Technology.am (Oct. 3, 2009) — The National Institutes of Health has awarded Albert Einstein College of Medicine a four-year, $7.2 million grant to develop a microbicide-releasing vaginal ring to prevent HIV transmission.
At present, there are several models available for delivering contraceptives, but none for microbicides. The microbicides will be incorporated into vaginal ring under development.
Betsy C. Herold, professor of obstetrics & gynecology and women’s health at Einstein said, “When you expose HIV to a single drug, you make it easier to select for resistance, so, we are trying to target HIV infection at two different steps very early in its life cycle, which should prevent the establishment of any infection.”
One of the drugs to be evaluated is tenofovir, which blocks reverse transcriptase, an enzyme crucial to HIV reproduction. Tenofovir is used currently as an oral systemic therapy against HIV, but it has also shown promise as a topical microbicide.
The team will also test the efficacy of two so-called fusion inhibitors, including maraviroc and PIE12-trimer, which block the virus from entering target immune cells by different mechanisms.
The team will pay particular attention to choosing microbicides that preserve natural vaginal defenses against HIV.
“We want to preserve that protective barrier while adding drugs that will be at the right place at the right time when the virus presents,” says Dr. Herold. “That is why a ring, which can provide sustained delivery of the microbicide over three to four weeks, would be ideal. People wouldn’t have to remember to use it, which is a problem with gels and pills. Also, we don’t know if oral medications will get to the right place – some drugs get into the genital tract well, but some don’t.” The ring could be replaced monthly without a doctor’s supervision.