324. Outcomes of Immunomodulatory and Biologic Therapy in People Living with HIV: A Report from Two Academic Hospitals

BACKGROUND: The use of immunomodulatory drugs (IMDs) is increasingly common. However, data on outcomes of IMD use in people living with HIV (PLWH) are limited and may be biased due to selective reporting of certain outcomes. Institution-level data reflecting patient-time at risk have not been described. METHODS: We systematically identified all PLWH prescribed non-steroidal IMDs from 2012 to 2019 at two centers. We defined a treatment episode (TE) as an uninterrupted period on a particular IMD regimen. Patients contributed multiple TEs if interrupting or switching therapy. We excluded those with lymphoproliferative disorders or transplants. We quantified infections and blips, defined as a detectable viral load following an undetectable result. RESULTS: 35 patients contributed 55 TEs comprising 24,020 patient-days at risk. 29/35 (83%) were male, median age was 53 (IQR 39–59), median CD4 nadir was 197 (IQR 100–314), and 12/35 (34%) had a prior opportunistic infection. TEs utilized TNF inhibitors (19/55, 35%), PD-1 inhibitors (11/55, 20%), antimetabolites (7/55, 13%), interleukin inhibitors (7/55, 13%), and other agents (7/55, 13%). 4/55 (7%) involved in dual therapy. 32/35 (94%) patients were on antiretroviral therapy (ART) at IMD initiation; one was off therapy, one already on IMDs-acquired HIV, and one was an elite controller. Median CD4 count was 472 (IQR 337–807); CD4 was < 500 in 28/55 TEs (51%). Preceding plasma HIV RNA was undetectable in 36/55 (65%) TEs. Of these, 18 (50%) were associated with a viral blip within 1 year; one blip was >200 copies and none resulted in sustained viremia. Compared with other agents, PD-1 inhibitors were associated with a higher blip rate (incidence rate ratio 4.3, 1.3–12.3). 17/55 (32%) TEs were initiated with detectable plasma HIV RNA, which declined on ART in 13/15 (87%) TEs with follow-up testing; one patient stopped ART and one later suppressed. 9/55 (16%) TEs involved an infectious complication (7 soft-tissue infections, 2 pneumonias), although none was clearly attributed to IMDs. 36/55 (65%) TEs had good therapeutic response. CONCLUSION: IMDs can be used without major complications in PLWH on ART, including those not yet suppressed or with CD4 counts < 500. PD-1 inhibitors may be associated with a higher rate of viral blips, although the clinical significance is unclear. DISCLOSURES: All authors: No reported disclosures.