Who is sponsoring STOP-PASC?

STOP-PASC is sponsored by Stanford University.

What condition does STOP-PASC study?

STOP-PASC studies Post-acute Sequelae of SARS-CoV-2 Infection, Long COVID.

What drugs are being tested in STOP-PASC?

Interventions: Nirmatrelvir, Placebo, Ritonavir.

What is the status of STOP-PASC?

STOP-PASC is currently COMPLETED.

Last reviewed 2025-09-04 · How we verify

Paxlovid for Treatment of Long Covid (STOP-PASC)

NCT05576662 PHASE2 COMPLETED Results posted

The purpose of this study is to compare whether being treated with nirmatrelvir plus ritonavir for 15 days works better than being treated with placebo plus ritonavir to reduce severe symptoms of Long Covid. Participants will have 5 planned visits to the study clinic over 15 weeks and will take the drug (or placebo) for the first 15 days. This study uses the term post-acute sequelae of SARS-CoV-2 (PASC), which is another name for "Long Covid."

Details

Lead sponsor	Stanford University
Phase	PHASE2
Status	COMPLETED
Enrolment	168
Start date	Tue Nov 08 2022 00:00:00 GMT+0000 (Coordinated Universal Time)
Completion	Tue Sep 12 2023 00:00:00 GMT+0000 (Coordinated Universal Time)

Conditions

Post-acute Sequelae of SARS-CoV-2 Infection
Long COVID

Interventions

Nirmatrelvir
Placebo
Ritonavir

Countries

United States