Pembrolizumab Is Safe and Effective in Kaposi Sarcoma

Kaposi sarcoma is a rare cancer type that typically develops in individuals who are immunocompromised. Reduction of immunosuppression has been shown to be a promising treatment for the epidemic and iatrogenic forms of this disease; however, use of immunotherapy treatments in the classic and endemic forms has not been well defined. Delyon and colleagues thus sought to determine the effects of the PD-1 inhibitor pembrolizumab in patients with classic or endemic Kaposi sarcoma through a prospective, multicenter, single-arm phase II clinical trial. The primary endpoint of this study was the investigator-assessed best overall response rate (exceeding 30%) after 6 months of treatment following the AIDS Clinical Trial Group (ACTG) criteria. Secondary endpoints included adverse events (AE), response rate at 3 and 6 months posttreatment, response rate according to lesion number and tumor infiltration, response rate of lymphoedema, time to response, and time to progression. Seventeen patients were enrolled in this study, with two demonstrating a complete response, 10 showing a partial response, and five having stable disease. The best overall response rate was 71% (12 of 17 patients) meeting the primary endpoint. Moreover, the estimated median duration of response was 23.4 months. Regarding safety, 13 patients demonstrated at least one treatment-related AE, with two patients showing grade 3 AEs and zero patients showing grade 4 AEs. No treatment-related deaths were observed. Overall, this trial suggests that the use of pembrolizumab in classic and endemic forms of Kaposi sarcoma is safe and has durable antitumor activity, supporting further trials in a larger cohort of patients.

Delyon J, Biard L, Renaud M, Resche-Rigon M, Le Goff J, Dalle S, et al. PD-1 blockade with pembrolizumab in classic or endemic Kaposi's sarcoma: a multicentre, single-arm, phase 2 study. Lancet Oncol 2022;23:491–500.

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