Feb. 28 (Bloomberg) -- Gilead Sciences Inc.’s Truvada topped Time magazine’s list of medical breakthroughs for 2010 after a study showed it may achieve a goal pursued by scientists for a quarter-century: a pill to prevent HIV infection.
Three months later, the advance has hit a wall. While study findings show the drug prevents HIV in non-infected, sexually active gay men, doctors say they’re wary about giving healthy people a $12,000-a-year medicine that has side effects including nausea and kidney damage, and may not be used as regularly as needed. They also say they’re not often asked to make the drug available for that use.
“We’re not seeing people beating down the doors,” said Kenneth Mayer, medical research director and co-chair of The Fenway Institute, a clinic that serves 15,000 people in Boston, including several thousand gay men. While a few patients have asked about using Truvada for prevention, perhaps for their healthy partners, Mayer says he doesn’t know any clinic doctor who has prescribed it that way.
The issue is central this week at the Conference on Retroviruses and Opportunistic Infections, or CROI, a meeting for AIDS doctors that began yesterday in Boston. A dozen presentations are scheduled that will examine Truvada’s long-term use in uninfected people, its side effects and safety, the best candidates for it and the potential risk of developing drug-resistance with inconsistent use.
“The study was beautifully done and the data are powerful, but, so far, it raises more questions than it answers,” said Martin Markowitz, clinical director of the Aaron Diamond AIDS Research Center in New York City. “People who can’t use a condom, are they likely to take a pill every day?” he asked. “And in the real world, who will pay?”
Healthy men who took Truvada regularly and had detectable levels in their blood were 92 percent less likely to get the AIDS-causing virus than those who took the drug sporadically or received a placebo, according to a study published in the New England Journal of Medicine in November.
Overall the research found the medicine cut infection risk by 44 percent in 2,500 gay men who were prescribed it preemptively for one to three years.
Truvada combines Viread and Emtriva, two drugs made by Foster City, California-based Gilead, into a single blue pill. It’s been used since 2004 to reduce levels of HIV in people infected with the AIDS-causing virus. Researchers in the study theorized that Truvada, taken preemptively, may prevent HIV from gaining a foothold when it first enters the body, averting infection that requires a lifetime of treatment.
Second Biggest Product
The medicine was Gilead’s second-best selling product last year with $2.6 billion in revenue. The company plans to file for U.S. approval as a preventative in the first half of 2011, said Chief Executive Officer John C. Martin in the company’s Jan. 25 earnings call.
In November, soon after the study was reported, Robyn Karnauskas, a Deutsche Bank Securities analyst in New York, said the finding may add $1 billion to Truvada’s sales. The shares in 2011 have risen 7.6 percent before today, compared with the S&P 500 Pharmaceutical Index, which has been little changed.
Use of the drug, though, has increased only slightly, according to data compiled by Bloomberg.
Between 6,805 and 8,107 new prescriptions were written each week for Truvada from December 1, 2010, to Feb. 19, generating $8.7 million to $10.3 million in sales, the data shows. That’s a rise from 5,819 to 7,698 prescriptions, with sales of $6.9 million to $9.2 million, during the same period a year earlier.
‘Giant Question Mark’
“In terms of the market potential, it’s a giant question mark,” said Joshua Schimmer, an analyst at Leerink Swann & Co. in New York, in a telephone interview. “It’s essentially a pipeline product of unknown value. A whole lot of data needs to be filled in before we know how big this could be.”
Gilead fell 3 cents, or less than one percent, to $38.98 at 4 p.m. New York time in Nasdaq Stock Market composite trading.
Gilead spokeswoman Amy Flood said in a telephone interview the company can’t track sales of Truvada for prevention.
During the earnings call, Martin said Gilead doesn’t view Truvada’s new use as a “significant commercial opportunity.” Nonetheless, he said, the company does “see it as an important contribution to management of the HIV epidemic worldwide.”
Karnauskas said she based her estimate on the assumption that 5 percent of uninfected gay men would take the drug 30 percent of the time. That isn’t happening yet, Mayer said in a telephone interview.
“Knowledge of prevention isn’t uniform, not everyone understands the results and there is still some stigma associated with anti-retroviral drugs,” he said.
The AIDS meeting this week in Boston will also explore the use of other preventatives, which may be used in connection with Truvada in some populations, said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which funded the Truvada study.
There are several methods to reduce the chances of HIV infection, including condoms, circumcision and clean needles for intravenous drug users. Progress is being made with other approaches, including topical gels and other drug regimens that will be also reported on at this week’s AIDS conference.
They will likely be used together in different combinations for groups at high-risk for HIV infection, Fauci said in a telephone interview.
“We are starting to become more and more aware that prevention of HIV is not going to be a uni-dimensional phenomenon,” Fauci said. “It’s almost certainly going to be a combination of things that together will have a major impact.”
Researchers are also looking at which population might best be helped by use of Truvada as a preventative. The study results apply only to men who have sex with men. Added trials in intravenous drug users and heterosexuals will be complete starting later this year.
The most likely to benefit, doctors say, may be those who can’t be guaranteed safe sex protection including condoms, or those who don’t wish to use one. That might include prostitutes in some areas, or the partners of people who already have AIDS.
Most new infections in New York City involve young people, often minorities, who can’t afford the $35 per pill price for a drug that must be taken daily, Markowitz said.
Government programs for poor and unemployed people already infected with HIV have waiting lists topping 6,700 people, according to the National Alliance of State & Territorial AIDS Directors in Washington, D.C.
A prevention approach similar to a morning-after pill may have been a better approach, potentially easing problems of cost, long-term risk and the challenge of taking a daily drug, said Kevin Robert Frost, chief executive officer of the New York-based Foundation for AIDS Research. It’s unclear how much benefit the study will yield in the real world, he said.
“This may be the most important scientific breakthrough we’ve had so far to date that we don’t know what to do with,” Frost said in a telephone interview. “At the end of the day this study may prove valuable for the proof of concept that it represents and not for any specific application.”
International health organizations like the World Health Organization and UNAIDS, are now discussing how the approach known as pre-exposure prophylaxis, or PrEP, should be used globally, said Robert Grant, lead researcher in the Truvada study and associate professor of medicine at the Gladstone Institute of Virology and Immunology at the University of California in San Francisco.
The Centers for Disease Control and Prevention is convening panels of experts to discuss how to best roll out wider use of Truvada as a preventative, a strategy they refer to as PrEP. The National Institutes of Health and the Department of Health and Human Services are considering demonstration projects that would establish clinics or programs to offer the pill to high-risk, uninfected men.
Grant said more research is needed to find ways to ensure people take the medicine regularly. Only about half those in the study used the drug consistently, and those who didn’t received no protection. Situations in which one partner is HIV positive and the other is not may benefit most, he said.
“In principle, people are thrilled that there are new concepts available,” Grant said. “We need to let them have time to find out how to best use it.”
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