RecruitingPhase 3Drug trialA Study to Learn About the Study Medicine Ibuzatrelvir in Adults With COVID-19 Who Are Severely ImmunocompromisedThis is a Phase 3, randomized, actively controlled, double-blinded, double-dummy, superiority study to evaluate the efficacy and safety of ibuzatrelvir alone and in combination with remdesivir IV compared to remdesivir IV alone for the treatment of symptomatic COVID-19 in severely immunocompromised adult participants who are non-hospitalized or are hospitalized for observation or study intervention administration but do not require supplemental oxygen for COVID-19.