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By Ben Hirschler
LONDON, Feb 8 (Reuters) - GlaxoSmithKline and GileadSciences will vie for business in treating HIV patientsnext week when both companies unveil clinical trial results at amedical meeting in Seattle.
Most attention is focused on Gilead's next-generation drugbictegravir, a so-called integrase inhibitor similar to GSK'ssuccessful dolutegravir that may offer advantages in terms ofgreater potency and reduced side effects.
GSK plans to defend its patch by highlighting the potentialof a new two-drug treatment regimen for controlling the virusbehind AIDS, a development that marks a departure fromconventional triple drug cocktails.
As dolutegravir has been the mainstay of GSK's HIV businessin recent years, investors are nervous about the threat posed byGilead's competitor, even though next week's bictegravir data isonly from mid-stage Phase II testing. The drug is also in finalstage Phase III testing.
GSK Chief Executive Andrew Witty said dolutegravir's keyattribute was its proven track record in avoiding the HIVvirus's potential to develop drug resistance. He described otherissues as "peripheral".
"It has an extremely impressive resistance profile," Wittytold analysts after reporting fourth-quarter results onWednesday.
"It is not easy to beat ... in terms of the thing thatreally matters, I think that dolutegravir remains an extremelyimpressive molecule."
Results of Gilead's Phase II trial comparing bictegravirwith dolutegravir when both drugs are used as part of adrug-drug combination will be presented at the Conference onRetroviruses and Opportunistic Infections in Seattle on Feb. 13.
Detailed findings from two Phase III trials testing GSK'snew two-drug combination of dolutegravir and Johnson & Johnson's rilpivirine will also be presented the same day. GSKalready said in December that the studies were successful.
GSK sells its HIV drugs through its majority-owned ViiVHealthcare unit, in which Pfizer and Japan's Shionogi hold minority stakes. GSK said Shionogi had made clearit intended to retain its stake in ViiV and its put options hadnow been removed. (Editing by Elaine Hardcastle)
