CROI 2025 Abstract eBook

Abstract eBook

Oral Abstracts

197

Response to HIV Treatment After Long-Acting Cabotegravir Preexposure Prophylaxis in HPTN 083 Raphael J. Landovitz 1 , Jessica M. Fogel 2 , Zhe Wang 3 , Estelle Piwowar-Manning 2 , Elias Konstantine Halvas 4 , Deborah J. Donnell 3 , Marybeth McCauley 5 , Robinson Cabello 6 , Keren Middelkoop 7 , Lydia Soto-Torres 8 , James F. Rooney 9 , Alex Rinehart 10 , Beatriz Grinsztejn 11 , Susan H. Eshleman 2 , for the HPTN 083 Study Team 1 University of California Los Angeles, Los Angeles, CA, USA, 2 The Johns Hopkins University School of Medicine, Baltimore, MD, USA, 3 Fred Hutchinson Cancer Center, Seattle, WA, USA, 4 University of Pittsburgh, Pittsburgh, PA, USA, 5 Family Health International 360, Durham, NC, USA, 6 Centro Especializado de Salud de VÍA LIBRE, Lima, Peru, 7 Groote Schuur Hospital, Cape Town, South Africa, 8 Division of AIDS, Bethesda, MD, USA, 9 Gilead Sciences, Inc, Foster City, CA, USA, 10 ViiV Healthcare, Durham, NC, USA, 11 Institute de Pesquisa Clinica Evandro Chagas, Rio de Janeiro, Brazil Background: Data on antiretroviral therapy (ART) outcomes in persons who acquire HIV with long-acting cabotegravir (CAB-LA) pre-exposure prophylaxis (PrEP) are limited. We evaluated ART outcomes in CAB-LA exposed cisgender men and transgender women who have sex with men (MSM/TGW) who acquired HIV in the HPTN 083 trial. ART regimens were selected at study sites; local genotyping results were available in some cases. Methods: Participants diagnosed with HIV after ≥1 CAB-LA injection with >30 days follow-up on ART were included (1st HIV positive visit through 12/1/23). HIV viral load (VL) and HIV genotyping data reported here are from retrospective centralized testing. Results: Response to an initial ART regimen was assessed for 47 participants (Table): 22 on integrase strand transfer inhibitor (INSTI)-based ART and 25 on other ART (14 on efavirenz [EFV]-based ART; 10 on PI-based ART; 1 on PI+INSTI ART). Those with no CAB-LA in the past 6 months were more likely to start INSTI based ART and less likely to have pre-ART INSTI resistance. Median follow-up on ART was shorter for those on INSTI-ART than for those on other ART regimens. The proportion of persons with VL <50 c/mL at the last visit was similar for the two groups. Two participants with pre-ART INSTI resistance started INSTI-ART: one with N155N/H+R263R/K who had a VL of 52 c/mL after 77 days on ART; one with R263K who had VL <50 c/mL from day 112 through day 356 on ART. ART outcomes were also assessed in 7 participants who switched to INSTI-based ART (4 cases above + 3 other cases; 2 from EFV-based ART; 3 from PI-based ART, 2 from PI+INSTI ART; median 2nd regimen follow-up: 219 days, range 145-349). All 7 participants achieved a VL <50 c/mL on the second regimen including one with pre-ART INSTI resistance (Q148R). Conclusions: Ideal PrEP product profiles consider the potential for emergence of resistance to first-line ART. Some persons who acquire HIV with CAB LA-PrEP develop INSTI resistance which could compromise response to INSTI-based regimens. We found similar short-term ART outcomes for MSM/TGW who acquired HIV with CAB-LA PrEP with INSTI-ART vs. other ART regimens. These results should be interpreted with caution, since site location, rationale for ART selection, availability of local resistance testing, and differences in duration of follow-up complicate interpretation of these data. More data are needed to determine optimal ART regimen selection in persons who acquire HIV in the setting of CAB-LA PrEP.

testing algorithm guidelines should consider the risks and benefits of HIV RNA screening in this setting. PILLAR Month 12 Clinical Results: Zero HIV Acquisition and High Persistence With CAB LA for PrEP Nanlesta Pilgrim 1 , Alison Gaudion 2 , Bo Li 3 , Julian A. Torres 4 , William Valenti 5 , Dima Dandachi 6 , Hadrian Holder 7 , Riya Moodley 2 , Todd McKeon 1 , Deanna Merrill 1 , Michael Aboud 1 , Kimberley Brown 1 , Maggie Czarnogorski 2 , Taimur Khan 8 1 ViiV Healthcare, Durham, NC, USA, 2 ViiV Healthcare, Brentford, UK, 3 GSK, Collegeville, PA, USA, 4 Montefiore Medical Center, Bronx, NY, USA, 5 Trillium Health, Rochester, NY, USA, 6 University of Missouri, Columbia, MO, USA, 7 Southwest Community Health Center, Bridgeport, CT, USA, 8 Fenway Health, Boston, MA, USA Background: In 2022, men who have sex with men (MSM) and transgender men (TGM) accounted for 67% and <1% of new US HIV diagnoses, respectively. Additionally, an estimated 15% of MSM, and 3% of TGM, were estimated to be living with HIV in the US. Long-acting (LA) cabotegravir (CAB) administered every 2 months via intramuscular injection is the first and only approved LA medication for HIV-1 pre-exposure prophylaxis (PrEP). We present clinical outcomes through Month (M) 12 with CAB LA in the PILLAR (NCT05374525) study. Methods: PILLAR is a Phase 4 gender-concordant implementation science trial assessing integration of CAB LA at 17 clinics for MSM and TGM. Clinical assessments included HIV incidence, HIV diagnostic testing, persistence (duration for which an individual continued to receive injections), and safety and tolerability. Results: From May 2022 to August 2023, 201 participants enrolled and initiated CAB LA; 6% were TGM, median age (interquartile range) was 35 (29–44) years, 26% were Black, and 38% were Hispanic. Most (78%) had taken oral PrEP in the last 6 months prior to CAB LA initiation. There were no cases of HIV acquisition through M12. At M6 and M12, persistence on CAB LA was 85% (n=171/201) and 72% (n=142/196; excludes 5 participants who completed the study post data cutoff), respectively. A total of 27 (13%; n=26 MSM, n=1 TGM) participants acquired a sexually transmitted infection that was identified through last on-study visit (gonorrhea, n=14; chlamydia, n=12; syphilis, n=7). Most study sites used HIV-1 antigen/antibody (Ag/Ab) testing during screening (94%, n=16/17), 71% (n=12/17) used HIV-1 RNA testing, and 65% (n=11/17) of clinics utilized both HIV-1 Ag/Ab and HIV-1 RNA testing (Table 1). Overall, 70% (n=141/201) of participants completed all injections within the study. Five (2%) participants missed an injection and received oral CAB (n=1) or alternative PrEP (n=4). Adverse events (AEs) related to CAB LA were rare, with injection site pain the most frequently reported (3%, n=6). A total of 11 (5%) participants had AEs leading to discontinuation, most commonly due to injection site pain (n=6). Conclusions: These real-world data obtained from a diverse population support CAB LA as an effective PrEP option associated with high persistence. No cases of HIV acquisition were observed through 12 months irrespective of the testing method(s) used, potentially suggesting a less prescriptive testing guideline.

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Oral Abstracts

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WITHDRAWN

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CROI 2025