New Data Link Cabotegravir PrEP to Few HIV Cases, Higher Adherence

Two analyses from the PrEPFACTS study presented at the Academy of Managed Care Pharmacy Nexus 2026 meeting in San Diego, suggest that long-acting injectable cabotegravir (CAB LA) for HIV preexposure prophylaxis (PrEP) was rarely followed by evidence of infection in a large claims database, and that the individuals using it were more likely to have high adherence rates over the first year compared with people taking daily oral PrEP.^1,2 The FDA approved CAB LA for HIV PrEP in December 2021.³

Adherence is central to PrEP’s value, as people who have consistently high adherence are shown to have a significantly lower risk of acquiring HIV compared with those with minimal or declining adherence.^4-6 In addition, partial adherence has the potential to result in subtherapeutic drug levels that could select for drug-resistant viruses. Both analyses used the retrospective PrEPFACTS cohort using data from the Komodo Research Database.

HIV Testing and Evidence of HIV¹

An earlier PrEPFACTS analysis from these same authors covered December 1, 2020, through September 30, 2023. This new analysis extends to data through September 30, 2024. The study population comprised 2913 individuals 12 years and older who received at least 1 CAB LA injection, had at least 12 months of continuous insurance eligibility before their first injection, and had at least 6 months of continuous insurance eligibility after their first injection. People living with an HIV-1 diagnosis, 60 or more days of non-PrEP antiretroviral therapy (ART) at baseline, or any HIV-2 diagnosis were excluded.

The mean (SD) patient age was 36.6 (11.4) years, 82.4% were male sex assigned by payer, 21.5% were Black or African American, and 31.9% were PrEP naïve. Median (IQR) follow-up was 387 (279-560) days, and most patients has commercial insurance coverage (60%), followed by Medicaid (36%) and Medicare (4%). Women accounted for 16% of the cohort and Balck individuals 21% compared with 10% and 15%, respectively, of the general US population taking PrEP.⁷

Testing for HIV was seen following 61.3% of all injections. Broken down, this equates to 65.7% of initiation-phase injections (injections 1 and 2, with a 7-day grace period for HIV testing) and 59.2% of continuation-phase injections (injection 3 and later, with a 28-day grace period for account for delayed claims). The authors concluded that observed testing “did not fully conform to the CAB LA product label or clinical guidelines,” while noting that the database cannot capture tests that were not billed.

Five of the 2913 study population had evidence of HIV-1 during follow-up, which the authors defined as an HIV diagnosis code plus at least 60 days of oral ART available. All 5 started integrase inhibitor–based ART. Three of these cases were previously reported, and the 2 new cases had discontinued CAB LA 15 months and 5 months before their first positive test result. The remaining 2908 individuals showed no evidence of HIV.

Individuals were also able to move between prevention options during follow-up. Of the 2913 people studied, 1056 switched from oral PrEP to CAB LA, and 62% were still using CAB LA.

Adherence Trajectories²

The investigators for this second poster asked whether adherence patterns over time differed by PrEP type, and they carried out 2 comparisons to do so. They compared 440 CAB LA users with 25,646 oral PrEP users and 450 CAB LA users with 13,716 emtricitabine/tenofovir alafenamide (FTC/TAF) users. Oral PrEP overall included generic or branded tenofovir disoproxil fumarate/emtricitabine and FTC/TAF. All study participants were first-time PrEP initiators whose first CAB LA injection or oral PrEP fill (the index date) fell between December 2021 and October 2023, had at least 12 months of continuous insurance eligibility before and after the index date, and no baseline PrEP use in the year before the index date.

Before weighting, CAB LA users had a mean ages of 35.2 (12.2) years vs 36.5 (12.3) years for oral PrEP overall. These participants also were more often female (31% vs 7%) and Black or African American (26% vs 12%).

The investigators measured proportion of days covered in 2-month intervals across that first year, then used latent class growth analysis to identify 4 trajectories: rapid decline (coverage fell off early), delayed decline (coverage remained high for several months before dropping), steady moderate (coverage held at a moderate level), and sustained high (coverage stayed high throughout). Standardized mortality ratio weighting balanced baseline characteristics between cohorts.

After weighting, 40% of CAB LA users followed a sustained-high trajectory compared with 26% of oral PrEP uers overall (probability ratio [PR], 1.51; 95% CI, 1.23-1.85; P < .01). Against FTC/TAF, these figures were 39% vs 25% (PR, 1.51; 95% CI, 1.23-1.85; P < .01). CAB LA users were also less likely to follow a rapid-decline trajectory, at 34% vs 43% for oral PrEP overall (PR, 0.80; 95% CI, 0.67-0.95; P = .01) and 34% vs 46% for FTC/TAF (PR, 0.76; 95% CI, 0.64-0.90; P < .01), as well as to follow a steady-moderate trajectory: 9% vs 18% (PR, 0.53; 95% CI, 0.37-0.77; P < .01) and 10% vs 17% (PR, 0.63; 95% CI, 0.44-0.91; P = .01), respectively.

The delayed-decline trajectory did not differ significantly: 18% vs 13% for oral PrEP (PR, 1.32; 95% CI, 0.95-1.82; P = .10) and 18% vs 12% for FTC/TAF (PR, 1.33; 95% CI, 0.96-1.84; P = .08).

The authors concluded that CAB LA “may allow more individuals to sustain high adherence.”

References

1. Martinez D, Ramirez-Ruiz LE, Nguyen C, et al. Human immunodeficiency virus (HIV) testing and evidence of HIV among real-world long-acting pre-exposure prophylaxis (PrEP) users in a United States claims database: updated results from the PrEPFACTS study. Presented at: AMCP Nexus; October 26-29, 2026; San Diego, CA. Poster 304.
2. Metzner AA, Nguyen C, Alinezhad F, et al. Real world adherence trajectories of cabotegravir long-acting and oral PrEP in the United States: a latent class growth analysis from the PrEPFACTS study using healthcare administrative claims data. Presented at: AMCP Nexus; October 26-29, 2026; San Diego, CA. Poster 310.
3. AJMC staff. FDA approves long-acting, injectable cabotegravir to prevent HIV. AJMC^®. December 24, 2021. Accessed October 28, 2026. https://www.ajmc.com/view/fda-approves-long-acting-injectable-cabotegravir-to-prevent-hiv
4. Gibas KM, van den Berg P, Powell VE, Krakower DS. Drug resistance during HIV pre-exposure prophylaxis. Drugs. 2019;79(6):609-619. doi:10.1007/s40265-019-01108-x
5. Murchu EO, Marshall L, Teljeur C, et al. Oral pre-exposure prophylaxis (PrEP) to prevent HIV: a systematic review and meta-analysis of clinical effectiveness, safety, adherence and risk compensation in all populations. BMJ Open. 2022;12(5):e048478. doi:10.1136/bmjopen-2020-048478
6. Unigwe IF, Goodin A, Lo-Ciganic WH, Cook RL, Janelle J, Park H. Trajectories of adherence to oral pre-exposure prophylaxis and risks of HIV and sexually transmitted infections. Open Forum Infect Dis. 2024;11(10):ofae569. doi:10.1093/ofid/ofae569
7. Deeper look: PrEP. AIDSVu. Accessed October 28, 2026. https://aidsvu.org/resources/deeper-look/prep/