14 May 2025

JAK Inhibitors for COVID-19: New Insights from an Individual Participant Data Meta-Analysis

Clinical guidelines have varied in interpreting evidence on JAK inhibitors for adults hospitalized due to COVID-19. Previous systematic reviews pooled six randomized trials, showing clinical benefits, but emphasized the need for more high-quality data especially regarding safety and certain subgroups.

This study, published in The Lancet Respiratory Medicine and initiated by EU-RESPONSE, analyzed data from 12 trials, revealing significant survival benefits, faster hospital discharge, and reduced need for respiratory support. No credible effect modifications were found across key subgroups, except for age, whereby younger patients experienced larger relative benefits. Concerns about safety in vaccinated individuals were also refuted.

With over 96% of global trial data on this topic included, this study provides the most comprehensive evidence. It also highlights the need for timely data sharing to influence clinical guidelines in real-time – as emphasized by the accompanying editorial.

The study protocol was registered, the analysis code is available here, and project updates provided on www.jakinhibitoripdma.org.

Thank you to all involved trial teams and participants; the study has received funding from the EU’s Horizon 2020 research and innovation programme under grant agreement number 101015736.