Bayer says data encouraging, wary on read-across

STOCKHOLM Aug 31 (Reuters) - The latest data on Bayer's (BAYGn.DE) key anti-clotting drug Xarelto is "very encouraging" but the company's head of cardiovascular drug development is wary about reading too much into what it means for other clinical trials.

Medical experts and investment analysts are studying results of a trial released on Tuesday in patients with blood clots to try and gauge how Xarelto will fare in another area of long-term use, preventing strokes in people with irregular heartbeats.

Results of a trial called ROCKET-AF will be presented at the American Heart Association annual meeting in November.

"Yes, it is the same dose. Yes, it is again a chronic use. But you have to keep in mind that the population is distinctively different," Frank Misselwitz told Reuters on the fringes of the European Society of Cardiology.

"We see these data as being very encouraging for Xarelto but in terms of cross-reads for ROCKET we have to be very careful."

He noted the study reporting in Stockholm looking at dissolving potentially deadly clots in the legs involved a relatively young group of patients, with an average age below 60, whereas the average age for the ROCKET trial was 73.

"There is a massive difference in the age groups and we know that co-morbidities increase with age, so it makes it difficult to translate these data into the setting of stroke prevention," Misselwitz said.

Bayer is developing Xarelto with Johnson & Johnson (JNJ.N).

(Reporting by Ben Hirschler; Editing by Erica Billingham)