By Toni Clarke
BOSTON | Wed Mar 23, 2011:
(Reuters) - Gilead Sciences Inc said on Wednesday that its experimental HIV drug elvitegravir proved as effective as a drug made by Merck & Co in a late-stage clinical trial.
The trial showed that after 48 weeks of treatment, dosed once daily, elvitegravir was as effective as Merck's Isentress, which is dosed twice daily in combination with other antiretroviral drugs.
Gilead's shares rose 2.7 percent to $41.53 in midday trading.
Discontinuation rates caused by adverse events were comparable in both arms of the study, the company said. Gilead plans to submit the data for presentation at a scientific conference later this year.
Elvitegravir is designed to block the ability of the HIV virus to integrate into the genetic material of human cells.
The drug is also part of a four-medicine HIV pill being developed by Gilead known as the "Quad." Last year a mid-stage trial showed the Quad works as well as Gilead's widely used Atripla three-drug tablet.
Atripla combines Emtriva, Viread and Bristol-Myers Squibb Co's Sustiva.
Data from Phase III, or late-stage, Quad trials, which investors are watching closely, are expected beginning in the third quarter of this year.
"We view this as good news for Gilead and believe this data helps de-risk the key Quad Phase IIIs," said Brian Abrahams, an analyst at Wells Fargo, in a research note.
Gilead licensed elvitegravir from Japan Tobacco Inc in March 2005. Gilead has exclusive rights to develop and commercialize the drug everywhere except Japan.
Results of the Phase III elvitegravir trial showed that after 48 weeks of treatment 59 percent of patients taking elvitegravir achieved target reductions in levels of HIV in the blood, known as viral load, compared with 57.8 percent of those who received Isentress, which is also known as raltegravir.