Tecovirimat for mpox: Does immunocompromised, HIV status affect clinical outcomes?

Clinical outcomes of mpox (previously monkeypox) infection following treatment with tecovirimat are similar between patients with HIV infection and those without immunocompromised conditions, according to study results published in Open Forum Infectious Disease.

Researchers in New York conducted a retrospective chart review between July and October 2022 to identify and evaluate the clinical features and outcomes of persons with mpox who received tecovirimat through the Centers for Disease Control and Prevention’s expanded-access investigational new drug protocol. Patients were included if they had suspected or laboratory-confirmed mpox infection and were prescribed tecovirimat at clinical sites within Mount Sinai Health System in New York. Clinical characteristics and outcomes were analyzed using chi-square and Wilcoxon testing.

The final analysis included a total of 130 patients, of whom 92.3% had laboratory-confirmed and 7.7% had suspected mpox infection. The median patient age was 37 years, 61.5% had HIV infection, 95.4% identified as men, and 93.0% were men who have sex with men. In addition, 14 (10.7%) patients had severe immunocompromised conditions.

The researchers reported no significant differences between the 80 patients with HIV infection and the 46 without any immunocompromised conditions for the following clinical outcomes:

• Hospitalization (16.3% vs 10.9%; P =.41);
• Concurrent bacterial superinfection (12.5% vs 17.4%; P =.45); and
• Clinical recovery (96.2% vs 93.5%; P =.58).

Patients with vs without severe immunocompromised conditions showed no significant difference in the rate of bacterial superinfection (21.4% vs 13.8%; P =.46) or clinical recovery (85.7% vs 97.1%; P =.14). However, severely immunocompromised patients were more likely to be hospitalized (50% vs 9.0%; P <.001) and receive intravenous tecovirimat (14.3% vs 0%; P <.001).

Of 18 patients who were hospitalized, 16.7% required intensive care unit admission, 44.4% were admitted for bacterial superinfection, and the median length of hospitalization was 4 days. Moreover, 72.2% of these patients had HIV infection and 61.5% were not virologically suppressed.

Among 8 hospitalized patients who were evaluated following treatment completion, 7 (87.5%) experienced clinical recovery and 1 required prolonged hospitalization due to evolving disease and bacterial superinfection.

In regard to mpox symptoms, 99.2% of patients had visible, characteristic skin lesions, more than 80% presented with at least 1 sign or symptom suggestive systemic illness, and many had anogenital involvement.

Tecovirimat was prescribed for lesions in sensitive areas in 83.1% of patients, pain in 67.7%, and severe outcomes due to immunosuppression in 22.8%. Lesion improvement was reported for all patients within a median of 3 (IQR, 1-12) days of tecovirimat initiation, with complete resolution reported within a median of 10 (IQR, 3-20) days.

Study limitations include the high rate of loss to follow-up, subjective prescribing patterns, and the small sample size.

The researchers concluded, “The efficacy of tecovirimat in immunocompromised patient populations was beyond the scope of this study but is an important topic for further research.”

By Mabel Chan, PharmD, BCACP

References:

Vo C, Zomorodi R, Silvera R, et al. Clinical characteristics and outcomes of patients with Mpox who received tecovirimat in a New York City health system. Open Forum Infect Dis. Published online November 2, 2023. doi:10.1093/ofid/ofad552