It wasn’t until 100 women became infected with HIV that UNAIDS and Miami-based Columbia Laboratories decided it was time to end a study that, ironically, was looking at a possible way to block transmission. Researchers had hoped that Advantage-S, a topical gel that contains nonoxynol-9 and is currently sold as a spermicide, would stop HIV in its tracks. In the Phase III study, which involved 700 prostitutes and was conducted in South Africa, Thailand, Ivory Coast and Benin, women were given either Advantage-S or a placebo and, according to Columbia Labs, encouraged to use condoms. Researchers were shocked when those who received placebo—the vaginal cream Replens—showed a slightly lower rate of HIV transmission than those using Advantage-S.

The Advantage-S trial’s design raised ethical red flags for selecting possibly illiterate women from developing countries. “The reality is, if you are going to help these women, you have to conduct the tests on them,” William Bologna, Columbia’s chair and CEO, told The Wall Street Journal in June. “Mary Jane in Toledo, Ohio, is not at high risk for the transfer of HIV. It’s these poor women in Africa.”

The trial has also launched a legal battle. Columbia Labs’ shareholders filed a suit just days after the announcement, arguing that the company misled them when they released preliminary data from the trial that suggested promising results. So what’s next? According to Dominique De Santis, a UNAIDS spokesperson, the future of microbicides still looks bright: “There are other products out there that are in large-scale clinical trials. We must not give up hope.”