The topic is politically and socially sensitive, but there's little debate that anal intercourse between men is a major method of HIV transmission.
To address that reality, a University of Pittsburgh researcher has received two National Institutes of Health grants totaling $17.5 million to lead a multidisciplinary research team in development of a microbicidal rectal gel to prevent or reduce HIV infections and determine whether gay men aged 18 to 30 will use such preventive measures.
Dr. Ian McGowan, a University of Pittsburgh School of Medicine professor of medicine in obstetrics, gynecology and reproductive sciences and investigator at the Magee-Womens Research Institute, is principal investigator for both studies.
Collaborating research centers include the University of California, Los Angeles; Johns Hopkins University; the University of North Carolina; and CONRAD, a program of Eastern Virginia Medical Schools that receives U.S. Agency for International Development support.
"The NIH grants really position Pittsburgh as a world center for HIV microbicide research," Dr. McGowan said, noting several other HIV microbicide projects under way in the city.
The five-year $11 million Combination HIV Antiretroviral Rectal Microbicide program, or CHARM, will use existing but yet-to-be-licensed HIV microbicides (agents that kill the microscopic virus) in a topical preparation designed to be applied to the rectum to prevent HIV infection.
For the last 20 years, HIV microbicides have been created for vaginal use, including research under way at the University of Pittsburgh Graduate School of Public Health and the Microbicide Trials Network based at Magee-Womens Research Institute, where laboratory studies are focused mostly on providing women a means to protect themselves against HIV infection.
But Dr. McGowan said his study will focus on safe and effective microbicides for the rectum, which poses challenges. The rectal lining, or epithelium, is only one cell thick, as compared with the vaginal epithelium that's 20 cells thick. That makes the rectum more vulnerable to fissures and tears during anal intercourse, allowing HIV easier access to the body.
Once developed, the microbicidal gel will be used in animal trials, then if successful, proceed to a human clinical trial involving 12 to 18 gay men to study its safety and efficacy. Dr. McGown said he hopes human studies will begin within the first two years of the five-year grant.
He's also working with Alex Carballo-Dieguez of Columbia University in a four-year $6.5 million project, "Microbicide Safety and Acceptability in Young Men," to examine how willingly men will use such gels to prevent infection. From a group of 240 young gay men, 40 men eventually will be selected based on their willingness to use a placebo gel properly. They also will undergo counseling in safe sexual practices and be provided with condoms.
The 40 men then will participate in a two-week trial to study the safety of the actual microbicidal gel.
Dr. McGowan said the size of the NIH grants reflects a change in Washington, D.C., where the Obama administration has shown greater interest in funding HIV-prevention research.
"The Bush administration had a very high level of discomfort embracing HIV prevention research in men," he said. "But I think in the Obama administration that's a non-issue. They regard domestic HIV prevention in men who have sex with men as an important research priority."
It also reflects growing awareness that not only men have anal sex.
"There's increasing evidence that men and women have anal sex, too," he said. "If we are interested in HIV prevention, we have to look at options for both men and women."
David Templeton can be reached at email@example.com or 412-263-1578.