Glaxo-Pfizer HIV Drug Helps Hard-to-Treat Patients

An experimental treatment for HIV developed by GlaxoSmithKline Plc (GSK), Pfizer Inc. (PFE) and Shionogi & Co. (4507) reduced the virus in hard-to-treat patients in a late-stage study, providing further support for a regulatory filing by the end of this year.

After 24 weeks on dolutegravir, 63 percent of 183 participants who had shown resistance to previous treatments had undetectable levels of the virus, the drugmakers’ HIV joint venture ViiV Healthcare Ltd. said in a statement today.

The study, dubbed Viking-3, is the third of four late-stage trials to be reported this year that Glaxo plans to use in filing for regulatory clearance of dolutegravir. If approved, dolutegravir would be the second, behind Merck & Co.’s raltegravir, in a new class of HIV medicines called integrase inhibitors that work by blocking the virus’s ability to replicate.

“Viking-3 was designed to address a significant medical need in one of the most difficult populations to treat,” John Pottage, chief scientific and medical officer of ViiV, said in the statement. “We are encouraged by these results.”

In the first of the four late-stage trials, Glaxo said in April that dolutegravir suppressed the HIV virus in 88 percent of study participants, compared with Merck’s raltegravir, which quelled the disease in 85 percent of the group.

In the second study, 88 percent of patients receiving a combination of dolutegravir and two other drugs had undetectable levels of virus in their blood, compared with 81 percent of those getting Gilead Science Inc.’s Atripla, the world’s best- selling AIDS medicine

To contact the reporter on this story: Makiko Kitamura in London at mkitamura1@bloomberg.net

To contact the editor responsible for this story: Phil Serafino at pserafino@bloomberg.net