Nirmatrelvir/Ritonavir Regimen for Mild/Moderately Severe COVID-19: A Rapid Review With Meta-Analysis and Trial Sequential Analysis

Ann Fam Med. 2024 Jul-Aug;22(4):336-346. doi: 10.1370/afm.3120.

Abstract

Background: The efficacy, effectiveness, and safety of the approved nirmatrelvir/ritonavir regimen for treatment of laboratory-confirmed mild/moderately severe COVID-19 remains unclear.

Methods: We systematically identified randomized controlled trials (RCTs) and real-world studies (RWS; observational studies) of the efficacy/effectiveness and/or safety of the approved nirmatrelvir/ritonavir regimen for COVID-19. We pooled appropriate data (adjusted estimates for RWS) using an inverse variance, random-effects model. We calculated statistical heterogeneity using the I 2 statistic. Results are presented as relative risk (RR) with associated 95% CI. We further assessed risk of bias/study quality and conducted trial sequential analysis of the evidence from RCTs.

Results: We included 4 RCTs (4,070 persons) and 16 RWS (1,925,047 persons) of adults (aged ≥18 years). One and 3 RCTs were of low and unclear risk of bias, respectively. The RWS were of good quality. Nirmatrelvir/ritonavir significantly decreased COVID-19 hospitalization compared with placebo/no treatment (RR = 0.17; 95% CI, 0.10-0.31; I 2 = 77.2%; 2 RCTs, 3,542 persons), but there was no significant difference for decrease of worsening severity (RR = 0.82; 95% CI, 0.66-1.01; I 2 = 47.5%; 3 RCTs, 1,824 persons), viral clearance (RR = 1.19; 95% CI, 0.93-1.51; I 2 = 82%; 2 RCTs, 528 persons), adverse events (RR = 1.41; 95% CI, 0.92-2.14; I 2 = 70.6%; 4 RCTs, 4,070 persons), serious adverse events (RR = 0.82; 95% CI, 0.41-1.62; I 2 = 0%; 3 RCTs, 3,806 persons), and all-cause mortality (RR = 0.27; 95% CI, 0.04-1.70; I 2 = 49.9%; 3 RCTs, 3,806 persons), although trial sequential analysis suggested that the current total sample sizes for these outcomes were not large enough for conclusions to be drawn. Real-world studies also showed significantly decreased COVID-19 hospitalization (RR = 0.48; 95% CI, 0.37-0.60; I 2 = 95.0%; 11 RWS, 1,421,398 persons) and all-cause mortality (RR = 0.24; 95% CI, 0.14-0.34; I 2 = 65%; 7 RWS, 286,131 persons) for nirmatrelvir/ritonavir compared with no treatment.

Conclusions: Nirmatrelvir/ritonavir appears to be promising for preventing hospitalization and potentially decreasing all-cause mortality for persons with mild/moderately severe COVID-19, but the evidence is weak. More studies are needed.

Keywords: Paxlovid; efficacy/effectiveness; laboratory-confirmed COVID-19; nirmatrelvir/ritonavir; quantitative methods: meta-analysis; safety; systematic review; trial sequential analysis.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Antiviral Agents / therapeutic use
  • COVID-19 / mortality
  • COVID-19 Drug Treatment*
  • Drug Therapy, Combination
  • Humans
  • Indazoles / therapeutic use
  • Randomized Controlled Trials as Topic
  • Ritonavir* / therapeutic use
  • SARS-CoV-2*
  • Severity of Illness Index

Substances

  • Ritonavir
  • Antiviral Agents
  • Indazoles