Inosine pranobex was associated with a reduction in mortality in COVID-19 by over 22%, as reported in a retrospective study utilizing complete health data from the Czech national registry

OBJECTIVES: Inosine pranobex (IP), an immunomodulatory agent with antiviral properties approved for the treatment of COVID-19 in various countries, still awaits confirmation of its effectiveness in larger clinical studies. METHODS: A retrospective cohort study utilizing data from the Czech national registry evaluated the efficacy of IP in COVID-19 patients from March 2020 to September 2023. The study analyzed 67841 IP recipients who were exactly matched in a 1:2 ratio with 135682 controls based on age, sex, comorbidities, COVID-19 treatment, vaccination status, and postinfection immunity. The study examined separately pre-Omicron (2020-2021) and Omicron (2022-2023) periods. The primary outcome was the Case Fatality Rate (CFR) assessed at three months following a confirmed COVID-19 diagnosis. RESULTS: In the pre-Omicron period, the CFR for IP recipients was 1.65% (697/42346) compared to 2.11% (1788/84692) in the control group, indicating a 22% reduction in mortality (RR 0.78, 95% CI 0.71-0.85, P < 0.0001). In the Omicron period, the CFR for IP recipients was 0.13% (32/25495) compared to 0.35% (181/50990) in the control group, indicating a 65% reduction in mortality (RR 0.35, 95% CI 0.24-0.51, P < 0.0001). CONCLUSIONS: IP administration in COVID-19 patients was associated with reduced mortality, supporting the need for further investigation of its therapeutic potential.