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PrEP in Africa at HIVR4P
Empowering Prevention: PrEP Innovations for Africa at HIVR4P

Released: November 05, 2024

Expiration: November 04, 2025

Kenneth Ngure
Kenneth Ngure, MPH, MSc, PhD
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Key Takeaways
  • Providing a diverse range of pre-exposure prophylaxis (PrEP) options and formulations for HIV prevention in African countries can increase adherence rates, empower patients with a sense of control, and overcome financial barriers to PrEP.

HIVR4P 2024 highlighted a variety of studies on HIV prevention in Africa, each introducing innovative antiretrovirals designed for use across diverse patient populations. Explore a few of these insightful findings below.

Novel Antiretrovirals and Formulations for PrEP
During HIVR4P, the latest findings from the PURPOSE-2 trial on long-acting (LA) injectable lenacapavir (LEN) for HIV prevention were presented by Dr Colleen Kelley. PURPOSE-2 was a phase III, double-blind, randomized controlled study assessing the effectiveness of twice-yearly LEN for HIV prevention. The study involved 3265 participants in the efficacy analysis, including cisgender men, transgender women, transgender men, and nonbinary individuals who have sex with partners assigned male at birth. I was glad to see that it included people from Argentina, Brazil, Mexico, Peru, South Africa, Thailand, and the United States.

The results revealed that LEN reduced HIV acquisitions by 96% compared to background HIV incidence (primary endpoint) and was superior to daily emtricitabine/tenofovir disoproxil (FTC/TDF) for HIV prevention (secondary endpoint). This establishes LEN as a superior, LA pre-exposure prophylaxis (PrEP) option with the potential to transform HIV prevention, particularly in African regions with high HIV prevalence.

It is especially encouraging that these results were reported in such a diverse participant population and across many different geographic locations. I believe this study highlights the potential global impact of twice-yearly LEN for HIV prevention.

Another phase III study assessed the safety of PrEP with once-monthly oral islatravir (ISL), a nucleoside reverse transcriptase translocation inhibitor (NRTTI), compared to daily FTC/TDF in cisgender women at high risk of HIV-1. The trial was halted early due to observed dose-related reductions in lymphocyte and CD4 counts among ISL users, though participants showed partial recovery in the open-label phase, and no participants contracted HIV during the blinded phase.

Due to these safety concerns, ISL is no longer in development as oral PrEP. However, I think the fact that almost 95% of participants continued throughout the double-blind phase and entered the open-label phase is indicative of a strong interest in, and desire for, more LA PrEP options.

The IPM-054 study was a phase I, open-label, randomized crossover trial assessing the bioavailability of  3-month dapivirine vaginal ring (DVR) compared to a monthly DVR. The trial found that the 3-month DVR provides higher drug levels than the monthly version, indicating that its effectiveness would be at least comparable. This supports the 3-month DVR as a viable alternative, with additional benefits such as reduced cost, waste, and replacement frequency, making it particularly suitable for use in the African region.

The Power of Choice
The CATALYST study evaluated PrEP method choice among women at public health sites in 5 African countries. Between May 2023 and December 2023, 2383 women, including those who were pregnant or breastfeeding, were offered a choice between oral PrEP and a PrEP ring. Oral PrEP was chosen by 61% of participants, 35% opted for the PrEP ring, and 3% declined both.

Among PrEP-naive participants, those involved in sex work, engaging in condomless sex, and having multiple partnerships were more inclined to choose the PrEP ring, indicating that this is an important PrEP option for people who engage in behaviors that put them at higher risk for HIV acquisition.

Preferences for oral PrEP centered on ease of use (50%) and perceived effectiveness (29%), while the PrEP ring was favored for being easy to use (56%) and not requiring pill swallowing (53%). Ultimately, these findings highlight a moderate uptake of the PrEP ring, supporting the value of informed choice within PrEP programs in the African region while also illustrating that more work needs to be done to educate the public on PrEP efficacy and support PrEP initiation.

The SAMURAI study was a 12-month crossover trial conducted in Cape Town and Johannesburg, South Africa. It investigated the acceptability, adherence, and safety of placebo versions of 2 LA PrEP options: bimonthly injections and a 6-month implant. The study focused on cisgender men who have sex with men and men who exclusively have sex with women. The study enrolled 184 men with an 86% retention rate and found that more participants initiated injections (97.8%) than implants (91.3%), though persistence was higher with implants (91.1%) compared to injections (80.6%).

Both methods were rated similarly in satisfaction (8.6 for injections, 8.4 for implants) and likelihood of future use. In terms of preference, nearly equal proportions favored injections (48.4%) and implants (47.7%). Adverse events were minor and unrelated to the products, with a few social harms reported.

As both options were equally acceptable and preferred, this study underscores the value of providing varied PrEP choices to accommodate user preferences and improve persistence, especially among those less familiar with specific delivery methods. I believe that this study shows that men in Africa are open to the possibility of more varied PrEP choices, and that expanding PrEP options can empower people to make the best choice for themselves, thereby improving satisfaction with PrEP and encouraging PrEP persistence.

Your Thoughts?
Which study encompassing HIV prevention in Africa is most impactful? Get involved in the discussion by posting a comment below.