for people ages 18 years and up (full criteria)
at Fresno, California and other locations
study started
completion around



Treatments are needed to improve outcomes among patients hospitalized for COVID-19, including direct-acting antiviral (DAA) agents to mitigate the pathology driven by ongoing viral replication. This trial will evaluate S-217622 (ensitrelvir), an anti-SARS-CoV2 3C-like protease inhibitor (PI) developed by Shionogi &; Co. Ltd.

The study design is a randomized, placebo-controlled, multi-center international clinical trial that will evaluate the clinical efficacy of ensitrelvir when given in addition to standard of care (SOC) for inpatients with COVID-19. The SOC will be determined by local established guidelines and may include additional DAA (e.g., remdesivir) and immunomodulatory treatment strategies. Certain SOC treatments will be pre-specified prior to randomization.

Official Title

Strategies and Treatments for Respiratory Infections & Viral Emergencies (STRIVE): Shionogi Protease Inhibitor


COVID-19, Respiratory Tract Infections, Emergencies, HIV Protease Inhibitors, Protease Inhibitors, Shionogi Protease Inhibitor (S-217622)


You can join if…

Open to people ages 18 years and up

  • Age ≥18 years.
  • Informed consent for trial participation.
  • Hospital admission (or boarding in an emergency department or other area awaiting hospital admission) with signs and/or symptoms of a respiratory infection.
  • Confirmation of SARS-CoV2 infection by nucleic acid test (NAT) or equivalent non- NAT test [list of approved tests is in the PIM] collected within the prior 14 days.
  • Onset of symptoms attributable to SARS-CoV2 infection occurred within 14 days before randomization.
  • Hospitalized for the management of COVID-19, with signs and/or symptoms suggestive of lower respiratory tract infection.

You CAN'T join if...

  • The patient is expected to be discharged from the hospital within the next 24 hours.
  • Medical condition other than the acute respiratory infection (and its manifestations) that is likely to result in death within 7 days of randomization.
  • Use of a strong CYP3A inducer within 14 days prior to enrollment
  • Moribund condition, defined as prior cardiac arrest during this hospitalization and life expectancy less than 48 hours of randomization.
  • Patient undergoing comfort care measures only such that treatment focuses on end-of- life symptom management over prolongation of life.
  • Expected inability or unwillingness to participate in study procedures.
  • In the opinion of the investigator, participation in a trial is not in the best interest of the patient.
  • Allergy to investigational agent or vehicle
  • Use of a concomitant medication that is contraindicated due to a drug-drug interaction with S-217622
  • Moderate to severe hepatic impairment (i.e., Child-Pugh class B or C) or acute liver failure.
  • Known estimated glomerular filtration rate (eGRF) <30 mL/min/1.73m 2
  • Continuous renal replacement therapy or chronic dialysis
  • Current pregnancy
  • Current breastfeeding and unwillingness to defer breastfeeding for 30 days after the last dose of investigational agent.
  • Women of child-bearing potential who are unwilling to abstain from sexual intercourse with men or practice appropriate contraception through 30 days from the last dose of the investigational agent.
  • Men who are unwilling to abstain from sexual intercourse with women of child- bearing potential or to use barrier contraception through 30 days from the last dose of the investigational agent.
  • Inability to take investigational agent in tablet form by mouth.


  • UCSF Fresno (Site 203-005) accepting new patients
    Fresno California 93721 United States
  • Zuckerberg San Francisco General Hospital and Trauma Center (Site 213-007) accepting new patients
    San Francisco California 94110 United States
  • UCSF Medical Center at Mount Zion (203-007) accepting new patients
    San Francisco California 94115 United States
  • UCSF (Site 203-001) accepting new patients
    San Francisco California 94143 United States
  • San Francisco VAMC (Site 074-002) accepting new patients
    San Francisco California 94121 United States
  • Veterans Affairs Palo Alto Health Care System (VAPAHCS) (Site 074-005) accepting new patients
    Palo Alto California 94304 United States
  • Stanford University Hospital & Clinics (Site 203-003) accepting new patients
    Stanford California 94305 United States


accepting new patients
Start Date
Completion Date
University of Minnesota
Phase 3 research study
Study Type
Expecting 1500 study participants
Last Updated