuvir in High-Risk Outpatients With COVID-19
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV 2 Infection)Unlock trial analytics

Study Endpoints

Primary Endpoints

Percentage of Subjects Hospitalized for Any Cause or Died Due to Any Cause
Day 1 through Day 29
Percentage of Subjects Achieving Sustained Virologic Response at 12 Weeks Post-treatment (SVR12)
Day 1 through 12 weeks after end of treatment

SVR12 defined as plasma hepatitis C virus (HCV) RNA less than the lower limit of quantitation (\<LLOQ) at 12 weeks post-treatment

Pharmacokinetics (PK) of BEM Maximum plasma concentration (Cmax)
Day 1, Day 5
Pharmacokinetics (PK) of BEM Area under the plasma concentration-time curve (AUC)
Day 1, Day 5
Placebo-corrected (Δ) change-from-baseline QTc (ΔΔQTc).
24 hours prior to dosing thru 48 hours post dose

C-QTc analysis

Pharmacokinetics (PK) of BEM AUC
Day 1

Secondary Endpoints

Percentage of Subjects Hospitalized Due to COVID-19 or Died Due to Any Cause
Day 1 through Day 29
Percentage of Subjects Who Died Due to Any Cause
Day 1 through Day 29; Day 1 through Day 60
Percentage of Subjects With COVID-19-related Complications
Day 1 through Day 29
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Study Design & Arms

AllocationRANDOMIZED
MaskingTRIPLE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
Bemnifosbuvir (BEM)EXPERIMENTAL -
PlaceboPLACEBO_COMPARATOR -
Bemnifosbuvir and RuzasvirEXPERIMENTALBemnifosbuvir (BEM; AT-527) Tablets Ruzasvir (RZR; AT-038) Capsules
Bemnifosbuvir (BEM) therapeutic doseEXPERIMENTALoral tablets
Bemnifosbuvir (BEM) supratherapeutic doseEXPERIMENTALoral tablets
MoxifloxacinACTIVE_COMPARATORoral tablet
Group 1 -Mild Hepatic ImpairmentEXPERIMENTALDrug: single dose Bemnifosbuvir (BEM)
Group 2-Moderate Hepatic ImpairmentEXPERIMENTALDrug: single dose Bemnifosbuvir (BEM)
Group 3 - Healthy Subjects matching mild and moderate impairment groupsEXPERIMENTALDrug: single dose Bemnifosbuvir (BEM)
Group 4 - Severe Hepatic ImpairmentEXPERIMENTALDrug: single dose Bemnifosbuvir (BEM)
Group 5 - Normal hepatic function matching severe impairment groupEXPERIMENTALDrug: single dose Bemnifosbuvir (BEM)

Interventions

NameTypeDescription
Bemnifosbuvir (BEM)DRUGBEM tablets administered orally every 12 hours (twice a day) for a total of 5 days
PlaceboDRUGPlacebo tablets administered orally every 12 hours (twice a day) for a total of 5 days
BemnifosbuvirDRUG550 mg administered orally once a day (QD) for 8 weeks
RuzasvirDRUG180 mg administered orally once a day (QD) for 8 weeks
MoxifloxacinDRUGA single dose of Moxifloxacin will be administered.
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Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites263

Inclusion Criteria: * Positive SARS-CoV-2 test conducted ≤ 5 days prior to randomization * Mild or moderate COVID-19 with symptom onset ≤ 5 days before randomization and at least one COVID-19 related symptom present at time of screening * Subject must be high risk, defined below: 1. Age ≥70 year...

Countries:United StatesArgentinaBrazilCanadaGermanyIndiaJapanLatviaMexicoNetherlandsPakistanPhilippinesRomaniaSouth AfricaSpainSwedenTunisiaTurkey (Türkiye)United KingdomMauritiusMoldovaSouth Korea
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Frequently asked questions about Bemnifosbuvir

What is Bemnifosbuvir used for?

Bemnifosbuvir is an investigational small molecule being studied for the treatment of chronic Hepatitis C virus infection and for SARS-CoV-2 infection (COVID-19). It has been evaluated in clinical trials for these infectious disease indications, though it is not yet approved and remains in clinical development.

What does Bemnifosbuvir target?

Bemnifosbuvir is a small molecule antiviral that targets viral RNA polymerase, an enzyme essential for viral replication. By inhibiting this polymerase, the drug aims to block the replication of viruses such as SARS-CoV-2 and Hepatitis C virus, thereby reducing viral load in infected patients.

Who makes Bemnifosbuvir?

Bemnifosbuvir is being developed by Atea Pharmaceuticals, Inc., a biopharmaceutical company traded on the NASDAQ under the ticker symbol AVIR. The company is conducting clinical trials to evaluate the drug's safety and efficacy for treating viral infections, including COVID-19 and chronic Hepatitis C.

What phase is Bemnifosbuvir in?

Bemnifosbuvir has completed Phase 1, Phase 2, and Phase 3 clinical trials. A Phase 3 trial for COVID-19 and a Phase 2 trial for chronic Hepatitis C have both been completed. The drug has received Fast Track designation from the FDA, but it is not yet approved and remains investigational.

What clinical trials is Bemnifosbuvir in?

Bemnifosbuvir has been studied in several completed trials, including NCT05629962 (SUNRISE-3, a Phase 3 trial in high-risk outpatients with COVID-19), NCT05904470 (a Phase 2 trial in chronic Hepatitis C), and two Phase 1 trials in healthy volunteers (NCT05905484 and NCT05905497).

Is Bemnifosbuvir the same as Ruzasvir?

No, Bemnifosbuvir is not the same as Ruzasvir. They are separate investigational drugs that have been studied in combination for the treatment of chronic Hepatitis C. In a Phase 2 clinical trial, Bemnifosbuvir was administered together with Ruzasvir to evaluate their combined safety and efficacy in patients with chronic HCV.