Safety and Immunotherapeutic Activity of an Anti-PD-1 Antibody (Cemiplimab) in Participants With HIV-1 on Suppressive cART

This study evaluated the safety and immunotherapeutic activity of an anti‐PD‐1 antibody (cemiplimab) in participants with HIV‐1 on combination antiretroviral therapy (cART) who have plasma less than the quantification limit of an FDA‐approved assay and CD4+ T cell counts ≥350/mm^3. Participants were planned to be enrolled into three sequential dose‐rising cohorts. Participants in each cohort received infusions of either cemiplimab or placebo, with planned administration at study entry (Day 0) and Week 6, for a total of two infusions. All participants continued their non‐study provided ART regimen. Enrollment in the second and third cohorts would only open after all participants in the previous cohort had reached week 12 and an evaluation of safety outcomes established that it is safe to dose escalate. Participants had screening and pre‐entry visits and attended study visits on Day 0 and Weeks 1, 2, 4, 6, 7, 8, 10, 12, 16, 20, 24, 28, 36, and 48. Participants were followed for 48 weeks. Due to observed adverse events which were deemed possibly related to study treatment in two of four treated participants, the study was terminated and did not enroll further participants. The two participants who had adverse events did not receive the second infusion. The treated participants were followed for the planned 48 weeks, while the placebo participant was not followed after a final study visit at week 7.