Truvada, a HIV drug developed by Gilead Sciences (NASDAQ:GILD), was shown to decrease the risk of HIV infections by 44%, according to an article published in the New England Journal of Medicine, a significant finding in the path to find alternative ways to prevent AIDS.

While early, the study could provide a financial boost for Gilead, which submitted an application to the Food and Drug Administration for the already-available Truvada to market it as a once-daily HIV antiretroviral treatment.

According to the article, gay men who took Truvada were 44% less likely to get infected by the HIV virus when compared to placebo based on a study of 2,499 patients. Of the men who did get infected, a large majority of them were not taking Truvada as directed.

Gilead’s Truvada is a combination of two antiretroviral drugs – tenofovir and emtricitabine  -- and is currently available for prescription in many countries including the U.S. It’s also one of California-based Gilead’s best-selling drugs, doing $2 billion in sales a year.

If further studies are shown that Truvada can prevent HIV infections, it would provide “another arrow in the quiver” for health officials in the 30-year fight against HIV, as one doctor wrote. The study also only focused on men who have sex with men, and has not been studied in heterosexuals.

Truvada based on this study provides protection against HIV in situations where condoms may not be available.

But the drug comes at a cost. In the U.S., Truvada treatments can run as much as $14,000 a year. Generic versions are available for a fraction of the cost.

Shares of Gilead were down 0.9% on Tuesday to $37.34 a share, along with the broader market.

A link to the Journal's study can be found here: http://www.nejm.org/doi/full/10.1056/NEJMoa1011205#t=article