A Phase III study to evaluate the Efficacy, Safety, and Antiviral Activity of RO7496998 (AT-527) in Non-hospitalized Patients with Mild or Moderate COVID-19

A Multicenter, Phase III Randomized, Double-blind, Placebo-Controlled, Outpatient study to Evaluate the Efficacy, Safety, and Antiviral Activity of RO7496998 AT-527 in Patients With Mild or Moderate COVID-19

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2031210070

Enrollment

1386

Registered

2021-05-07

Start date

2021-06-16

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

SARS-COV-2 infection

Interventions

RO7496998 (AT-527): 550mg twice daily for 5days

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: - Age >=18 years (regardless of weight) or age >=12 to =40 kg ) at the time of signing informed consent (and assent) - At least three of the following symptoms of at least moderate (score >=2 as per COVID-19 Symptom Diary) intensity: nasal congestion or runny nose, sore throat, cough, shortness of breath, muscle or body aches, fatigue, headache, chills or sweats, feeling hot or feverish, nausea, vomiting, or diarrhea - Positive SARS-CoV-2 diagnostic test withoin72 hours prior to randomization - Symptoms consistent with mild or moderate COVID-19 with onset within 5 days before randomization - For women of childbearing potential: agreement to remain abstinent or use adequate contraception during the study duration

Exclusion criteria

Exclusion criteria: - Admitted to a hospital prior to randomization at randomization due to COVID-19 - Is likely to experience imminent deterioration and require hospitalization - Treatment with an investigational drug within 5 half-lives or 30 days (whichever is longer) of randomization - Treatment with a COVID-19 therapeutic agent against SARS-CoV-2 within the last 2 weeks prior to the screening visit - Concomitant use of P-glycoprotein inhibitors or inducers - Abnormal laboratory test results at screening

Design outcomes

Primary

Measure	Time frame
Efficacy The time to alleviation or improvement of COVID-19 symptoms (Items 1-12 of the COVID-19 symptom diary) maintained for a duration of 21.5 hours	—

Secondary

Measure	Time frame
Efficacy, Safety, Phamacokinetics, Phamacodynamics, Phamacogenomics 1.Efficacy -Time to alleviation of COVID-19 symptoms -Proportion of patients requiring hospitalization for COVID-19 -Proportion of patients with >= 1 COVID-19 related medically attended visit through to study end -Duration of fever -Frequency of COVID-19 related complications -Proportion of patients with any post-treatment infection -Proportion of patients with all-cause mortality -Change from baseline in amount of SARS-CoV-2 virus RNA, as measured by RT-qPCR at each timepoint 2.Safety -Adverse events, Vital signs, Clinical laboratory test results 3.Phamacodynamics -Plasma concentration of AT-511 (the free base form of RO7496998 [AT-527]), AT-551, AT-229, and AT-273 (a surrogate for the intracellular concentration of the active triphosphate metabolite AT-9010) at specified timepoints	—

Measure

Time frame

Efficacy, Safety, Phamacokinetics, Phamacodynamics, Phamacogenomics 1.Efficacy -Time to alleviation of COVID-19 symptoms -Proportion of patients requiring hospitalization for COVID-19 -Proportion of patients with >= 1 COVID-19 related medically attended visit through to study end -Duration of fever -Frequency of COVID-19 related complications -Proportion of patients with any post-treatment infection -Proportion of patients with all-cause mortality -Change from baseline in amount of SARS-CoV-2 virus RNA, as measured by RT-qPCR at each timepoint 2.Safety -Adverse events, Vital signs, Clinical laboratory test results 3.Phamacodynamics -Plasma concentration of AT-511 (the free base form of RO7496998 [AT-527]), AT-551, AT-229, and AT-273 (a surrogate for the intracellular concentration of the active triphosphate metabolite AT-9010) at specified timepoints

—

Countries

Argentina, Belgium, Brazil, Columbia, Denmark, France, Germany, Hungary, Italy, Japan, Mexico, Peru, Poland, Russia, Serbia, Spain, Switzerland, Turkey, Ukraine, United States

Contacts

Public ContactClinical trials information

Chugai Pharmaceutical Co., Ltd.

clinical-trials@chugai-pharm.co.jp+81-120-189-706

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026