Effectiveness of nirmatrelvir/ritonavir (Paxlovid®) in preventing hospitalisation and death among COVID-19 patients: a prospective cohort study

• Published in: Medical journal of Malaysia Vol. 78; no. 5; p. 602
• Main Authors: Chew, L S, Lim, X J, Chang, C T, Kamaludin, R S, Leow, H L, Ong, S Y, Saharuddin, N, Sanusi, N A, Kamaruzaman, N, Kamarruddin, Z, Philip, R
• Format: Journal Article
• Language: English
• Published: 01.09.2023
• ISSN: 0300-5283

Previous trials and real-world studies have shown that nirmatrelvir/ritonavir (Paxlovid®) reduces hospitalisation and deaths in symptomatic, high-risk, nonsevere COVID-19 patients. However, there was a scarcity of data on its effectiveness in the local setting. This study aimed to determine the effectiveness of Paxlovid® in reducing hospitalisation and mortality among COVID-19 patients and to identify the types of adverse events that occur after taking Paxlovid®.INTRODUCTIONPrevious trials and real-world studies have shown that nirmatrelvir/ritonavir (Paxlovid®) reduces hospitalisation and deaths in symptomatic, high-risk, nonsevere COVID-19 patients. However, there was a scarcity of data on its effectiveness in the local setting. This study aimed to determine the effectiveness of Paxlovid® in reducing hospitalisation and mortality among COVID-19 patients and to identify the types of adverse events that occur after taking Paxlovid®.A two-arm prospective cohort study was conducted among adult patients with COVID-19 categories 2 and 3 treated with Paxlovid® and a matched control group. A standard risk-stratified scoring system was used to establish Paxlovid® eligibility. All patients who were prescribed Paxlovid® and took at least one dose of Paxlovid® were included in the study. The control patients were selected from a centralised COVID-19 patient registry and matched based on age, gender and COVID-19 stage severity.MATERIALS AND METHODSA two-arm prospective cohort study was conducted among adult patients with COVID-19 categories 2 and 3 treated with Paxlovid® and a matched control group. A standard risk-stratified scoring system was used to establish Paxlovid® eligibility. All patients who were prescribed Paxlovid® and took at least one dose of Paxlovid® were included in the study. The control patients were selected from a centralised COVID-19 patient registry and matched based on age, gender and COVID-19 stage severity.A total of 552 subjects were included in the study and evenly allocated to the treatment and control groups. There was no statistically significant difference in 28-day hospitalisation after diagnosis [Paxlovid®: 26 (9.4%), Control: 34 (12.3%), OR: 0.74; 95%CI, 0.43-1.27; p=0.274] or all-cause death [Paxlovid®: 2 (0.7%), Control: 3 (1.1%), OR 1.51; 95%CI, 0.25-9.09; p=0.999]. There was no significant reduction in hospitalisation duration, intensive care unit admission events or supplementary oxygen requirement in the treatment arm. Ethnicity, COVID-19 severity at diagnosis, comorbidities and vaccination status were predictors of hospitalisation events.RESULTSA total of 552 subjects were included in the study and evenly allocated to the treatment and control groups. There was no statistically significant difference in 28-day hospitalisation after diagnosis [Paxlovid®: 26 (9.4%), Control: 34 (12.3%), OR: 0.74; 95%CI, 0.43-1.27; p=0.274] or all-cause death [Paxlovid®: 2 (0.7%), Control: 3 (1.1%), OR 1.51; 95%CI, 0.25-9.09; p=0.999]. There was no significant reduction in hospitalisation duration, intensive care unit admission events or supplementary oxygen requirement in the treatment arm. Ethnicity, COVID-19 severity at diagnosis, comorbidities and vaccination status were predictors of hospitalisation events.In this two-arm study, Paxlovid® did not significantly lower the incidence of hospitalisation, all-cause death and the need for supplemental oxygen. Adverse effects were frequent but not severe. Paxlovid® efficacy varied across settings and populations, warranting further real-world investigations.CONCLUSIONIn this two-arm study, Paxlovid® did not significantly lower the incidence of hospitalisation, all-cause death and the need for supplemental oxygen. Adverse effects were frequent but not severe. Paxlovid® efficacy varied across settings and populations, warranting further real-world investigations.