Phase 3 Study of S-217622 in Prevention of Symptomatic SARS-CoV-2 Infection
Summary
The purpose of this study is to measure the proportion of participants who are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (positive reverse transcription polymerase chain reaction \[RT-PCR\] test) and have coronavirus disease 2019 (COVID-19) symptom(s) with S-217622 tablets compared with placebo tablets in participants who are household contacts of an individual with symptomatic COVID-19.
Timeline
- Start
- 2023-06-09
- Primary completion
- 2024-08-30
- Completion
- 2024-09-18
Outcome
Met primary endpoint
paper The incidence of Covid-19 was lower in the ensitrelvir group than in the placebo group (2.9% vs. 9.0%; risk ratio, 0.33; PMID 42127390 ↗
paper P<0.001). PMID 42127390 ↗
paper Ensitrelvir administered to household contacts of a patient with Covid-19 within 72 hours after symptom onset in the index patient was effective PMID 42127390 ↗
release “study, Stopping COVID-19 pRogression with early Protease InhibitOr treatment – Post Exposure Prophylaxis (SCORPIO-PEP), met its primary endpoint.” shionogi.com ↗
release “SCORPIO-PEP) assessing ensitrelvir as oral post-exposure prophylaxis met the primary endpoint of preventing COVID-19.” shionogi.com ↗
Publications
- Hayden FG, Shinkai M, Clark TW, Luetkemeyer AF, Sax PE, Hanage WP, Gebo KA, Ikematsu H, Izumikawa K, Fukushi A, Kezbor S, Sakaguchi H, Lacey S, Ichihashi G, Ohmagari N, Uehara T; SCORPIO-PEP Study Team. Ensitrelvir for Covid-19 Postexposure Prophylaxis in Household Contacts. N Engl J Med. 2026 May 14;394(19):1905-1915. doi: 10.1056/NEJMoa2509306.
- Toselli F, Jacobs S, Scheers E, Jacobs T, Doijen J, Hereijgers J, Keustermans K, Aerts L, van Heerden M, Van Loock M, Mason S, Monshouwer M, Van Damme E, Herschke F. Optimal preclinical models for human dose projection of SARS-CoV-2 small molecule direct-acting antivirals. Antiviral Res. 2026 Apr;248:106363. doi: 10.1016/j.antiviral.2026.106363. Epub 2026 Feb 9.
Drugs
| Evaluation | Drug | Modality | Dose | Route |
|---|---|---|---|---|
| Subject | Ensitrelvir | Small molecule | 125 mg | Oral |