1611. Real-World Effectiveness and Tolerability of Bictegravir/Emtricitabine/Tenofovir Alafenamide (B/F/TAF) in Treatment-Experienced People With HIV and a History of Antiretroviral Drug Resistance Mutations

• Published in: Open forum infectious diseases 2023-11, Vol.10 (Supplement_2)
• Main Authors: Trottier, Benoit, Bonnet, Fabrice, Garcia-Deltoro, Miguel, Andreoni, Massimo, Boffito, Marta, van Welzen, Berend J, Turner, Dan, McConkey, Sam, Watanabe, Dai, Lu, Po-Liang, Gündüz, Alper, Thorpe, David, D’Antoni, Michelle L, Cassidy, Tali, Marongiu, Andrea, Weinberg, Amy R, Haubrich, Richard, Scholten, Stefan
• Format: Article
• Language: English
• ISSN: 2328-8957; 2328-8957
• DOI: 10.1093/ofid/ofad500.1446

Abstract Background BICSTaR is an ongoing, multinational, observational cohort study evaluating the real-world effectiveness and safety of B/F/TAF in antiretroviral therapy (ART) treatment-naïve and treatment-experienced (TE) people with HIV. Methods This analysis of BICSTaR included TE virologically suppressed people with HIV who had started B/F/TAF in clinical practice with/without present/past evidence of HIV drug primary resistance mutations (PRMs). All had viral load (VL) data at baseline (BL). We report virologic and other outcomes at 12 months (M). Results In the overall population, the most common ARTs taken immediately before B/F/TAF were E/C/F/TAF (27%), DTG+F/TAF (9%) and ABC/DTG/3TC (8%). BL genotypic drug resistance testing data were available for 441/996 (44%) participants (ppts); most tests were historic and performed > 60M before starting B/F/TAF (Table 1). Of 441 ppts with BL resistance data, 105/441 (24%) had present/past evidence of PRMs: 13% to NRTI, 11% to NNRTI, 6% to PI, 0.2% to INSTI. The most common PRMs were M184V/I (39 [37%]), ≥ 1 thymidine analog mutation (TAM; 40 [38%]), K103N/S in reverse transcriptase (23 [22%]) and M46I/L in protease (13 [12%]). Primary resistance to > 1 ART drug class was observed in 40 (38%) ppts with PRMs. Ppts with preexisting PRMs were older (≥ 50 years), had more prior ARTs and more prior virologic failure, and had a longer time between HIV diagnosis and starting B/F/TAF versus those without PRMs. At 12M, effectiveness (HIV-1 RNA < 50 copies/mL; missing VL data = excluded) was maintained in 78 (99%) and 739 (98%) ppts with, versus without, any BL PRMs, respectively; 32/33 (97%) of those with M184V/I alone; 13/13 (100%) with M184V/I + 1–2 TAMs; and 2/2 (100%) with M184V/I + ≥ 3 TAMs at BL. No treatment-emergent PRMs to B/F/TAF were reported. Drug-related adverse events (DRAEs) occurred in 17 (16%) ppts with PRMs versus 113 (13%) without PRMs; serious DRAEs occurred in 2 ppts, both had PRMs at BL. Overall, 98/996 (10%) ppts switched from B/F/TAF to other ARTs (15 [14%] with PRMs, 83 [9%] without PRMs). Additional outcomes are shown in Table 2. Conclusion After 12 months, virologically suppressed people with HIV initiating B/F/TAF in routine clinical practice maintained high rates of effectiveness despite the presence of PRMs (including M184V/I). Disclosures Benoit Trottier, MD, Gilead: Advisor/Consultant|Gilead: Honoraria|Merck: Advisor/Consultant|Merck: Honoraria|ViiV: Advisor/Consultant|ViiV: Honoraria