Early study results show a good deal of promise for GS 7340, a newer form of tenofovir. The GS 7340 dose is about 10 times less than Viread, it appears to control HIV better, and it may help reduce side effects currently seen with Viread. GS 7340 will also be studied in a single pill regimen (with cobisistat, Prezista and Emtriva) as well as a replacement for Viread in the upcoming Quad pill.
In a small study of 38 people over 10 days, three doses of GS 7340 were given: 8, 25 and 40mg, compared to the regular dose of Viread. CD4 counts averaged 450. Everyone had viral loads >2,000 copies with no signs of resistance.
The researchers looked at how much viral load had decreased on day 11: placebo (0.07 log), Viread (0.97 log), 8mg (1.08 log), 25mg (1.46 log) and 40mg (1.73 log). Also promising were the lower blood concentration of GS 7340 (79% on 25mg and 98% on 40mg) which could mean fewer side effects including less kidney damage, as well as the higher cellular concentration of GS 7340 (20 times higher on 40mg) which could mean longer and more suppressive control of HIV over time.
The company that makes GS 7340 is moving the 25mg dose forward in other study.