Alleviation of COVID-19 Symptoms and Reduction in Healthcare Utilization Among High-Risk Patients Treated With Nirmatrelvir/Ritonavir (NMV/R): A phase 3 randomized trial.

Background: Nirmatrelvir/ritonavir (NMV/r) is an oral antiviral treatment for mild to moderate COVID-19.

Methods: This phase 2/3, double-blind, randomized (1:1) study assessed oral NMV/r 300 mg/100 mg versus placebo every 12 hours for 5 days in high-risk, unvaccinated, nonhospitalized, symptomatic adults with COVID-19 from 343 sites across 21 countries. In testing the primary endpoint of COVID-19‒related hospitalization and all-cause deaths and key secondary endpoints including symptom duration and COVID-19‒related medical visits, Type I error was controlled with prespecified sequential testing and the Hochberg procedure.

Oral Nirmatrelvir-Ritonavir as Postexposure Prophylaxis for Covid-19.

Background: Clinical trials of treatments for coronavirus disease 2019 (Covid-19) have not shown a significant benefit of postexposure prophylaxis.

Methods: We conducted a phase 2-3 double-blind trial to assess the efficacy and safety of nirmatrelvir-ritonavir in asymptomatic, rapid antigen test-negative adults who had been exposed to a household contact with Covid-19 within 96 hours before randomization. The participants were randomly assigned in a 1:1:1 ratio to receive nirmatrelvir-ritonavir (300 mg of nirmatrelvir and 100 mg of ritonavir) every 12 hours for 5 days or for 10 days or matching placebo for 5 or 10 days.

Nirmatrelvir for Vaccinated or Unvaccinated Adult Outpatients with Covid-19.

Background: Nirmatrelvir in combination with ritonavir is an antiviral treatment for mild-to-moderate coronavirus disease 2019 (Covid-19). The efficacy of this treatment in patients who are at standard risk for severe Covid-19 or who are fully vaccinated and have at least one risk factor for severe Covid-19 has not been established.

Methods: In this phase 2-3 trial, we randomly assigned adults who had confirmed Covid-19 with symptom onset within the past 5 days in a 1:1 ratio to receive nirmatrelvir-ritonavir or placebo every 12 hours for 5 days.

Oral Nirmatrelvir for High-Risk, Nonhospitalized Adults with Covid-19.

Background: Nirmatrelvir is an orally administered severe acute respiratory syndrome coronavirus 2 main protease (M) inhibitor with potent pan-human-coronavirus activity in vitro.

Methods: We conducted a phase 2-3 double-blind, randomized, controlled trial in which symptomatic, unvaccinated, nonhospitalized adults at high risk for progression to severe coronavirus disease 2019 (Covid-19) were assigned in a 1:1 ratio to receive either 300 mg of nirmatrelvir plus 100 mg of ritonavir (a pharmacokinetic enhancer) or placebo every 12 hours for 5 days. Covid-19-related hospitalization or death from any cause through day 28, viral load, and safety were evaluated.

Strengthening the interpretability of clinical trial results by assessing the effect of informative censoring on the primary estimand in PRECISION.

Background: The ICH E9(R1) addendum states that the strategy to account for intercurrent events should be included when defining an estimand, the treatment effect to be estimated based on the study objective. The estimator used to assess the treatment effect needs to be aligned with the estimand that accounted for intercurrent events. Regardless of the strategy, missing data resulting from patient premature withdrawal could undermine the robustness of the study results.