FOSTER CITY, Calif. ( TheStreet) -- Gilead Sciences (GILD - Get Report) will start phase III studies next year with a second-generation version of its core HIV drug Viread, the company said Wednesday.
The new HIV drug GS-7340 -- nicknamed "Son of Viread" by investors -- is an important component in Gilead's strategy to extend the life of its HIV franchise through the expiration of Viread patents starting in 2018.
GS-7340 is designed to better deliver tenofivir, the active ingredient in Viread, while also reducing kidney toxicity and other side effects. Best yet, patents on GS-7340 extend out to 2025 in the U.S. and 2027 in Europe.
In addition to patent expiration concerns, Gilead's market-leading HIV franchise faces a threat from dolutegravir, a new but still expiremental HIV drug being developed by GlaxoSmithKline (GSK - Get Report), Pfizer (PFE - Get Report) and Shionogi.On Wednesday, Gilead announced results from a mid-stage study that compared the efficacy and safety of GS-7340 and Viread as part of a single-pill combination regimen. Efficacy was similar after 24 weeks, with 87% of patients on the GS-7340 regimen achieving a viral load response compared to 90% of patients treated with Viread regimen.