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Bemnifosbuvir (BEM)
Bemnifosbuvir (BEM) is a Nucleoside analog; viral polymerase inhibitor Small molecule drug developed by Atea Pharmaceuticals, Inc.. It is currently in Phase 3 development for COVID-19 (SARS-CoV-2 infection), Respiratory viral infections. Also known as: AT-527.
Bemnifosbuvir is a nucleoside analog that inhibits viral RNA-dependent RNA polymerase, blocking replication of RNA viruses.
Bemnifosbuvir (BEM) is a small molecule with an unknown mechanism of action, as its specific mechanism is not provided in the given facts. It is being studied in a Phase 1 clinical trial to evaluate its interaction with buprenorphine/naloxone or methadone in healthy volunteers.
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Baseline phase 3 → approval rate
+58.3pp
Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas). -
Anti-infectives pathway favourability
+2.0pp
Microbiological endpoints + non-inferiority designs raise approval rates above baseline.
| Regulator | Country | Likely year | Lag vs FDA |
|---|---|---|---|
| FDA | US | 2028–2030 | — |
| EMA | EU | 2029–2031 | +0.7 yr |
| MHRA | GB | 2029–2031 | +0.7 yr |
| Health Canada | CA | 2029–2032 | +0.9 yr |
| TGA | AU | 2029–2032 | +1.2 yr |
| PMDA | JP | 2029–2032 | +1.5 yr |
| NMPA | CN | 2030–2033 | +2.3 yr |
| MFDS | KR | 2029–2032 | +1.4 yr |
| CDSCO | IN | 2029–2033 | +1.8 yr |
| ANVISA | BR | 2030–2033 | +2.3 yr |
Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).
Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.
At a glance
| Generic name | Bemnifosbuvir (BEM) |
|---|---|
| Also known as | AT-527 |
| Sponsor | Atea Pharmaceuticals, Inc. |
| Drug class | Nucleoside analog; viral polymerase inhibitor |
| Target | Viral RNA-dependent RNA polymerase (RdRp) |
| Modality | Small molecule |
| Therapeutic area | Virology; Infectious Disease |
| Phase | Phase 3 |
Mechanism of action
Bemnifosbuvir is a phosphoramidate prodrug of a nucleoside analog that targets the RNA-dependent RNA polymerase (RdRp) of RNA viruses. Upon cellular uptake and metabolic activation, it is incorporated into the viral RNA chain during replication, causing chain termination and preventing viral genome synthesis. This mechanism has broad-spectrum activity against multiple RNA viruses including respiratory viruses.
Approved indications
- COVID-19 (SARS-CoV-2 infection)
- Respiratory viral infections
Common side effects
- Nausea
- Diarrhea
- Headache
- Fatigue
Key clinical trials
- C-Forward: Efficacy and Safety of BEM/RZR vs SOF/VEL in Subjects With Chronic HCV (PHASE3)
- Drug-drug Interaction Study of Bemnifosbuvir/Ruzasvir (BEM/RZR) and Buprenorphine/Naloxone or Methadone (PHASE1)
- Drug-drug Interaction Study of Bemnifosbuvir/Ruzasvir (BEM/RZR) and Ethinyl Estradiol/Levonorgestrel (EE/LNG) (PHASE1)
- C-BEYOND: Efficacy and Safety of BEM/RZR vs. SOF/VEL in Subjects With Chronic HCV (PHASE3)
- A Phase 2, Safety and Efficacy of Bemnifosbuvir (BEM) and Ruzasvir (RZR) in Subjects With Chronic HCV (PHASE2)
- Study of Bemnifosbuvir/Ruzasvir as a Fixed-dose Combination in Subjects With Normal or Severely Impaired Renal or Hepatic Function (PHASE1)
- Drug-drug Interaction Study of Omeprazole and Bemnifosbuvir/Ruzasvir (PHASE1)
- Drug-drug Interaction Study of Bemnifosbuvir/Ruzasvir (BEM/RZR) and Digoxin and Rosuvastatin (PHASE1)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Bemnifosbuvir (BEM) CI brief — competitive landscape report
- Bemnifosbuvir (BEM) updates RSS · CI watch RSS
- Atea Pharmaceuticals, Inc. portfolio CI
Frequently asked questions about Bemnifosbuvir (BEM)
What is Bemnifosbuvir (BEM)?
How does Bemnifosbuvir (BEM) work?
What is Bemnifosbuvir (BEM) used for?
Who makes Bemnifosbuvir (BEM)?
Is Bemnifosbuvir (BEM) also known as anything else?
What drug class is Bemnifosbuvir (BEM) in?
What development phase is Bemnifosbuvir (BEM) in?
What are the side effects of Bemnifosbuvir (BEM)?
What does Bemnifosbuvir (BEM) target?
Related
- Drug class: All Nucleoside analog; viral polymerase inhibitor drugs
- Target: All drugs targeting Viral RNA-dependent RNA polymerase (RdRp)
- Manufacturer: Atea Pharmaceuticals, Inc. — full pipeline
- Therapeutic area: All drugs in Virology; Infectious Disease
- Indication: Drugs for COVID-19 (SARS-CoV-2 infection)
- Indication: Drugs for Respiratory viral infections
- Also known as: AT-527
Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing