NCT06161688

Ensitrelvir for Viral Persistence and Inflammation in People Experiencing Long COVID

Placebo-Controlled, Randomized Trial of Ensitrelvir (S-217622) for Viral Persistence and Inflammation in People Experiencing Long COVID (PREVAIL-LC)

• Status: Active Not Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 40 (actual)
• Sponsor: Timothy Henrich · Academic / Other
• Sex: All
• Age: 18 Years – 69 Years
• Healthy volunteers: Not accepted

Summary

Persistent viral infection with viral reservoirs and detection of circulating spike protein after the initial acute illness is one potential pathogenic mechanism for Long COVID. This mechanism may be susceptible to antiviral therapy that blocks viral replication, which has the potential to alleviate long COVID symptoms. This trial will study the safety and efficacy of Ensitrelvir (S-217622), an antiviral, to treat individuals with Long COVID in an adult population.

Detailed description

The study will enroll approximately 40 participants who meet the World Health Organization (WHO) Long COVID criteria. Participants will be enrolled at a single center and randomized 1:1 to receive ensitrelvir fumaric acid (Ensitrelvir: S-217622), given orally for 5 days, or placebo. Subjects randomized to receive Ensitrelvir will take 375 mg on day 1, followed by 125 mg daily for 4 additional days. Evaluations will take place at baseline and at timepoints up to 60 days post-initiation of study drug.

Conditions

• Long COVID
• Post Acute Sequelae of COVID-19
• Post-Acute COVID-19

Interventions

Type	Name	Description
DRUG	Ensitrelvir	Those randomized to the experimental arm will receive Ensitrelvir, a protease inhibitor, taken orally for 5 days
OTHER	Placebo	Matching placebo for Ensitrelvir

Timeline

• Start date: 2024-04-09
• Primary completion: 2024-12-20
• Completion: 2026-12-31
• First posted: 2023-12-08
• Last updated: 2026-04-02
• Results posted: 2026-04-02

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study