Safety, immunovirological, and CNS effects of PD-1 inhibition in people with HIV without malignancy

Checkpoint inhibitors are being explored for chronic central nervous system (CNS) infections such as HIV, but safety data in the absence of malignancy are limited. In this phase I, non-randomized study, six virally suppressed individuals with HIV received a single dose of pembrolizumab to assess safety and effects on immune, virologic, and CNS parameters. Over 12 months, 29 adverse events occurred, all grade 1-2, with no serious events. HIV immune responses and viral loads were unchanged, although transient CSF viral increases occurred in two participants. A single dose pembrolizumab appears safe, supporting evaluation of repeated dosing.