Early Tecovirimat Treatment for Mpox Disease Among People With HIV

<bold>Importance</bold> Despite a lack of effectiveness data in humans, tecovirimat was widely prescribed to people with HIV (PWH) with mpox during the 2022 mpox epidemic, particularly PWH with low CD4(+) T-cell counts or severe mpox clinical manifestations.<bold>Objective</bold> To evaluate if PWH with mpox who were treated with tecovirimat within 7 days of symptom onset were less likely to have mpox disease progression.<bold>Design, Setting, and Participants</bold> This cohort study included PWH diagnosed with mpox at 4 hospitals in Atlanta, Georgia, between June 1 and October 7, 2022. Patients were grouped according to whether they were treated with tecovirimat within 7 days of mpox symptom onset (early tecovirimat cohort) or they did not receive tecovirimat or received the drug 7 or more days after symptom onset (late or no tecovirimat cohort). Multivariable logistic regression models were used to identify factors associated with progression of mpox disease. The 2 cohorts were then matched 1:1 using propensity scores based on the identified factors, and mpox disease progression was compared.<bold>Exposures</bold> Treatment with tecovirimat within 7 days of mpox symptom onset.<bold>Main Outcome and Measures</bold> Progression of mpox disease, defined as the development of at least 1 severe mpox criterion established by the US Centers for Disease Control and Prevention, after symptom day 7.<bold>Results</bold> After propensity score matching, a total of 112 PWH were included in the analysis; 56 received tecovirimat within 7 days of mpox symptom onset (early tecovirimat group) and 56 were either treated later or did not receive tecovirimat (late or no tecovirimat group). In the early tecovirimat group, the median (IQR) age was 35 (30-42) years; 54 individuals (96.4%) were cisgender men, 46 (82.1%) were Black individuals, and 10 (17.9%) were individuals of other races (American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, or White) or unknown race. In the late or no tecovirimat group, the median (IQR) age was 36 (32-43) years; 54 (96.4%) were cisgender men, 49 (87.5%) were Black individuals, and 7 (12.5%) were individuals of other races or unknown race. Mpox disease progression occurred in 3 PWH (5.4%) in the early tecovirimat group and in 15 PWH (26.8%) in the late or no tecovirimat group (paired odds ratio, 13.00 [95% CI, 1.71-99.40]; P = .002).<bold>Conclusion and Relevance</bold> Results of this cohort study support starting tecovirimat in all PWH as soon as an mpox diagnosis is suspected. Additional research is warranted to confirm these findings.