Preliminary Findings of International, Six Hour-Window Stroke Study Available.

INGELHEIM, Germany--(BW HealthWire)--July 10, 1998--Boehringer Ingelheim announced today preliminary findings from the European Cooperative Acute Stroke Study II (ECASS II) which showed an unexpected low overall mortality compared to previous stroke clinical trials. The study, however, failed to show statistically significant clinical benefit in stroke patients treated with Alteplase (rt-PA) compared to placebo.

ECASS II is a placebo controlled randomized trial of acute ischemic stroke patients presenting within 0-6 hours of symptom onset. The study evaluated a dose of 0.9 mg/kg rt-PA with a maximum total dose of 90 mg. Sponsored by Boehringer Ingelheim, the study was conducted by a steering committee consisting of an international group of experts and was monitored by an independent external data safety and ethics committee. The study was conducted in 108 centers throughout Europe, Australia and New Zealand and it included 800 randomized patients in the primary analysis.

The primary endpoint of the study -- defined by the proportion of patients that had no or minimal functional deficit at Day 90 as assessed by the Modified Rankin Scale scores zero and one versus two to six (six equivalent to death) -- did not reach statistical significance. There was an unexpectedly high placebo response rendering the efficacy evaluation inconclusive. However, the observed effects were indicative of a small but consistent efficacy signal across endpoints.

The main safety objective from the study was to reach a mortality rate not greater than that observed in ECASS I. This was clearly achieved with an overall mortality reduction of about one half of that observed in ECASS I. There was also no difference in mortality between rt-PA and placebo in ECASS II. Taking into account all intracranial hemorrhages (ICHs), there was no apparent difference between the treatment groups. However, as observed in previous trials, such as the U.S. NINDS study and ECASS I (both published in 1995), an increased frequency of more severe ICHs was reported in the rt-PA group.

The NINDS study demonstrated a significant clinical benefit of rt-PA for stroke patients treated within three hours of symptom onset as compared to placebo. The most common serious side effect from therapy was symptomatic ICH, which occurred in 6.4 percent of treated patients versus 0.6 percent of patients in the placebo group.

A detailed analysis of the findings will be presented at the Third Congress of the European Federation of Neurological Societies (EFNS) in September in Seville, Spain.

CONTACT: Boehringer Ingelheim GmbH

Judith von Gordon, + 49 6132 773582

or

Pamela S. DeMala, 203/798-4700