Paxlovid for Treatment of Long Covid

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• Post-Acute COVID-19 Syndrome 520

Post-Acute COVID-19 Syndrome

520 studies on the registry are indexed under Post-Acute COVID-19 Syndrome; 186 are open to participants now.

This study's enrollment of 168 is above the median of 60 across 361 interventional studies indexed under Post-Acute COVID-19 Syndrome.

Lead sponsor

Stanford University is the lead sponsor of 2,117 studies on the registry; 425 are open to participants now.

Of its 259 completed or terminated interventional studies of FDA-regulated products, 197 (76%) have results posted.

Study arms

• Experimental
  Nirmatrelvir plus ritonavir

  Participants receive nirmatrelvir plus ritonavir (Paxlovid) for 15 days, and attend follow-up visits through week 15.

  Drug: Nirmatrelvir · Drug: Ritonavir

• Placebo comparator
  Placebo plus ritonavir

  Participants receive placebo to match nirmatrelvir plus ritonavir for 15 days, and attend follow-up visits through week 15.

  Drug: Placebo · Drug: Ritonavir

Interventions

• DrugNirmatrelvir

  Two 150 mg tablets taken by mouth every 12 hours

• DrugPlacebo

  Two tablets containing placebo matching nirmatrelvir taken by mouth every 12 hours

• DrugRitonavir

  One 100 mg capsule taken by mouth every 12 hours

Primary outcomes

1. Number of Participants With No, Mild, Moderate, or Severe Symptoms at Week 10 According to the Core Symptoms Severity Scale Score

   This measure was to evaluate whether there is a difference between treatment with Paxlovid versus placebo on any of the 6 core symptoms of PASC at week 10 (adjusting for patients' baseline levels). Each symptom (fatigue, brain fog, dyspnea, body aches, gastrointestinal symptoms, cardiovascular symptoms) was assessed on a 4-point Likert scale (range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms).

   Time frame: Week 10

Secondary outcomes

1. Number of Participants With No, Mild, Moderate, or Severe Symptoms at Day 15 According to the Core Symptoms Severity Scale Score

   This measure was to evaluate whether there is a difference between treatment with Paxlovid versus placebo on any of the 6 core symptoms of PASC at week 10 (adjusting for patients' baseline levels). Each symptom (fatigue, brain fog, dyspnea, body aches, gastrointestinal symptoms, cardiovascular symptoms) was assessed on a 4-point Likert scale (range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms).

   Time frame: Day 15

2. Number of Participants Reporting Relief of at Least One Core Symptom for 2 Weeks

   Relief defined as reduction of severity from moderate to none, or severe to mild/none (≥ 2-point Likert score change). Likert score range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms.

   Time frame: Baseline through week 10, assessed at week 10

3. Number of Participants With Overall Alleviation for 2 Weeks

   Overall alleviation defined as both: 1. Any core symptom(s) that are none/mild (Likert 0 or 1) at baseline are none at 10 weeks, and 2. Any core symptom(s) that are moderate/severe (Likert 2 or 3) at baseline are none/mild at 10 weeks. Likert score range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms.

   Time frame: Baseline through week 10, assessed at week 10

4. Number of Participants With No, Mild, Moderate, or Severe Symptoms of Their Most Bothersome Symptom

   This outcome was to assess the severity of the most bothersome symptom experienced by participants. Each symptom was assessed on a 4-point Likert scale (range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms) using the Core Symptoms Severity Scale.

   Time frame: Assessed at weeks 5, 10, and 15

5. Time to Relief of the 6 Core Symptoms

   Relief defined as reduction of severity from moderate to none, or severe to mild/none for 2 consecutive weeks (≥ 2-point Likert score change). Likert score range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms.

   Time frame: Up to 15 weeks

6. Time to Relief of the Most Bothersome Symptom

   Relief defined as reduction of severity from moderate to none, or severe to mild/none for 2 consecutive weeks (≥ 2-point Likert score change). Likert score range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms.

   Time frame: Up to 15 weeks

7. Change in Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function T-Score

   The PROMIS-Physical Function Short Form (SF) assesses difficulty level performing activities of daily living such as doing chores, climbing stairs, walking, and running errands. The assessment consists of 4 items (questions) with each item scored on 5-point Likert scale (higher scores correspond to better physical function). Scores are computed to a T-score metric, where 50 represents the mean for US general adult population and 10 is the standard deviation. A higher physical function T-score indicates better physical function.

   Time frame: Baseline and week 10

8. Change in PROMIS Fatigue T-Score

   The PROMIS Fatigue Score assesses level of fatigue and its interference on daily activities. The assessment consists of 7 items (questions) with each item scored on 5-point Likert scale (higher scores correspond to more fatigue). Scores are computed to a T-score metric, where 50 represents the mean for US general adult population and 10 is the standard deviation. A higher fatigue T-score indicates greater fatigue.

   Time frame: Baseline and week 10

9. Change in PROMIS Dyspnea-Severity T-Score

   The PROMIS-Fatigue Dyspnea-Severity Short Form assesses shortness of breath and its interference on daily activities. The assessment consists of 5 items (questions) scored on 4-point Likert scale with a 7-day recall period (higher scores correspond to worse symptoms). Scores are computed to a T-score metric, where 50 represents the mean for US general adult population and 10 is the standard deviation. A higher Dyspnea-Severity T-score indicates worse symptoms.

   Time frame: Baseline and week 10

10. Change in PROMIS Cognitive Function Abilities T-Score

    The PROMIS-Cognitive Function Abilities Short Form assesses brain fog and its interference on daily activities. The assessment consists of 4 items scored on 5-point Likert scale with a 7-day recall period (higher scores indicate better cognitive function). Scores are computed to a T-score metric, where 50 represents the mean for US general adult population and 10 is the standard deviation. A higher Cognitive Function T-score indicates better cognitive function.

    Time frame: Baseline and week 10

11. Change in Orthostatic Vitals Test

    This outcome measures the difference in supine to standing systolic blood pressure (SBP) and diastolic blood pressure (DBP).

    Time frame: Baseline and week 10

12. Change in Heart Rate

    This outcome measures the difference in supine to standing heart rate.

    Time frame: Baseline and week 10

13. Change in 1-minute Sit-to-stand Test

    Number of times participant is able to go from sitting (in an armless chair) to standing in 1 minute (sit to stand cycles).

    Time frame: Baseline and week 10

14. Patient Global Impression of Severity (PGIS) Scale Score

    The PGIS reflects a participant's perception about the overall severity of their disease symptoms, rated from 1 to 6 (1 = not present; 2 = very mild; 3 = mild; 4 = moderate; 5 = severe; 6 = extremely severe).

    Time frame: Day 15, and weeks 5, 10, and 15

15. Patient Global Impression of Change (PGIC) Scale Score

    The PGIC reflects a participant's perception about the overall efficacy of treatment and their overall status since the start of the treatment, rated from 1 to 7 (1 = very much improved; 2 = much improved; 3 = minimally improved; 4 = no change; 5 = minimally worse; 6 = much worse; 7 = very much worse).

    Time frame: Day 15, and weeks 5, 10, and 15

16. Summative Severity Score for All Core Symptoms

    Core Symptoms Severity Scale Scores for each of the 6 core symptoms were summed to create a summative score. Each core symptom is assessed on a 4-point Likert scale (range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms). Summative score range: 0 to 18 (high scores correspond to greater severity).

    Time frame: Weeks 5, 10, and 15

17. Percentage of Weeks 1-15 With Mild or no Symptoms

    Each symptom (fatigue, brain fog, dyspnea, body aches, gastrointestinal symptoms, cardiovascular symptoms) is assessed on a 4-point Likert scale (range: 0 to 3; 0 = no symptoms; 1 = mild symptoms; 2 = moderate symptoms; 3 = severe symptoms).

    Time frame: 15 weeks

Baseline characteristics

8 further baseline measures are reported on the registry.

Publications

• Geng LN, Bonilla H, Hedlin H, Jacobson KB, Tian L, Jagannathan P, Yang PC, Subramanian AK, Liang JW, Shen S, Deng Y, Shaw BJ, Botzheim B, Desai M, Pathak D, Jazayeri Y, Thai D, O'Donnell A, Mohaptra S, Leang Z, Reynolds GZM, Brooks EF, Bhatt AS, Shafer RW, Miglis MG, Quach T, Tiwari A, Banerjee A, Lopez RN, De Jesus M, Charnas LR, Utz PJ, Singh U. Nirmatrelvir-Ritonavir and Symptoms in Adults With Postacute Sequelae of SARS-CoV-2 Infection: The STOP-PASC Randomized Clinical Trial. JAMA Intern Med. 2024 Sep 1;184(9):1024-1034. doi: 10.1001/jamainternmed.2024.2007. PubMed 38848477 ↗
• Gunturkun F, Hedlin H, Botzheim B, Deng Y, Bonilla H, Jagannathan P, Quach TC, Kim S, Lin M, O'Riordan G, Tzeng H, Adamowicz L, Demanuele C, Cai X, Yang PC, Singh U, Geng LN. Digital Biometric Measures in Long COVID: A Secondary Analysis of the STOP-PASC Randomized Clinical Trial. JAMA Netw Open. 2025 Aug 1;8(8):e2526901. doi: 10.1001/jamanetworkopen.2025.26901. PubMed 40810942 ↗

Study documents

• Protocol, analysis plan and consent form · May 5, 2023

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No — Currently, there is no plan for data sharing.