Gilead (GILD) is out Monday with a dense press release showing comparative Phase 3 studies of two approved TAF-based combos.
Quickly, GILD showed that patients on TDF-based Truvada can be safely switched to TAF-based Descovy while staying on their third, separate drug to control the disease. Renal and bone parameters were improved.
Two studies were performed using Odefsey, the 3-drug combo using the drugs in Descovy plus J&J's (JNJ) rilpivirine, called Edurant when given solo. One was a switch study against Complera; the other was a switch study against Atripla. The switch study against Complera was fine, with no change in viral control and improvements in bone and kidney parameters. The switch study against Atripla showed marginally worse control of the disease (90% versus 92%), which could have been a random effect. In that latter study, apparently kidney function as measured by GFR was not improved while on Odefsey. So I'm not sure how successful that study, #1160, was. Atripla has fallen out of some favor by certain experts.
Odefsey is already approved by the FDA for switching, such as from Complera. Descovy is not labeled for switching, though I'm sure it's going on. GILD's press release did not mention whether GILD is planning to file to have the label specifically allow switching.
GILD has also previously said that it is in discussions with the FDA about a study for Descovy as PrEP.
Most of the results discussed were positive. We'll learn more in this and upcoming earnings releases and conference calls about how well TAF-based combos are faring in the marketplace against TDF-based ones. Certainly the company has sounded happy with the success at least of Genvoya as an improvement on Stribild.
Nothing in this press release likely moves any EPS needles for the stock to an important degree.