Study of Tecovirimat for Human Mpox Virus

Summary

The purpose of this study was to see if tecovirimat is safe and successful at treating mpox. The main questions were whether tecovirimat reduced time to lesion resolution and pain compared to placebo (no treatment).

Timeline

Start

2022-09-08

Primary completion

2024-10-23

Completion

2025-02-22

Outcome

Missed primary endpoint

Stopped: “DSMB recommendation due to statistical futility”

registry analysis (superiority test); Tecovirimat (Arm A) vs Placebo (Arm B); p = 0.89; Subdistribution hazard ratio 0.98 (98.09% CI 0.74 to 1.31) NCT05534984 ↗

paper By day 29, the estimated cumulative incidence of clinical resolution was 83% with tecovirimat and 84% with placebo PMID 41740032 ↗

Publications

• Zucker J, Fischer WA 2nd, Zheng L, McCarthy C, Saha PT, Javan AC, Greninger A, Hamill MM, Leslie K, Brooks KM, Berardi J, Smith D, Hosey L, Aldrovandi G, Ferbas K, Day C, Bender Ignacio RA, Bolan R, Glesby MJ, Landovitz RJ, Luetkemeyer AF, Sierra Madero J, Gandhi RT, Nachman S, Eron J, Currier JS, Wilkin T; STOMP/A5418 Investigators. Tecovirimat for the Treatment of Mpox. N Engl J Med. 2026 Feb 26;394(9):884-895. doi: 10.1056/NEJMoa2506495.
• Chenchula S, Atal S, Ghanta MK, Uppugunduri CR, Karunakaran S, Amerneni KC, Sarma P, Prakash S, Amerneni LS, Padmavathi R, Anitha K, Sri Varshini T, Vishnu Vardhan K, Kaore S, Sadasivam B. Emerging variants of Mpox virus and tecovirimat resistance: Genomic insights and implications for treatment strategies. Virology. 2025 Jul;608:110532. doi: 10.1016/j.virol.2025.110532. Epub 2025 Apr 12.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	Tecovirimat	Small molecule	33.3 mg	Oral
Subject	Tecovirimat	Small molecule	50 mg	Oral
Subject	Tecovirimat	Small molecule	100 mg	Oral
Subject	Tecovirimat	Small molecule	200 mg	Oral
Subject	Tecovirimat	Small molecule	400 mg	Oral
Subject	Tecovirimat	Small molecule	600 mg	Oral

Indications

No indication recorded.