The NIH has commenced a phase 3 randomized, placebo-controlled, double-blind clinical trial STOMP (Study of Tecovirimat for Human Monkeypox Virus; A5418) investigating the safety and efficacy of the antiviral drug tecovirimat in patients with monkeypox. The recruitment of patients, both adults and children, with monkeypox infection in the United States is now on. A total of 530 volunteers will be enrolled. Tecovirimat is currently available for US patients through an expanded access or “compassionate use” request put in by the clinicians. The multicenter trial is being led by the AIDS Clinical Trials Group (ACTG), which is the largest body engaged in global HIV research.

All patients with severe monkeypox and persons at risk of severe disease including children, pregnant and lactating women, immunocompromised patients or those with active inflammatory skin disease will be administered the drug in the open-label arm of the trial. Other patients would be randomized to receive tecovirimat or placebo orally for 14 days in a 2:1 ratio. Patients who develop severe disease or experience severe pain will have the option to move to the open label arm.

The impact of the drug on pain scores, progression to severe disease, clearance of monkeypox virus will be studied in addition to its safety. Pediatric dosing and safety will also be examined. Optimal dosing for pregnant women will also be a part of the study.

The follow up period will be 8 weeks during which the participants will be required to maintain a symptom diary, carry out daily self-skin examination for the status of skin lesions and visit the clinic, both virtual and in-person. Blood samples and swabs from skin lesions will be collected.

Sources

1. National Institutes of Health (NIH) Press Release, September 9, 2022.
2. AIDS Clinical Trial Group (ACTG) Press Release, September 9, 2022.