Formulary Decisions For HIV Prevention: Pre-Exposure Prophylaxis

Since the human immunodeficiency virus (HIV) was first identified in the early 1980s, significant progress has been made in disease treatment and awareness. The development of combination antiretroviral therapy (ART) in 1987 reduced death related to acquired immunodeficiency syndrome (AIDS) by 50%, therefore redefining the prognosis of infected individuals. HIV therapy continues to improve as ART options are expanding and newer agents advertise improved tolerability and efficacy. Despite these advancements, HIV remains a public health concern as over 1.2 million Americans have a HIV diagnosis and only 55% of this population are virally suppressed. Notably, progress for prevention of HIV has been slow-moving worldwide with 1.8 million people newly infected with HIV in 2016, a modest 11% decline since 2010. 

The Joint United Nations Program on HIV/AIDS, known as UNAIDs, has recognized prevention as the cornerstone to achieving their 2030 goal of eradicating AIDs. Earlier this month, the organization published the HIV Prevention 2020 Road Map. This publication addressed traditional methods for primary prevention (eg condoms and behavioral change programs) as well as pre-exposure prophylaxis, or PrEP.

Pre-Exposure Prophylaxis

PrEP has been a popular topic of discussion among health professionals as it is one of the most effective, underutilized approaches in primary prevention of HIV. It is defined as the use of ART in HIV-negative individuals at risk of HIV infection. Patients eligible for PrEP include, but are not limited to, individuals with HIV-positive sexual partners or multiple sexual partners and injectable drug users. Guidelines recommended PrEP therapy consists of once-daily tenofovir disoproxil (TDF) alone or in combination with emtricitabine (FTC). Clinical trials have consistently shown efficacy, safety, and tolerability of PrEP therapy. The CDC reports that consistent use of PrEP reduces the risk of attaining HIV from sexual transmission by more than 90%. Additionally, injectable drug users may reduce their risk of HIV by over 70% with PrEP. 

Alternative dosing schedules for PrEP candidates have been researched in effort to reduce complications of adherence and unnecessary toxicity from long-term ART. A multicenter study conducted in France and Canada, IPERGAY, assessed the efficacy and safety of “on-demand” PrEP in a high-risk population of men having sex with men. Participants were instructed to take two tablets of TDF-FTC or placebo with food 2 to 24 hours prior to sex. An additional tablet was taken 24 hours and 48 hours after the first dose. This treatment schedule was proven effective in the MSM population with an 86% relative reduction in the incidence of HIV-1 acquisition in the TDF-FTC group (P = .002). 

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Although efficacious, PrEP is greatly underutilized. The CDC estimates of 1.2 million Americans having indications for PrEP while only 100,000 patients are prescribed PrEP.  This gap emphasizes the need to eliminate barriers to treatment, which includes cost, stigma, and lack of provider and patient awareness. Teva’s generic formulation of TDF-FTC is not available, but is expected to lower the cost barrier and improve access to PrEP. 

Future of Prevention

The future for HIV prevention is promising with advancements in neutralizing antibody research. Hundreds of naturally produced broadly neutralizing antibodies (bNAbs) have been identified from HIV-positive individuals. These antibodies block strains of HIV and are now being tested for use in both treatment and prevention through development of vaccines and gene therapies. Continued progress could revolutionize HIV management to a simple injection.

Health initiatives such as UNAIDS have a newfound focus on disease prevention due to an unmet need for awareness and treatment. Health care professionals should recognize that PrEP is an underutilized and effective preventative HIV measure that should be available for individuals at high risk of acquiring the virus. 

With a generic alternative coming to market for PrEP and ongoing research of bNAbs, HIV prevention has great opportunities for progress and aiding UNAIDS in its goal of eliminating AIDS/HIV by 2030.