Tecovirimat safe to use in patients infected with monkeypox

Tecovirimat (Tpoxx) was well tolerated by individuals who had the monkeypox viral infection, says an article published in Centers for Disease Control and Prevention.

Tobolowsky and colleagues recruited 549 patients for this trial, of whom 99.8% received oral tecovirimat treatment. There were 97.7% men and a median age of 36.5 and detailed information was provided for 369 patients. Of the 464 patients who provided information about their race and ethnicity, 38.8% identified as white, 34.7% as Hispanic or Latino, and 17.9% as Black or African American. Lesions affected less than 10% of the bodies of around two-thirds of patients, and 75% to 100% of the bodies of 4.7% of patients, respectively. After the beginning of symptoms, patients received their first dosage of tecovirimat on average 7 days later (interquartile range, 5-10).

The key findings were:

1. Among over 300 patients taking tecovirimat under the FDA-regulated Expanded Access Investigational New Drug (EA-IND) protocol, 6.9% were hospitalized after symptom onset, with a median duration of hospitalization of 4 days.

2. Of 255 patients with available data, the median time to subjective improvement after starting treatment was 3 days, with no differences noted between patients with HIV positivity and those with no information on HIV status. Furthermore, among 317 patients with available outcome data, 72.6% recovered with or without sequelae, while 27.4% were reported to be not yet recovered, though 78 had not yet completed the standard 14-day tecovirimat treatment course.

3. 13.1% of patients with data reported developing new lesions within the first week of therapy, whereas 31.8% said all lesions crusted over and cured.

4. 13.5% of patients said they developed new lesions in the second week, while 49.7% said the lesions crusted over and healed.

5. Following therapy, 2.2% reported developing new lesions, whereas 89.5% reported healed lesions with a fresh layer of skin under the scab.

6. 3.5% of the 340 participants experienced negative side effects, which included headache, nausea, vision impairment, weakness, and psychiatric hospitalization.

In conclusion, these results suggest continuing access to tecovirimat therapy during the present monkeypox outbreak because the drug is typically well tolerated.

Reference: 

O'Laughlin, K., Tobolowsky, F. A., Elmor, R., Overton, R., O'Connor, S. M., Damon, I. K., Petersen, B. W., Rao, A. K., Yu, P., Yu, Y., Campbell, C., … Cheng, M. (2022). Clinical Use of Tecovirimat (Tpoxx) for Treatment of Monkeypox Under an Investigational New Drug Protocol-United States, May–August 2022. In MMWR. Morbidity and Mortality Weekly Report (Vol. 71, Issue 37). Centers for Disease Control MMWR Office.https://doi.org/10.15585/mmwr.mm7137e1