ReNeuron stem cell test helps mobility in stroke patients but misses endpoint

British biotech ReNeuron has posted generally encouraging midstage data which showed their stem cell therapy could help certain stroke patients move their arms better after being left disabled by their condition. Despite not hitting its primary endpoint, it is still plotting a pivotal test starting next year.

Its CTX cell therapy candidate was being tested in a small phase 2 trial, known as Pisces II, that worked as a single-arm, open-label study in patients living with disability resulting from ischemic stroke.

The study’s primary endpoint was relatively modest: It needed two patients out of 21 to reach a minimum two-point improvement in what is known as the grasping and lifting test, a part of the Action Research Arm Test (ARAT), at three months after treatment.

In the end, three of the 21 patients achieved this at three, six or 12 months respectively after treatment, and were within a group of four responders who also showed “clinically relevant improvements” on the total ARAT score of arm motor performance.

But it missed its target as some responses came later than the three-month target. The biotech however still said that the result was “nonetheless highly encouraging,” and the market tended to agree, with its shares jumping over 22% on the news today.

This was also because “strongly positive results” were also reported in the other endpoints of the study, with seven patients (33%) showing a “clinically relevant improvement” on the Modified Rankin Scale (a measure of disability and dependence) and eight patients (38%) showing a clinically relevant improvement on the Barthel Index (a measure of performance in activities of daily living).

In all, 15 out of 21 patients had a clinically significant response on at least one efficacy measure, with these improvements kept up throughout the follow-up period.

The company says that it will now seek a chat with the FDA and EMA about starting a randomized, placebo-controlled, pivotal trial in patients who are living with disability poststroke.

Olav Hellebø, CEO of ReNeuron, said: “We are delighted that the Pisces II clinical trial has shown our CTX cell therapy candidate has the potential to become a treatment option for patients living with chronic consequences following stroke. We are particularly excited by the response rate seen on the measures relating to disability and activities of daily living, given that these are the most important for patients and their carers.”

Hellebø noted that these measures are also the ones viewed by regulatory authorities as most relevant for late-stage clinical development.

He added that the co has a “strong balance sheet” to fund its planned pivotal study.

Stem cell therapies, once seen as a great hope in the research field for a variety of diseases, have in recent years been beset with testing setbacks, with progress in getting new therapies to market much slower than originally hoped for.

Back in the summer, Teva returned the full rights to a phase 3 experimental heart drug to Mesoblast as it walked away from development. And in the spring, CA-based BioCardia delayed its plans to raise $50 million for its stem cell research.