Athersys announces that its partner, Healios K.K., reported topline data from the TREASURE multistem ischemic stroke study.

The randomized, double-blind placebo-controlled study included patients with moderate to moderate-severe ischemic stroke (baseline NIHSS 8-20) with administration of a single dose of MultiStem cells (invimestrocel) or placebo by intravenous infusion within 18-36 hours of the event. The trial enrolled 206 patients and was conducted by 48 sites in Japan.

Topline Results: i. Improvement in pre-specified measures of functional “independence” and good outcomes, such as mRS less than 2, Barthel Index greater than 95 and Global Recovery, associated with MultiStem treatment. ii. The primary endpoint, Excellent Outcome at 90 days, did not reach statistical significance in this population. iii. Overall, consistent improvement in essentially all measured functional outcomes over time through one year, supporting long-term impact on and continued improvement in the quality of life of treated patients. iv. High potential for success on Athersys’ MASTERS-2 primary outcome measure, mRS shift, suggested by the results for the TREASURE patients who were representative of the current enrollment for MASTERS-2. v. No material differences in safety outcomes, including mortality and life-threatening adverse events between the treatment and placebo groups.

"We are enthusiastic about the topline results from the TREASURE ischemic stroke trial in Japan,” remarked Dan Camardo, Chief Executive Officer of Athersys, Inc. “The preliminary data analyses suggest a path forward for our partner, Healios, in Japan, and gives us further confidence in our MASTERS-2 Phase III ischemic stroke study being conducted in the United States, Europe and the Asia-Pacific region. We look forward to continued collaboration with Healios in working to bring this important therapy to the market in Japan.”

Distinctive Characteristics of TREASURE Patient Population and Favorable Read-through to MASTERS-2 Study: The TREASURE patient population was substantially older than the MASTERS-1 population (and older than expected in the design of the TREASURE study) with moderately greater stroke severity. The median age for TREASURE patients was 78 years, compared to 63 years in the MASTERS-1 study. The MASTERS-2 population is expected to be significantly younger, with lower average stroke severity, than the TREASURE population, based on current enrollment information. Compared to the MASTERS-1 population, slower and less robust recovery would be expected within the TREASURE patient group, making measures of independence and good outcomes, such as mRS less than 2 and Barthe Index greater than 95, more clinically relevant than “excellent outcomes” or “ideal” health status post-stroke. The modified Rankin Score (mRS) measures global disability on a 7-point scale and the Barthel Index evaluates a patient’s ability to perform specific activities of daily living on a 100-point scale, and both are commonly used to assess clinical outcomes over time following stroke.

The TREASURE study adds considerable new information about the MultiStem treatment effect in older patients, aged 80 years and older, not previously studied in MASTERS-1 and who are expected to represent a limited proportion of subjects in the ongoing MASTERS-2 study. At the same time, it provides important information for confirming and refining expectations for the MASTERS-2 study.

New top-line data from Healios K.K.’s placebo-controlled Phase II/III TREASURE study with the stem cell therapy MultiStem in ischemic stroke showed evidence of therapeutic impact on multiple clinically relevant endpoints over one year. But while Healios said the preliminary results for its lead asset suggested long-term impact on, and continued improvement in, the quality of life of treated patients, the trial missed its primary endpoint.