CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

Results: Of 560 CAB LA for PrEP users identified, 13% were women, 32% Black, 29% Hispanic, and 26% had a BMI ≥30; median age was 31 years (IQR 25-38). Within 12 months prior to CAB LA for PrEP initiation, 42% of individuals had an STI diagnosed and the median number of HIV tests was 3 (IQR: 2, 5). The initiation injections were completed by 498 individuals (89%) who had a median of 4 injections over a median 7 months of follow-up. Of the 498 with ≥2 injections, 7% discontinued CAB LA for PrEP (Table). Over two-thirds of CAB LA users received all injections on-time and 11% missed an injection (Table). Those with prior PrEP use were more likely to have delayed or missed injections (32%) than those without (21%), with a non-statistically significant odds ratio of 1.78 (95% CI: 0.91, 3.47). Oral bridging was not well documented in EHR; oral PrEP for oral bridging may be prescribed at the start of CAB LA injections but actual use is difficult to ascertain. There was 1 HIV seroconversion concurrent with third injection (all on time); HIV testing at oral PrEP start but not at CAB LA PrEP start. Conclusion: Early adoption of CAB LA for PrEP was successful in OPERA, a US cohort of EHR from routine clinical care. A sizeable proportion of CAB LA PrEP initiators had diagnoses of STI and multiple HIV tests in the preceding 12 months. While 11% of individuals missed an injection, this may be an overestimate of true therapeutic gaps if oral bridging was used.

the early days of CAB LA for PrEP did not align with the CDC testing guidelines among a significant proportion of users.

1111 Drug Level Monitoring for PrEP Users: Feasible and Acceptable, but Is It Necessary? Erica R Pool , Abigail Severn, Jose L. Paredes Sosa, Oliver Stirrup, Claire-Marie Mullender, Marzia Fiorino, Manik Kohli, Irfaan Maan, Rhiannon Owen, Deirdre Sally, Emmi Suonpera, David Dunn, Richard Gilson, John Saunders University College London, London, United Kingdom Background: Good adherence is vital for PrEP efficacy. Most adherence data come from clinical trials but real-world data for long-term PrEP use are lacking. Optimal support for PrEP adherence is not fully established and tenofovir (TFV) drug level monitoring (DLM) could identify those not taking PrEP. It is not known whether DLM would be acceptable to PrEP users or feasible within clinic. Aims: 1. Is PrEP DLM testing acceptable and feasible? 2. Describe adherence in those attending routine care. 3. Compare biochemically verified to reported adherence. Methods: PrEP users aged >18 years attending a large London sexual health clinic were invited to complete a survey on PrEP use and offered a point of care urine test (UrSure®) for TFV. This detects TFV concentration >1000 ng/ mL, consistent with PrEP use in the last 48 hours, validated for emtricitabine tenofovir disoproxil fumarate (F/TDF) and emtricitabine-tenofovir alafenamide fumarate (F/TAF). nonbinary; 70.9% white; 94.8% gay/bisexual; median age 39 years (IQR 30-51). In the last 12 months 37.6% used any recreational drugs and 10.3% used crystal. PrEP use: 71.8% daily, 23.5% event based dosing (EBD); 88.3% F/TDF and 11.7% F/TAF. Median duration of PrEP use was 4 years, (IQR 2-5, range 1-10). Urine DLM was highly acceptable; 79.8% reported that they were quite/very likely to accept it; when offered, 94.3% completed a DLM test. DLM was feasible; median test completion time was 11.4 minutes (IQR 11.2 – 12.5), only 2 invalid results. Reported PrEP adherence matched DLM verified adherence in >95% of cases. Almost all participants had PrEP adherence consistent with efficacy; for 96.7% of daily users adherence was consistent with >4pills/week. For EBD, 73.1% reported >80% of recent condomless sex was covered by PrEP; EBD was often not used with primary partners or partners who are undetectable. Common reasons for missed PrEP were forgetting, running out, busy or not having sex. Conclusion: Point of care PrEP urine DLM was highly acceptable and feasible but in this study did not add to self-reported adherence. PrEP adherence in this population attending for routine care was extremely high despite long-term PrEP use. 1112 A Point-of-Care Urine Test Improves Accuracy of Self-Reported PrEP Adherence Among Women in Uganda Kidist Zewdie 1 , Timothy Muwonge 2 , Timothy Ssebuliba 2 , Felix Bambia 2 , Josephine Badaru 2 , Olivia Nampewo 2 , Gabrielle Stein 1 , Kenneth K. Mugwanya 1 , Katherine K. Thomas 1 , Christina Wyatt 3 , Michael T. Yin 4 , Monica Gandhi 5 , Andrew Mujugira 2 , Renee Heffron 6 1 University of Washington, Seattle, WA, USA, 2 Infectious Disease Institute, Kampala, Uganda, 3 Duke University School of Medicine, Durham, NC, USA, 4 Columbia University, New York, NY, USA, 5 Makerere University–University of California San Francisco Research Collaboration, Kampala, Uganda, 6 University of Alabama at Birmingham, Birmingham, AL, USA Background: Accurate self-reported behavior could facilitate open discussions between providers and PrEP users about HIV risk and effective use of prevention products. We evaluated a recently developed point-of-care urine tenofovir (POC TFV) test to determine whether its use improves the accuracy of self-reported PrEP adherence and influences reported sexual behavior by young African women. Methods: We enrolled sexually active, HIV-negative women ages 16-25 years in Kampala, Uganda. Women were followed quarterly for 24 months with HIV Results: We enrolled 213 people from September 2021-October 2022, 199 completed the survey and DLM test, 14 completed the survey alone. Characteristics of participants were; 94.8% cisgender male; 3.8% trans/

Poster Abstracts

1110 Real-World Use of Cabotegravir Long-Acting for Preexposure Prophylaxis: Trio Health Cohort

Kenneth H Mayer 1 , Andrew J. Frick 2 , Carolyn Brown 3 , Gayathri Sridhar 3 , Leigh Ragone 3 , Jean Van Wyk 4 , Anthony Mills 5 , Steven Santiago 6 , Richard A. Elion 2 , Vani Vannappagari 3 1 Fenway Health, Boston, MA, USA, 2 Trio Health, Inc, Louisville, CO, USA, 3 ViiV Healthcare, Durham, NC, USA, 4 ViiV Healthcare, London, United Kingdom, 5 Men's Health Foundation, Los Angeles, CA, USA, 6 Care Resource Community Health, Inc, Miami, FL, USA Background: Cabotegravir (CAB) long acting (LA) for pre-exposure prophylaxis (PrEP) was approved in the United States in December 2021 to reduce the risk of sexually acquired HIV-1 infection. The Centers for Disease Control and Prevention (CDC) guidelines state that both HIV antigen (Ag)/antibody (Ab) and HIV RNA testing should be conducted at every injection. Real-world testing, effectiveness, and adherence were assessed among individuals initiating CAB LA for PrEP in the US. Methods: Individuals without HIV initiating CAB LA for PrEP were identified from electronic health record data in the Trio Health cohort between December 2021-May 2023. HIV testing and incidence were assessed among individuals with at least one injection of CAB LA. HIV testing was assessed at baseline within 90 days prior to the first injection and during follow-up within ±14 days of injection. Incident HIV was identified with either a positive HIV Ag/Ab lab result with confirmatory HIV RNA test or one detectable HIV RNA. Adherence was assessed among individuals with ≥2 injections of CAB LA. On-time injections were defined as occurring within ±7 days of target date and missed injections were defined as a missed injection cycle. Results: Among the 85 individuals with at least one documented injection of CAB LA for PrEP, the majority were male (93%), White (60%), from the Southern region of US (82%), and the median age was 41 years. Prior to initiation, all individuals had at least one documented HIV Ag/Ab or HIV RNA, and 77% had both tests. During follow-up, 74% of individuals had either HIV Ag/Ab or HIV RNA results at all injections, while 44% had HIV Ag/Ab results, 40% had HIV RNA results, and 20% of individuals had both HIV RNA and HIV Ag/Ab results. No incident HIV diagnoses were identified. Of the 64 individuals with ≥2 injections of CAB LA, 48 (75%) had on-time 2nd injection (Table). Among 43 individuals with ≥3 injections, 27 (63%) had all injections after 2nd on-time. There were no missed injections. 94% continued on CAB LA for PrEP at analysis date. Conclusion: Initial data from Trio cohort suggest CAB LA for PrEP is effective at preventing HIV acquisition. Injections were administered on-time among the majority of individuals. HIV testing practices in this real-world setting during

CROI 2024 360