N Engl J Med

Tecovirimat shows limited efficacy for clade I MPXV

April 18, 2025

Although tecovirimat was deemed safe with no safety concerns, it didn’t significantly shorten the duration of lesion resolution in patients with clade I MPXV infection.

Study details: This double-blind, randomized, placebo-controlled trial evaluated the efficacy and safety of tecovirimat in patients with clade I monkeypox virus (MPXV) infection in the Democratic Republic of Congo. A total of 597 patients with ≥1 MPXV skin lesion and positive PCR results were randomized to receive either tecovirimat or placebo, with all patients receiving supportive care. The primary endpoint was the time to lesion resolution.

Results: Median time to lesion resolution was 7 days for the tecovirimat group and 8 days for the placebo group, with a competing-risks hazard ratio of 1.13 (95% confidence interval [CI] 0.97 - 1.31; P=0.14). Mortality was 1.7%, lower than the 4.6% case fatality rate reported in the DRC in 2023. Adverse events were similar between groups, occurring in 72.9% of the tecovirimat group and 70.5% of the placebo group, with serious adverse events reported in 5.1% and 5.0%, respectively.

Source:

PALM007 Writing Group; Ali R, et al. (2025, April 17). N Engl J Med. Tecovirimat for Clade I MPXV Infection in the Democratic Republic of Congo. https://pubmed.ncbi.nlm.nih.gov/40239067/