UC San Diego

Patients with human immunodeficiency virus (HIV) infection have a high risk of developing virally-mediated cancers. These tumors have several features that could make them vulnerable to immune checkpoint inhibitors (ICIs) including, but not limited to, increased expression of the CTLA-4 and PD-1 checkpoints on their CD4+ T cells. Even so, HIV-positive patients are generally excluded from immunotherapy cancer clinical trials due to safety concerns. Hence, only case series have been published regarding HIV-positive patients with cancer who received ICIs, but these reports of individuals with a variety of malignancies demonstrate that ICIs have significant activity, exceeding a 65% objective response rate in Kaposi sarcoma. Furthermore, high-grade immune toxicities occurred in fewer than 10% of treated patients. The existing data suggest that the underlying biologic mechanisms that mediate development of cancer in HIV-infected patients should render them susceptible to ICI treatment. Preliminary, albeit limited, clinical experience indicates that checkpoint blockade is both safe and efficacious in this setting. Additional clinical trials that include HIV-positive patients with cancer are urgently needed.