乌鸦传媒

Oral tecovirimat (Tpoxx) for monkeypox was well tolerated and nearly all patients' symptoms resolved after 2 weeks of treatment, a small cohort study found.

Among 25 patients given the antiviral on a compassionate use basis, 40% reported no longer having lesions by day 7, while 93% had no further lesions or pain at day 21, said Angel Desai, MD, MPH, and colleagues from the University of California Davis Medical Center in Sacramento.

However, due to the uncontrolled nature of the study, it was not possible to know for sure whether improvements were due to treatment or due to the natural course of the infections, according to their .

"In this preliminary study, oral tecovirimat was well tolerated by all patients with monkeypox infection, with minimal adverse effects," the team wrote.

Side effects included fatigue in seven patients, headache in five, nausea in four, itchiness in two, and diarrhea in two. "Adverse effects could not always be differentiated from symptoms related to the infection," Desai's group noted.

Tecovirimat is an FDA-approved drug for smallpox that "inhibits p37, a protein involved in release of enveloped virus, dissemination, and viral virulence," the researchers explained. In vitro testing has shown activity against both smallpox and monkeypox, and the agent appears to have a favorable clinical safety profile based on the experience of healthy volunteers.

The current study involved 25 self-reported male outpatients who were referred to the University of California Davis Medical Center mostly from the Sacramento County Department of Public Health. They received tecovirimat following a positive PCR test between June 3 and August 13 and had disseminated disease or lesions on the face or genitals.

Median participant age was 40.7 years (range 26-76). Symptoms had been present for a mean of 12 days (range 6-24). Genital and/or perianal lesions were present in 23 patients, and a little less than half of the cohort had 10 or more lesions. Three-fourths of the patients presented with fever, a third had headache, seven had fatigue, and five patients had sore throat. Chills were reported in five of the individuals, backache in three, myalgia in two, and nausea and diarrhea in one each.

Nine patients had HIV (24%), one was vaccinated for smallpox more than 25 years earlier, and four had received a single dose of the Jynneos vaccine at the start of their symptoms -- all four of these patients were HIV-negative.

All patients received oral tecovirimat over 14 days, given every 8 or 12 hours, dosed according to weight and taken within 30 minutes of a meal containing moderate to high fat content for improved bioavailability. Patients had follow-up in-person or telephone interviews on days 7 and 21.

One patient reported new lesions on day 7, and consequently took the medication for an additional 7 days (21 days in total). That patient was one of two given an increased dose of tecovirimat due to a delayed clinical response.

At 21 days, 23 of the patients said they had recovered, meaning all lesions had crusted or fallen off; one patient had new lesions; and one patient reported no new lesions, but had not yet fully recovered. None of the patients in the study required hospitalization.

Study limitations, the researchers said, included the small number of patients, the lack of a control group, and selection bias. "Additional large-scale studies are needed to elucidate antiviral efficacy, dosing, and adverse events," Desai and colleagues said.

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