A daily pill helped protect gay and bisexual men from catching HIV in a study, the first to show that a drug used to treat the world’s deadliest virus can also be used to prevent it.
Gilead Sciences Inc.’s Truvada, sold since 2004 to subdue HIV in infected people, cut the risk of contracting the AIDS- causing virus by 44 percent, and reduced new infections as much as 73 percent in those who used it most, according to results published yesterday in the New England Journal of Medicine. The findings may boost annual revenue for Gilead, the world’s largest maker of AIDS treatments, by $1 billion.
The study is the third prevention trial in 14 months to raise hope that HIV can be defeated after decades of failed efforts to develop a vaccine. The U.S. Centers for Disease Control and Prevention, anticipating that some men will ask for the drug immediately, warned that condoms remain the best way to avoid infection and Truvada isn’t approved for that use.
“There will be more people walking into doctor’s offices saying, ‘Wow, these data look impressive, would you write me a prescription?’” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said at a briefing.
The researchers followed 2,499 HIV-negative men aged 18 to 67 in Peru, Ecuador, South Africa, Brazil, Thailand and the U.S. who were all HIV-negative at the start of the study. Each participant was followed for a median of 1.2 years.
As many as eight more studies are evaluating the safety and efficacy of using the same approach to prevent infections in heterosexuals and injecting drug users.
End In Sight
“The end of AIDS is no longer a dream, it’s in sight,” Mitchell Warren, executive director of the New York-based AIDS Vaccine Advocacy Coalition, said in an interview. “We have tools that when combined are going to allow us to break the back of the epidemic.”
AIDS killed about 1.8 million people globally in 2009, the Joint United Nations Programme on HIV/AIDS, or UNAIDS, said in a report yesterday. That makes HIV the deadliest infection ahead of tuberculosis and malaria, World Health Organization data show. Gay and bisexual men account for more than half of all new infections in the U.S., according to the Atlanta-based CDC.
Because Truvada is already a licensed treatment, doctors would be able to prescribe it for prevention without regulatory approval. A study published last year in the Journal of Acquired Immune Deficiency Syndromes found that among 277 gay men in Boston, 74 percent said they would use AIDS drugs for prevention if they were available.
“I am encouraged by this announcement of groundbreaking research on HIV prevention,” President Barack Obama said in a statement yesterday. “While more work is needed, these kinds of studies could mark the beginning of a new era in HIV prevention.”
The study “raises a large commercial opportunity for Gilead’s franchise” and may increase Truvada sales by $1 billion eventually, Robyn Karnauskas, an analyst for Deutsche Bank Securities, said yesterday in a note to investors. She based her estimate on the assumption that 5 percent of uninfected gay men would take the drug 30 percent of the time.
Karnauskas said many questions remain “about the validity of prophylactic use in the real world setting,” including the risk that long-term use would damage patients’ kidneys, cause other side effects, or lead to resistance to the drug.
Gilead rose 80 cents, or 2.2 percent, to $37.78 at 4 p.m. New York time in Nasdaq Stock Market composite trading. The stock had declined 21 percent in the 12 months before today.
Truvada combines two Gilead drugs, Viread and Emtriva, in a single pill, and was the Foster City, California-based company’s best-selling product last year, with revenue of $2.5 billion.
Gilead Weighing Options
Gilead doesn’t expect the results to fuel demand immediately for Truvada, said Howard Jaffe, chairman of the Gilead Foundation, the company’s nonprofit charity, and a co-author of the study. Gilead doesn’t track how many people use the drug to stop infections, and hasn’t decided whether to ask the Food and Drug Administration to approve it for prevention, Jaffe said.
“This is a major breakthrough,” Kevin Fenton, director of the CDC’s Center for HIV/AIDS, said in a telephone interview. Still, “it’s not time for gay men to throw out their condoms,” he said.
Trial participants were given condoms, counseling on safe sex, and testing for HIV and other sexually transmitted diseases once a month the men. They also returned their pill bottles to see how diligent they were in taking the drugs.
A total of 100 men contracted HIV during the trial, including 36 on Truvada and 64 of those getting a placebo, translating to a 44 percent reduction in risk.
The result was “a little lower than what we had hoped for, but nonetheless very encouraging,” said Cate Hankins, chief scientific officer at the Geneva-based Joint United Nations Program on HIV/AIDS, or UNAIDS. “It does show that this concept works.”
The drug worked better in men who took it consistently. Among those who took their pills on 90 percent or more of days, the Truvada group had 73 percent fewer infections than the placebo group. Among those who became infected, 91 percent had no detectable drug in their blood, said Robert Grant, an associate professor of medicine at the Gladstone Institute of Virology and Immunology at the University of California in San Francisco. He led the research.
The researchers were concerned that men in the trial may have riskier sex on the assumption the pill was protecting them. Instead, the men said they used condoms more frequently and had fewer partners over the course of the study. No drug resistance was observed among those who became infected.
Nausea, Weight Loss
Men on Truvada had more nausea in the first four weeks of the study, and more of them lost weight unintentionally.
“The number one message that must go out is, don’t try this at home,” Warren said. “This is not the pill you take and all is well. For those people who think, ‘I’m at risk, I want this pill,’ they have to have a conversation with their health provider.”
The study raises questions about whether governments and insurers will pay for AIDS drugs to prevent infections. Truvada costs between $5,000 and $7,000 a year in the U.S. when bought through the health-care system, and more if bought privately, CDC’s Fenton said.
“This is going to be out of the reach of many individuals in the U.S.,” Fenton said. The agency has had preliminary discussions with insurance companies and plans to hold further talks with public and private insurers, he said.
Other research breakthroughs on HIV and AIDS include a study presented in July that showed a vaginal gel containing Gilead’s Viread cut infections by 39 percent among women in South Africa. In September last year, an experimental vaccine cut infections by 31 percent in a trial in Thailand.
Truvada is already used in combination with Bristol-Myers Squibb Co.’s Sustiva to prevent infections in men who take it after unprotected sex with an HIV-positive partner, or in health workers accidentally jabbed with a contaminated needle. The combination pill, called Atripla, is the world’s best-selling AIDS treatment, with $743 million in third-quarter sales.
Gilead separately said yesterday it applied to U.S. regulators for approval of a new combination pill that adds Truvada to Johnson & Johnson’s TMC-278. It would be the world’s second single-pill regimen for HIV, following Atripla, Gilead said. The J&J component is itself under FDA review.
Truvada subdues HIV in infected patients by blocking an enzyme the virus needs to hijack cells in order to reproduce. Researchers in the study hypothesized that, taken preemptively, the pill may prevent HIV from gaining a foothold when it first enters the body.
The trial cost about $43.6 million, of which the National Institute of Allergy and Infectious Diseases contributed $27.8 million and the Bill and Melinda Gates Foundation paid $15.7 million. Gilead donated the drugs used in the trial and paid travel costs for some of the researchers.