COVID-19-related hospitalization was defined as ≥ 24 hours of acute care for a reason related to COVID-19, in a hospital or similar acute care facility, including emergency rooms or temporary facilities instituted to address medical needs of those with COVID-19. This included specialized acute medical care units within an assisted living facility or nursing home. This did not include hospitalization for the purposes of public health and/or clinical trial execution. The date and duration of hospital admission, and primary reason for hospitalization (including if the hospitalization was related to COVID-19) were recorded. Percentages were rounded off.

The Full Analysis Positive Set included all randomized participants who received at least 1 dose of study drug and were SARS-CoV-2 positive at baseline as confirmed by cepheid's xpert xpress coronavirus-2/flu/respiratory syncytial virus plus test or SARS-CoV-2 reverse transcriptase quantitative polymerase chain reaction test from the central laboratory.

TEAEs were defined as 1 or both of the following:

Any AEs with an onset date on or after the study drug start date and no later than 30 days after permanent discontinuation of study drug. Any AEs leading to premature discontinuation of study drug. Percentages were rounded off.

The Safety Analysis Set included all participants who received at least 1 dose of study drug. One participant randomized to placebo arm received obeldesivir and was counted in obeldesivir group for the analysis of this outcome measure.

Treatment-emergent laboratory abnormalities were defined as values that increase at least 1 toxicity grade from baseline at any postbaseline time point, up to and including the date of last dose of study drug plus 30 days. Percentages were rounded off.

Participants from the Safety Analysis Set who had available post baseline data were analyzed. One participant randomized to placebo arm received obeldesivir and was counted in obeldesivir group for the analysis of this outcome measure.

A treatment emergent AE is defined as an AE that occurs or worsens in severity on or after the date of the first dose of study drug but no later than 30 days after the permanent discontinuation of study drug or an AE leading to discontinuation of study drug. A SAE is defined as an event that, at any dose, resulted in any of the following: death, life-threatening, in-patient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, a congenital anomaly/birth defect, or a medically important event or reaction. Percentages were rounded off.

Participants in the Safety Analysis Set were analyzed. One participant randomized to placebo arm received obeldesivir and was counted in obeldesivir group for the analysis of this outcome measure.

All-cause hospitalization was defined as ≥ 24 hours of acute care, in a hospital or similar acute care facility, including emergency rooms or temporary facilities instituted to address medical needs of those with COVID-19. This includes specialized acute medical care units within an assisted living facility or nursing home. This does not include hospitalization for the purposes of public health and/or clinical study execution. The date and duration of hospital admission, and primary reason for hospitalization (including if the hospitalization is related to COVID-19) were recorded. Percentages were rounded off.

Participants in the Full Analysis Positive Set were analyzed.

Medically attended visits were defined as interactions with health care professionals other than study staff or designees including hospitalization; in-person emergency, urgent, or primary care visits; or any other in-person visit attended by the participant and a health care professional. The nature and cause of the visit were identified. KM estimates were used in the outcome measure analysis. Percentages were rounded off.

Participants in the Full Analysis Positive Set were analyzed.

Medically attended visits were defined as interactions with health care professionals other than study staff or designees including hospitalization; in-person emergency, urgent, or primary care visits; or any other in-person visit attended by the participant and a health care professional. The nature and cause of the visit were identified. KM estimates were used in the outcome measure analysis. Percentages were rounded off.

Participants in the Full Analysis Positive Set were analyzed.

Percentages were rounded off.

Participants in the Full Analysis Positive Set were analyzed.

Time to COVID-19 symptom alleviation was calculated as symptom alleviation date/time minus the first dose date/time. Symptom alleviation was evaluated for the 15 targeted symptoms using symptoms of infection with coronavirus-19 (SIC) questionnaire. The SIC questionnaire assessed all targeted symptoms, alleviation was defined as the SIC rating of 0, or at least 3 points decrease in rating from baseline, or an answer "No" to the question for at least 48 consecutive hours.

Participants in the Full Analysis Positive Set with Covid19 symptoms who completed Symptoms of Infection With Coronavirus-19 at baseline were analyzed.

The mixed model for repeated measures (MMRM) was used for analysis.

Virology Analysis Set included all randomized participants who received at least 1 dose of study drug and had baseline SARS-CoV-2 viral load greater than or equal to lower limit of quantitation.

Pharmacokinetic Analysis Set included all randomized participants who received at least 1 dose of study drug and had at least 1 non missing concentration value reported by the PK laboratory with available data were analyzed .