UK-based stem cell company ReNeuron says that the US Food and Drug Administration has placed on hold the company’s recently-filed Investigational New Drug application to commence a Phase I clinical study for its ReN001 stem cell therapy for stroke.

The firm said that the FDA “orally confirmed” that it has placed the proposed study, which followed the world's first such filing concerning a neural stem cell treatment for a major neurological disorder, on hold but no reason has been given for the move. ReNeuron added that a telephone conference call with the agency to discuss the application is expected to take place later this week, after which it will make a further announcement.

The news would, on the surface, appear to be a major blow to ReNeuron, but chief executive Michael Hunt was not fazed by the agency’s decision. Indeed, he claimed that “we are encouraged to be able to engage in an immediate dialogue with the FDA regarding our IND application, now that the initial review process has taken place.”

He added that “given the ground-breaking nature of our ReN001 therapy and the lack of comparable approaches addressing stroke, it is not surprising that the FDA might wish to raise questions or make comments at this point in the approval process.”

Analyst unworried by halt

Mr Hunt’s enthusiasm was shared by analyst Navid Malik at Collins Stewart who said that “whilst it is not known what information the regulators wish to clarify, a conference call request is, in our view, a positive,” especially compared to a written response from the FDA demanding further detailed information.

Mr Malik also noted that that there is a precedent for the agency “putting clinical holds on stem cell applications,” noting that Stem Cells Inc of the USA had its Battens disease IND put on hold. The issues raised were eventually cleared up and a clinical trial recently began. The analyst went on to say that “we do not believe that there is any substantial issue relating to the clinical hold and anticipate approval once the specific questions the FDA has have been clarified.” Collins Stewart has a ‘buy’ recommendation on the stock.

As well as for stroke, ReNeuron is developing stem cell therapies for Huntington's disease, Parkinson's disease, type 1 diabetes and diseases of the retina.