The antiviral did not modify SARS–CoV-2 RNA clearance, and did not increase the risk of adverse events.
The antiviral, Nirmatrelvir plus ritonavir (Paxlovid), has been indicated to treat COVID-19 patients in the early onset of disease and not when cases has progressed in severity or hospitalization.
In mild and moderate cases, the antiviral has been shown to reduce the risk of hospitalization or death by 89% in high-risk, ambulatory adults with COVID-19.
In a new study, investigators wanted to see if there was therapeutic benefit to using Paxlovid to treat hospitalized patients with the Omicron variant.
The new study published in The Lancet examined patients hospitalized in Shanghai, China from April 10 to May 19, 2022. Eligibility requirements included if patients were aged from 18 to 90 years old, and had severe comorbidities.
The study’s primary endpoint was 28-day all-cause mortality.
“Treatment did not reduce 28-day mortality in COVID-19 patients with severe comorbidities,” the authors wrote. “Paxlovid treatment did not modify SARS–CoV-2 RNA clearance, and did not increase the risk of adverse events.”
Participants were randomly assigned in a 1:1 ratio by a central randomization system to receive either Paxlovid or standard treatment. The patients in the experimental arm received the antiviral at a dose of 300 mg nirmatrelvir [two tablets] + 100 mg ritonavir [one tablet], administered every 12 h for 5 days, in addition to standard treatment based on Guidelines on the Diagnosis and Treatment of COVID-19. In the control arm of the study, patients received standard care included antivirus, anticoagulant therapy, prone position ventilation, awake prone positioning, corticosteroid therapy, and nutrient support.
A total of 132 patients were randomized and assigned to the Paxlovid arm, and 132 patients were randomized and assigned to receive standard treatment. 2 patients discontinued treatment in Paxlovid plus standard treatment group and 1 patient discontinued in the standard treatment group, 2 patients changed from the standard treatment group to Paxlovid treatment group.
“In the intent-to-treat analysis, there were 8/132 deaths in the control arm and 5/132 in the Paxlovid arm on day 28 (ARD = 2.27, 95%CI: −2.94 to 7.49),” the authors wrote.
The authors acknowledged the novelty of this study. “To our knowledge, this is the first study that evaluated the efficacy and safety of Paxlovid therapy in severe hospitalized patients with the Omicron variant infection.”