Safety, Immunovirologic, and Central Nervous System Effects of PD-1 Inhibition in People With HIV Without Malignancy

Checkpoint inhibitors are being explored for chronic central nervous system infections such as HIV, but safety data in the absence of malignancy are limited. In this phase 1 nonrandomized study, 6 individuals with virally suppressed HIV received a single dose of pembrolizumab to assess its safety and effects on immune, virologic, and central nervous system parameters. Over 12 months, 29 adverse events occurred, all grade 1 or 2, with no serious events. HIV immune responses and viral loads were unchanged, although transient CSF viral increases occurred in 2 participants. A single dose of pembrolizumab appears safe, supporting evaluation of repeated dosing.