Anso Thom

Health-e News Service

HIV clinicians have welcomed an announcement that the Food and Drug Administration (FDA) in the US has approved the use of an anti-retroviral by sexually active HIV-negative men and women as a method of reducing the risk of HIV infection in adults.

The FDA announced this week that it had approved the use of tenofovir disproxil fumarate/emtricibatine (TDF/FTC), also known as Truvada, in HIV prevention.

TDF/FTC has been used to treat HIV infection since 2004, in combination with other antiretroviral drugs.

The FDA announcement means the pill can be taken by uninfected men and women a day before and after exposure (know as pre-exposure prophylaxis, or PrEP).

Dr Francesca Conradie, president of the Southern African HIV Clinicians Society, welcomed the announcement.

She said there was no one single answer to the prevention of HIV infection, no “one size fits all”.

“However, we would like to stress that the efficacy of Truvada is linked to adherence. The risks of taking this medication erratically are great. Like the use of condoms, consistent use to prevent infection is mandatory. Should infection occur because the person is not taking medication daily, there is a risk of the development of resistance. It is very important that both health-care workers and individuals who want to take this medication be aware of this. It is really an all or nothing regimen,” she said.

The US drug regulatory authority stressed that TDF/FTC should be used “in combination with safer sex practices to prevent sexually acquired HIV infection in adults at high risk” and stressed that the drug was not a substitute for safer sex practices.

The FDA announcement came two months after an independent scientific advisory committee overwhelmingly recommended the use of TDF/FTC for PrEP and a week after the New England Journal of Medicine published two studies showing that the drug reduced the risk of HIV infection among heterosexual men and women in Africa.

The approval paves the way for the drug to be introduced as HIV prevention in the US.

“This is a watershed moment for both US and global HIV prevention efforts,” said Mitchell Warren, executive director of Avac (formerly the Aids Vaccine Advocacy Coalition).

“This is the first completely new biomedical HIV prevention tool to receive FDA approval in 19 years. Importantly, PrEP is a user-controlled method that greatly reduces HIV risk and does not need to be used immediately before or during sex.

“It has the potential to be a powerful tool for many individuals and couples struggling to remain HIV-free.

“Daily oral PrEP using TDF/FTC is absolutely not a silver bullet. It provides partial protection and is not a replacement for other prevention strategies like the male and female condom.

“However, with its decision, the FDA followed the evidence from multiple trials worldwide. This evidence is clear: If you perceive yourself to be at risk, if you take your pill daily, and if you receive the drug as part of a comprehensive package of HIV prevention interventions and testing, oral PrEP using TDF/FTC can dramatically reduce your chances of becoming infected.”

Professor Salim Abdool Karim, Medical Research Council president and director of Centre for the Aids Programme of Research in SA, supports the use of PrEP.

He believes that young African women are the most vulnerable and are most at risk, and that PrEP provides the best HIV-prevention option specifically for this group, who are often unable to negotiate condom use or mutual monogamy.

Karim recently wrote in the New England Journal of Medicine: “Widespread implementation of PrEP is, however, not without challenges that will require additional financial resources and health services capacity.

“Nevertheless, PrEP is an essential new HIV-prevention strategy that can and should be implemented in combination with the use of condoms, HIV testing, and promotion of treatments for HIV infection.

“PrEP prevents HIV infection, thereby reducing the need for treatment of Aids in the future, is cost-effective, and empowers vulnerable populations to directly control their risk of HIV infection.”

World-renowned HIV prevention expert Professor Glenda Gray was more cautious.

Gray said that in SA, approximately 1.8 million people had initiated antiretroviral therapy, representing 55 percent of the people who required this therapy.

“First-line therapy now includes TDF, at a cost of $11 billion (R90bn). The implementation of antiretroviral therapy in SA has been further stressed by the increase in the threshold for initiating treatment to a CD4 count of 350 cells per cubic millimetre.

“In addition, the frequent lack of availability of antiretroviral drugs suggests that existing antiretroviral treatment programmes are already overwhelmed. Until robust concordant trial data are available to guide the complexity of practice here, we should not grasp at straws.

“Giving effective antiretroviral treatment to HIV-infected persons earlier and enhancing the use of proven strategies should be the current mainstays for preventing HIV transmission,” she wrote.