Clinicians have focused on tecovirimat for mpox treatment as a potential solution to the global outbreak. However, recent phase 3 trial results reveal that this antiviral does not provide significant clinical benefits for adults with Clade II infection. Researchers conducted the international STOMP trial to address the uncertainty surrounding the drug’s efficacy in humans. The findings suggest that we must look beyond this specific antiviral for routine management.
The international, double-blind, randomized trial enrolled over 400 participants. Most of these individuals had laboratory-confirmed mpox with active lesions. Consequently, the team assigned participants to receive either oral tecovirimat or a placebo for 14 days. The primary goal was to measure the time until clinical resolution of all lesions. Therefore, the study provided a clear comparison between the treatment and standard supportive care.
Efficacy of Tecovirimat for Mpox Treatment
The results demonstrate no substantial difference between the treatment and placebo groups. Specifically, the clinical resolution rate by day 29 was nearly identical. It reached 83% for the drug group and 84% for the placebo group. Furthermore, the treatment did not reduce severe pain effectively. The difference in pain reduction was only 0.1 point on a 10-point scale. Additionally, viral DNA clearance remained similar across both study arms.
Importantly, the study confirmed that tecovirimat is safe. Adverse events of grade 3 or higher occurred in only 4% of the treatment group. Therefore, while the drug is well-tolerated, it does not seem to offer therapeutic advantages for typical Clade II cases. Indian clinicians should prioritize supportive care and pain management for patients with mild to moderate disease. Consequently, this shift in focus ensures better resource allocation during outbreaks.
Frequently Asked Questions
Q1: Does tecovirimat reduce pain in mpox patients?
No, the STOMP trial found no significant reduction in pain for patients treated with tecovirimat compared to those on a placebo.
Q2: Is tecovirimat safe for human use?
Yes, the trial confirmed that the drug has a strong safety profile with adverse event rates similar to the placebo group.
References
- Zucker J et al. Tecovirimat for the Treatment of Mpox. N Engl J Med. 2026 Feb 26. doi: 10.1056/NEJMoa2506495. PMID: 41740032.
- ACTG Announces Publication of STOMP Results in the New England Journal of Medicine. GlobeNewswire. Feb 25, 2026.
- NIH study finds tecovirimat was safe but did not improve mpox resolution or pain. NIH News Release. March 12, 2025.