CD4+ T-cell count eligibility by HIV status among participants receiving immunotherapy for cancer diagnoses.

Abstract

12104 Background: The Food and Drug Administration recommends that patients living with HIV (PLWH) with a CD4+ T cell count (CD4) ≥350 cells/µL should generally be eligible for any cancer clinical trial, but there has been a reluctance to enter patients with lower CD4 counts. Patients with relapsed or refractory cancers may also have low CD4 due to initial cancer therapies, irrespective of HIV status. Immune checkpoint inhibitors (ICI) are safe among PLWH with advanced cancer receiving antiretroviral therapy and CD4 >100 cells/µL. We examined the outcomes of immunotherapy trials by HIV and CD4 status among patients receiving ICI for relapsed/refractory cancers. Methods: We conducted a retrospective cohort study of participants who received ICI for relapsed/refractory cancers in 2 trials (1 specifically in PLWH with CD4 >100 only) from the National Cancer Institute. Primary outcomes were to assess relationship between HIV status and baseline CD4 (<350 vs ≥350 cells/µL) and other characteristics. We stratified 3-year survival by CD4 in PLWH and HIV-negative participants with HPV-related cancers. The Kaplan-Meier method was used to estimate survival rates. Results: Eighty-three participants were included: 26 (31.3%) were HIV-positive and received pembrolizumab and 57 (68.7%) were HIV-negative and received bintrafusp alfa. HIV-negative participants had relapsed HPV related malignancies (cervix, anal, head and neck) whereas participants with HIV had both viral and non-viral associated cancers (Table). While the median screening CD4 was significantly lower among PLWH than HIV-negative participants, there was no difference in the proportion with CD4 <350 (p=0.1). When restricted to HPV related malignancies, 3-year survival rates were 32.2% for CD4 <350 and 21.2% for CD4 ≥350 (p=0.7). Conclusions: In this retrospective study of ICI clinical trials in relapsed and refractory malignancies, there was no significant difference in baseline CD4 (<350 vs ≥350 cells/µL) by HIV status; 50% of HIV-negative participants had CD4<350 cells/µL. Patients with HIV should be included in ICI studies, and CD4 thresholds lower than 350 cells/µL should be considered as to not unfairly exclude PLWH with cancer.[Table: see text]