Few options for stroke victims; research continues

By Deena Beasley

LOS ANGELES (Reuters) - More than a decade after the launch of clot-buster Activase, the Genentech Inc drug remains the only option for stroke victims despite high-profile research aimed at improving the odds of recovery from the No. 3 cause of death in the United States.

Since most stroke patients are unable to quickly recognize their symptoms, just a small percentage end up being treated with Activase, an intravenous drug approved for use only within three hours of the onset of a stroke.

Drug companies have sought to widen that treatment window and develop medicines that would protect the brain from damage caused by a stroke, but the field is littered with failures.

Last August, drugmaker Forest Laboratories pulled out of a partnership to develop clot-buster desmoteplase after a late-stage trial failed to show that the drug, which is derived from vampire bat saliva, worked better than a placebo.

Shares of Paion AG, the German biotechnology company that discovered desmoteplase, fell 64 percent after the trial results were announced. But Paion and partner Lundbeck A/S are pushing on with another trial looking at a treatment window of up to nine hours.

Nuvelo Inc on Monday ended development of its experimental stroke drug alfimiprase after it failed to demonstrate effectiveness in unblocking catheters, sending the company's shares down 46 percent.

The biggest risk of clot-dissolving drugs is hemorrhage and they can't be used in patients with evidence of recent bleeding, head trauma, high blood pressure or other risk factors. Even with those restrictions, about 6 percent of patients treated with Activase suffer brain hemorrhage.

"There is a lot of skepticism about any stroke drug due to the recent failures ... all this has frightened the large pharma companies," said Paul Freiman, chief executive of Neurobiological Technologies Inc, which expects interim results late this year from pivotal trials of its experimental stroke drug Viprinex.