The debate over whether the FDA should approve an existing AIDS medication for preventing the spread of HIV has ratcheted up as more than a dozen advocacy groups are urging the agency to accelerate its review process and not wait for data about heterosexuals. The move comes just one month after one prominent advocacy group urged the FDA not to approve Truvada, which is sold by Gilead Sciences, for prevention, or as pre-exposure prophylaxis, for any group.

In a letter to the FDA and Gilead, the groups say that approval is needed as soon as possible in order to provide protection to gay and bisexual men and transgender women. And they cited data from a study released last November that found that men and transgender women who have sex with men and received a daily dose of Truvada, along with condoms and safe sex counseling, had an average of 42 percent fewer HIV infections than those who received only condoms and counseling (read here).

In fact, three PrEP trials have shown evidence that using Truvada or Gilead’s Viread, which is a component of Truvada, reduced the risk of infections. The other trials examined use by heterosexual men and women, and a so-called partners trial that looked at couples in which one partner is HIV-negative and the other is HIV-positive.But the advoacy groups complain that before results of the heterosexual study were released, the FDA and Gilead were believed to be ready to proceed with a review of PrEP for men who have sex with men, or MSM. And to them, delay means more infections.

“We desperately need new strategies and tools to reduce the rapidly increasing rates of HIV infection in black gay and bisexual men,” Phill Wilson, executive director of the Black AIDS Institute, says in a statement. “We’ve had evidence of PrEP’s effectiveness in MSM for almost a year now. It’s time to use every tool at our disposal to reduce the 50,000 new HIV infections that occur each year in this country. Prompt FDA review will help ensure that appropriate guidelines for PrEP use are established that can reduce HIV infections and safeguard public health” (here is the letter to the FDA and Gilead).

A spokeswoman for AVAC, one of the advocacy groups, noted that the FDA and Gilead are holding talks about the sort of data that may be required. An FDA spokeswoman declined to comment because an application for marketing approval is pending. And a Gilead spokeswoman wrote us to say only that the drugmaker plans to file a supplemental New Drug Application with the FDA for the approval of a once-daily dosage of Truvada for pre-exposure prophylaxis by the first quarter of 2012.

Why might there be a combined review that examines evidence for all populations? Robert Reinhard, an AVAC consultant, suggests the FDA may find it more efficient to conduct such a review because it lessens the “administrative burden” of evaluating complex data. This approach, he adds, may also be perceived by agency officials as more efficient when it comes time to educating physicians and the public about the use of the medicine for prevention. But he argues that so-called sequential approval for different populations would better serve public health than waiting to assess heterosexual data.

The plea for speedier approval reveals a rift among AIDS activists in their approach toward combating the virus. Last month, the AIDS Healthcare Foundation began an aggressive publicity campaign aimed at urging the FDA and Gilead not to proceed with plans to approve Truvada for PrEP for any population. The concern is that using Truvada for prevention will unintentionally lead to riskier sexual behavior and, subsequently, more HIV infections. AHF also argues the lack of real-world data may be misleading about the extent to which sexual practices will play out if Truvada is used for prevention.

In making this argument, AHF has also raised an issue about the extent to which using AIDS medications for prevention is ethical in light of the difficulties many HIV-infected people have currently in obtaining AIDS medications. Many state AIDS Drug Assistance Programs have long waiting lists. (see here and here).

However, AVAC’s Reinhard maintains that this is not a zero-sum game. “We do not think prevention and treatment should be placed in competition because both are needed,” he writes us. “Just as people do not decide to withhold statins or cancer risk reduction resources because resources should be spent to combat heart disease or cancer treatment.”