Pom/Nivo (IMiD + PD-1 blockade) hits 100% response in evaluable Kaposi sarcoma, with manageable neutropenia

Pomalidomide (Pom), an oral immunomodulatory drug that augments T-cell co-stimulation, was combined with nivolumab (Nivo), an anti–PD-1 antibody, in a 3+3 Phase I dose-escalation trial in advanced virus-associated malignancies (EBV/KSHV/HPV), enrolling 16 patients including 9 people with HIV on ART (median CD4 253 cells/mm³; range 61–616) (n=16; NCT04902443). After a median 7 cycles, the main grade ≥3 toxicity was neutropenia (G3/4 in 5 patients) managed with growth factor support and Pom dose reductions; one DL1 dose-limiting toxicity occurred (G3 dyspnea), and the Pom maximum tolerated dose was 4mg (21/28 days). Among 11 patients receiving ≥3 cycles (5 not response-evaluable), all 4 Kaposi sarcoma patients responded (2 CR, 2 PR; 100%); outside KS, activity was limited (PEL SD; HPV-malignancies 1/4 SD; nasopharyngeal carcinoma 1/2 SD; 4 PD)—notably, KS systemic SOC options like pegylated liposomal doxorubicin or paclitaxel typically yield ~46–59% response rates, so 4/4 responses is directionally compelling but very small-n.