A Phase 2 interventional study of Bemnifosbuvir and Ruzasvir in Chronic Hepatitis C Virus, Hepatitis C, Chronic and Hepatitis C, sponsored by Atea Pharmaceuticals, Inc.. Completed at 51 sites in 12 countries. Open to participants aged 18 Years to 85 Years. Per ClinicalTrials.gov, last updated 2025-10-21.
Sponsored by Atea Pharmaceuticals, Inc. · Phase 2, Interventional, and Treatment
This is an open-label trial to evaluate safety and efficacy of treatment with BEM + RZR in subjects with chronic HCV infection.
950 studies on the registry are indexed under Hepatitis C, Chronic; 8 are open to participants now.
This study's enrollment of 275 is above the median of 90 across 696 interventional studies indexed under Hepatitis C, Chronic.
Browse Hepatitis C, Chronic studies →Atea Pharmaceuticals, Inc. is the lead sponsor of 33 studies on the registry; 1 is open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 4 (16%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Liver disease staging assessment as follows:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Child-Pugh class
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bemnifosbuvir (BEM; AT-527) Tablets Ruzasvir (RZR; AT-038) Capsules
Drug: Bemnifosbuvir · Drug: Ruzasvir
550 mg administered orally once a day (QD) for 8 weeks
Also known as: AT-527
180 mg administered orally once a day (QD) for 8 weeks
Also known as: AT-038
Percentage of Subjects Achieving Sustained Virologic Response at 12 Weeks Post-treatment (SVR12)
SVR12 defined as plasma hepatitis C virus (HCV) RNA less than the lower limit of quantitation (\<LLOQ) at 12 weeks post-treatment
Time frame: Day 1 through 12 weeks after end of treatment
Percentage of Subjects Experiencing Virologic Failure
Virologic failure defined as a confirmed 1 log10 increase in HCV RNA from post-baseline nadir, or confirmed increase in HCV RNA ≥ LLOQ in any subject who achieved HCV RNA \< LLOQ.
Time frame: Day 1 through 12 weeks after end of treatment
Percentage of Subjects Achieving Sustained Virologic Response at 24 Weeks Post-treatment (SVR24)
SVR24 defined as plasma HCV RNA less than the lower limit of quantitation (\<LLOQ) at 24 weeks post-treatment
Time frame: Day 1 through 24 weeks after end of treatment
| Milestone | BEM+RZR |
|---|---|
| Started | 275 |
| Completed | 255 |
| Not completed | 20 |
SVR12 defined as plasma hepatitis C virus (HCV) RNA less than the lower limit of quantitation (\<LLOQ) at 12 weeks post-treatment
| Participants | BEM+RZR |
|---|---|
| Percentage of Subjects Achieving Sustained Virologic Response at 12 Weeks Post-treatment (SVR12) | 210 |
Virologic failure defined as a confirmed 1 log10 increase in HCV RNA from post-baseline nadir, or confirmed increase in HCV RNA ≥ LLOQ in any subject who achieved HCV RNA \< LLOQ.
| Participants | BEM+RZR |
|---|---|
| Percentage of Subjects Experiencing Virologic Failure | 5 |
SVR24 defined as plasma HCV RNA less than the lower limit of quantitation (\<LLOQ) at 24 weeks post-treatment
| Participants | BEM+RZR |
|---|---|
| Percentage of Subjects Achieving Sustained Virologic Response at 24 Weeks Post-treatment (SVR24) | 206 |
Collected over Treatment-emergent adverse events were collected through 4 weeks post-treatment and serious adverse events were collected through 24 weeks post-treatment.. Non-serious events are listed at a 2% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| BEM+RZR | 5/275 (1.8%) | 19/275 (6.9%) | 64/275 (23.3%) |
| Event | BEM+RZR |
|---|---|
| OverdoseInjury, poisoning and procedural complications | 3/275 |
| OsteoarthritisMusculoskeletal and connective tissue disorders | 2/275 |
| Atrioventricular block completeCardiac disorders | 1/275 |
| PyrexiaGeneral disorders | 1/275 |
| Abscess limbInfections and infestations | 1/275 |
| Dengue feverInfections and infestations | 1/275 |
| Oesophageal squamous cell carcinomaNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 1/275 |
| Behaviour disorderPsychiatric disorders | 1/275 |
| Substance-induced psychotic disorderPsychiatric disorders | 1/275 |
| Urinary tract obstructionRenal and urinary disorders | 1/275 |
| Event | BEM+RZR |
|---|---|
| HeadacheNervous system disorders | 24/275 |
| NauseaGastrointestinal disorders | 22/275 |
| DyspepsiaGastrointestinal disorders | 12/275 |
| VomitingGastrointestinal disorders | 12/275 |
| PyrexiaGeneral disorders | 11/275 |
| DiarrhoeaGastrointestinal disorders | 10/275 |
| FatigueGeneral disorders | 7/275 |
| Abdominal pain upperGastrointestinal disorders | 6/275 |
| Age, Continuous(years) | BEM+RZR |
|---|---|
| Mean | 49.6 ± 13.02 |
| Sex: Female, Male(Participants) | BEM+RZR |
|---|---|
| Female | 131 |
| Male | 144 |
| Race (NIH/OMB)(Participants) | BEM+RZR |
|---|---|
| American Indian or Alaska Native | 1 |
| Asian | 55 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 11 |
| White | 192 |
| More than one race | 3 |
| Unknown or Not Reported | 13 |
| Genotype (GT)(Participants) | BEM+RZR |
|---|---|
| GT1 | 189 |
| GT2 | 7 |
| GT3 | 77 |
| GT4 | 2 |
| Compensated Cirrhosis(Participants) | BEM+RZR |
|---|---|
| Count of participants | 37 |
PDFs hosted by the registry, ClinicalTrials.gov.
This study is completed, as verified in Oct 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Bemnifosbuvir · Ruzasvir