Three Important PrEP Developments Emerge from IAS 2019
by Hank Trout
Three new developments regarding the use of PrEP (pre-exposure prophylactic) worldwide have arisen from the Tenth International AIDS Society (IAS 2019) in Mexico City in July, as reported by NAM/aidsmap.com. These developments have the potential to expand and improve use of PrEP across the planet.
First, the World Health Organization (WHO) has updated its recommendation for the use of PrEP to include event-driven PrEP taken before and after sex, also known as on-demand PrEP or the 2+1+1 schedule, as an HIV prevention option for MSM (men who have sex with men). “Event-driven PrEP” involves taking a double dose (two pills) of Truvada (tenofovir disoproxil fumarate/emtricitabine) between two and 24 hours before sex is anticipated, and then, if sex occurs, one pill 24 hours after the double dose and another 24 hours later. .
The benefits of on-demand PrEP include convenience for gay men who have a high HIV risk for only a brief period (for example, on vacation) or have sex infrequently; a lower burden of pills to take; and lower costs for the user. The on-demand regimen is suitable for men who find intermittent PrEP use more effective and convenient, those who have sex less frequently, and those who can plan for sex at least two hours in advance. But it also carries potential risks. It is not suitable for women or for people with chronic hepatitis B. WHO’s decision was based upon results of the Prevenir study of 3,057 men, thirty of whom identified as heterosexual and thirteen transgender men. Two of those 3,057 men seroconverted; but they had stopped taking PrEP several weeks before and had condomless sex in the interim..
Another important IAS 2019 announcement from WHO involves the ways in which PrEP services can enhance the control of STIs worldwide. Dr Jason Ong of Monash University in Australia conducted a review of STI incidence and prevalence in 88 PrEP studies. He found that STI prevalence was already high in people seeking PrEP, with 24% having chlamydia, gonorrhea, and/or early syphilis. Incidence was extremely high while people were on PrEP: for chlamydia, compared to a global average incidence of around 3%, it was 21% in PrEP users. WHO has outlined a series of interventions needed to address STIs within PrEP programs. Some methods are already available: condoms and lubricants, partner notification services, and culturally sensitive services for specific communities. Since the people who could most benefit from PrEP are also likely to be at increased risk of STIs, PrEP services can be an entry point to comprehensive sexual and reproductive health services, including STI screening and treatment. By the same token, clinics testing and treating STIs should offer PrEP to those who would benefit.
WHO recommends policy and funding changes that are needed. In many lower- and middle-income countries, STI services rely on “syndromic management”—that is, people who have STI symptoms are offered treatment presumed to be correct, without any STI testing. Syndromic management can result in inappropriate or unnecessary treatment being offered, but worst of all, can lead to the massive under-treatment of STIs. This type of syndromic management serves young women particularly poorly, as many vaginal infections are asymptomatic or cause such mild symptoms that adolescents may not recognize as being due to an STI. Services rely on syndromic management because diagnostic assays are prohibitively expensive. .
Perhaps most encouraging for PrEP users, Merck’s Dr. Randolph Matthews announced that an implant containing Islatravir, the latest HIV drug to be added to the ever-growing list of antiretrovirals, inserted under the skin of the upper arm, should provide sustained levels of drug sufficient to prevent HIV infection for over a year. The drug was the subject of one of the most anticipated studies presented at this year’s conference. .
The purpose of the study was to assess the safety and tolerability of the implant, a small plastic insert that is placed under the skin of the upper arm. The Merck implant is not visible to others when implanted, an advantage for people who may fear being seen taking antiretrovirals. It also has the advantage of being removable—it can be taken out in the case of side-effects. Dr. Matthews said that once removed, levels of drug trailed off about as quickly as those of the oral dose.
The insertion of the implant (4 cm by 2 mm) is not totally pain-free. Some study participants reported that the implant insertion initially produced some localized internal bleeding and discomfort; others complained of inflammation or itching in the implant area. But participants reported that these side-effects were “tolerable” and outweighed the costs.
Hank Trout, Senior Editor, edited Drummer, Malebox, and Folsom magazines in the early 1980s. A long-term survivor of HIV/AIDS (diagnosed in 1989), he is a forty-year resident of San Francisco, where he lives with his fiancé Rick. Follow him on Twitter @HankTroutWriter.