Gilead Sciences Inc. said Monday that, at the recommendation of the Food and Drug Administration, it will double the length of its late-stage study of HIV drug candidate elvitegravir to almost two years.
Gilead said the study, which compares elvitegravir to Merck & Co.'s drug Isentress, will now last 96 weeks instead of 48 weeks. In a filing with the Securities and Exchange Commission, Gilead said the extension will allow it to collect longer-term safety and effectiveness data.
Gilead said the extension will not affect trials of its four-drug "quad" cocktail. That cocktail combines the drug candidates elvitegravir and cobicstat, along with its already-approved Truvada therapy, into a single tablet.
Shares of Gilead Sciences fell 17 cents to $37.33 in morning trading.