Is an “HIV Prevention Pill” Worth It?

Pre-exposure prophylaxis (PrEP) is an experimental method of HIV prevention. It involves a doctor prescribing antiretroviral HIV/AIDS drugs to a healthy person in order to prevent that person from possibly getting infected with HIV. So far, clinical trials have failed to prove PrEP’s effectiveness… (Click below to read more.)

The 2007 iPrEX study found that PrEP reduced the risk of HIV infection among men who have sex with men (MSM) by only 44%. A part of the 2009 Vaginal and Oral Interventions to Control the Epidemic (VOICE) study was discontinued two years later because tenofovir (branded as Viread by Gilead Sciences) tablets were no better than a placebo in protecting HIV-negative women from HIV. Researchers stopped another trial in 2011, called Fem-PrEP, after they concluded that Truvada (Gilead’s combination tablet of tenofovir DF and emtricitabine) was unlikely to prevent HIV infection in women. Partners PrEP, a study of sero-discordant couples in Africa, showed an efficacy rate of 62%-73%. However it is imprudent to extrapolate the overall effectiveness of PrEP based of this study since the researchers reported an adherence rate of 95% among the study participants — a figure that would likely be much lower under non-clinical trial conditions and as a result, would likely lead to a lower overall efficacy rate.

Questionable clinical efficacy aside, a surge in the interest around PrEP is puzzling given that 14.6 million HIV positive people around the world in need of ART right now are not receiving it. Expanding the permitted use of a lifesaving antiretroviral therapy—which is currently unavailable to those 14.6 million individuals still in need of treatment—as a sanctioned form of HIV prevention for use by uninfected individuals presents both a practical and moral dilemma for both Gilead and society at large.

In the United States, the Centers for Disease Control and the Federal Drug Administration (FDA) have expressed interest in establishing guidelines for the use of PrEP. Under the current regulations, a medical provider is allowed to prescribe ART to a HIV negative person. This is called ‘off-label use’ – use of an HIV/AIDS medication for purposes other than treatment of HIV— effectively constitutes PrEP. However, as long as PrEP is not officially sanctioned by the FDA, drug companies cannot market ARTs as a preventative measure to the public. If PrEP is eventually approved by the FDA, pharmaceutical companies stand to make a lot of money catering to a new market in the developed world instead of providing cheaper—and much needed—drugs in the developing world.

Internationally, PrEP has also received attention from the EU, the World Health Organization and various civil society organizations and advocates in the global health arena. The fact that PrEP is being considered as an evidence-based HIV prevention approach is incomprehensible at a time when the world cannot treat all people with HIV who are already ill.

With the continued assault on generic drug manufacturers by Big Pharma and a stagnating commitment by the rich countries to contribute more money to the global AIDS fight, PrEP looks more like a pharmaceutical cash cow in the making, than a viable or prudent public health initiative. In the United States, one year of ART can cost upwards of $10,000 USD. Currently, there are waiting lists in the US for HIV-positive low-income people in need of treatment. In Eastern Europe, Central Asia and Africa ART coverage remains unacceptably low and far behind the Universal Access target of 80% for all who need it. Is it possible to justify giving PrEP to healthy people while the sick and dying are waiting for treatment?

The legitimization of PrEP is detrimental because it could lead to a false sense of security among people who are currently using condoms to protect themselves. To achieve even a modest level of protection, PrEP requires strict adherence to a daily ART regimen. If we ponder that adherence to ART among HIV-positive patients still remains a challenge in many places and that side effects associated with ART can be severe, the likelihood of an HIV-negative person taking the medication consistently as a preventative measure seems low.

As long as there is no compelling scientific evidence proving that PrEP is effective, the global health community must focus on the things that do work. Global AIDS control lies in finding equilibrium between the prevention of new infections and treatment of people who need lifesaving medication. The HPTN 052 clinical trial proved that ART works as prevention, by lowering infectiousness in HIV positive people by 96%. Condoms, when consistently used have also been shown to be over 90% effective in preventing new infections.

When it comes to prevention of new HIV infections, condoms are by far more cost-effective and reliable than PrEP. However, the global health establishment has come upon numerous political, economic and ideological challenges in trying to promote condom use. Prevention work is tedious and difficult, as evidence by the continuingly growing number of new HIV infections in the world. Perhaps prevention is even more challenging then treatment, which may explain eagerness by some to embrace PrEP despite its questionable effectiveness. Unfortunately, when it comes to prevention there is no magic pill.

Denys Nazarov
Global Policy Coordinator