* High aspirin does may reduce Brilinta efficacy
* Finding raises more questions about drug’s use in U.S.
LONDON, Oct 29 (Reuters) - The discovery that AstraZeneca’s (AZN.L) new blood thinner Brilinta may be less effective when patients get a high dose of aspirin has rekindled concern about prospects for the medicine.
AstraZeneca said on Thursday that recent analyses into why a small number of sub-groups, including North Americans, did not benefit from the drug in a clinical trial suggested “a possible association” with aspirin dose.
Researchers observed reduced efficacy with Brilinta as aspirin dosing increased.
Industry analysts said the aspirin link raised fresh uncertainty about the approvability of Brilinta and could prompt questions about the cost-effectiveness of the treatment.
“Clearly, Brilinta does have benefits over aspirin plus Plavix, but there are question-marks in the U.S. as to what sort of traction they will get,” said Simon Mather of WestLB.
Cardiologists were puzzled — and industry analysts concerned — when the experimental medicine failed to prove better than Plavix in North American patients in the so-called PLATO study, results of which were announced in Barcelona in August.
AstraZeneca filed this month for a licence for Brilinta in Europe and plans to file in the U.S. by the end of the year.
Brilinta proved better than Sanofi-Aventis (SASY.PA) and Bristol-Myers Squibb’s (BMY.N) Plavix overall in the 18,000-patient study, but its failure to prove itself in North American patients was a major talking point.
Clyde Yancy of Baylor University Medical Center in Dallas, who is also president of the American Heart Association, said at the time that the lack of effect in U.S. patients could be a function of treatment patterns there. [ID:nLV50232] (Reporting by Ben Hirschler, editing by Kate Kelland)