Medicines Co. blood thinner still has hope: doctors

* Researchers say new trials warranted

* Say lower mortality, stent clots justify further study

* Caution that cangrelor failed earlier main study goals

By Ransdell Pierson and Bill Berkrot

ORLANDO, Fla., Nov 15 (Reuters) - An experimental Medicines Co blood thinner that failed two late-stage clinical trials earlier this year still holds great promise and deserves to be tested in new studies, researchers said on Sunday.

The company discontinued two large trials of the intravenous drug, called cangrelor, in May after an independent monitoring board deemed it unlikely to prove to be superior to the widely used pill Plavix.

Cangrelor had been tested against Bristol-Myers Squibb Co's (BMY.N) Plavix among patients undergoing procedures to clear their heart arteries of plaque, to see if it was better within 48 hours at reducing incidence of death, heart attack or a need for new heart procedures.

Cangrelor failed the trials because it was not satisfying that combination of study goals, or endpoints. Even so, it sharply reduced overall mortality and the occurrence of blood clots associated with new stents -- tiny scaffold-like devices used to prop open arteries cleared of plaque, researchers said.

Some 0.7 percent of patients taking Plavix by itself died within 48 hours of treatment, compared with 0.2 percent of those who received cangrelor in combination with Plavix, representing a 67 percent reduction for the cangrelor group.