The drug tecovirimat appears to be safe and effective for treating the symptoms and skin lesions of monkeypox, a small study suggests.
Tecovirimat (TPOXX) is an antiviral drug for the treatment of smallpox. It works by limiting spread of the virus in the body. The U.S. Centers for Disease Control and Prevention has allowed doctors to prescribe tecovirimat on a "compassionate use basis" to treat adults and children with orthopoxvirus infections, including monkeypox.
"We have very limited clinical data on the use of tecovirimat for monkeypox infection. There is much to learn about the natural progression of the disease and how tecovirimat and other antivirals may affect it," researcher Dr. Angel Desai said in a news release from the University of California, Davis. She is an infectious disease specialist at the university.
The small study included patients seen at UC Davis Medical Center between June 3 and Aug. 13. Patients with skin lesions were offered oral tecovirimat treatment. (More than 9 in 10 had sores in their genital or anal areas.)
The treatment was given every eight or 12 hours, and 25 men with monkeypox completed a course of tecovirimat therapy. All tolerated it well. They were treated for two weeks, except one patient who was treated for 21 days.
A week after starting therapy, 40% of the men's lesions had healed. By day 21, 92% had healed and were pain-free, researchers found.
Side effects of the medicine after a week included fatigue (28%); headache (20%); nausea (16%); itching (8%), and diarrhea (8%).
"We have to be very careful in how we interpret the data. It is hard to differentiate the side effects due to therapy from those caused by the infection," said study co-author Dr. George Thompson, of the UC Davis School of Medicine.
Because the study did not include a control group, researchers said assessing antiviral effectiveness in terms of symptom duration and severity was limited.
The findings were published Aug. 26 in the Journal of the American Medical Association.
A separate study, published earlier this month in the New England Journal of Medicine, also investigated tecovirimat as a treatment for monkeypox.