Study: Drug made in Bay Area stops spread of HIV among gay men

FOSTER CITY, Calif. (KGO) -- A drug developed in the Bay Area is showing that it works in preventing HIV from spreading, according to a new study.

RELATED: Girl's HIV infection seems under control without AIDS drugs

Research with the Kirby Institute found that no new cases of HIV developed in a study of more than 350 gay male couples having unprotected sex.

Those couples include one partner who has tested positive for HIV and another who is negative.

The HIV-negative partners used the drug called Pre-Exposure Prophylaxis or PREP.

It's also called Truvada.

Foster City-based Gilead is the manufacturer.

To learn more about PREP click here.