Allogeneic cell therapy does not improve short-term outcomes in acute ischemic stroke

Key takeaways:

• The study examined 206 older adults with acute ischemic stroke.
• The proportion of “excellent” outcomes at day 90 did not differ significantly between treatment groups.

For older adults with acute ischemic stroke, IV administration of an allogeneic cell therapy within 18 to 36 hours of onset was found to be safe but did not improve short-term outcomes, researchers reported in JAMA Neurology. 

"Evidence-based reperfusion therapies, including intravenous thrombolysis and mechanical thrombectomy, are widely used for stroke treatment,” Kiyohiro Houkin, MD, of Hokkaido University in Japan, and colleagues wrote. “This dynamic landscape highlights the need for new treatment options and expansion of the therapeutic window.”

Houkin and fellow researchers sought to examine the safety and efficacy of MultiStem, a bone marrow–derived, allogeneic, multipotent adult progenitor cell therapy, when administered within 18 to 36 hours of ischemic stroke onset.

Their analysis drew data from The Treatment Evaluation of Acute Stroke Using Regenerative Cells (TREASURE) multicenter, double-blind, parallel-group, placebo-controlled phase 2/3 randomized clinical trial, conducted at 44 academic and clinical centers in Japan between November 2017 and March 2022.

A total of 206 adults (mean age 76.5 years; 54.4% male) with detected presence of acute ischemic stroke measured by a score of eight to 20 in the National Institutes of Health Stroke Scale (NIHSS) at baseline, confirmed acute infarction involving the cerebral cortex and measuring more than 2 cm on the major axis (determined with diffusion-weighted MRI), and a modified Rankin Scale (mRS) score of 0 or 1 prior to stroke onset, were included.

Participants were randomized 1:1 to receive either IV MultiStem in one single unit of 1.2 billion cells (n = 104) or intravenous placebo (n = 102), with randomization organized according to baseline NIHSS score, receipt of reperfusion and age.

The primary endpoint safety and “excellent outcome” at day 90 measured as a composite of mRS score of one or less, a NIHSS score of one or less, and a Barthel index score of 95 or greater. Secondary endpoints included excellent outcome at day 365, mRS score distribution at days 90 and 365 and mRS score of zero to one and zero to two at day 90.

According to results, researchers found no between-group differences with respect to both primary and secondary endpoints.

The proportion of excellent outcomes at day 90 did not differ significantly between the treatment groups (12 [11.5%] vs. 10 [9.8%], adjusted risk difference, 0.5% [95% CI, 7.3% to 8.3%]), while the frequency of adverse events was also similar between treatment groups.

“Intravenous allogenic cell therapy within 18 to 36 hours of ischemic stroke onset failed to demonstrate a short-term therapeutic effect,” Houkin and colleagues wrote.