The UK company recently filed an Investigational New Drug (IND) application with the US Food and Drug Administration (FDA). However, the agency has put the proposed clinical trial of ReN001 on hold, pending further information from the stem cell specialist. The specifics of this information were outlined during a conference call between the two parties and the FDA said they would also confirm these comments in writing.
Stroke is the single largest cause of adult disability in the world: over half of the estimated 50m stroke survivors worldwide are left with some form of permanent disability. If approved, ReN001 would be the world's first stem cell treatment for a major neurological disorder.
"We are confident that approval to commence human clinical trials with ReN001 will be granted," said Michael Hunt, CEO of ReNeuron.
"We appreciate the diligence with which the FDA are reviewing our IND application, and for providing the company with the opportunity to engage in dialogue at this early stage in the approval process. We will be continuing our dialogue with the FDA as we work towards providing the additional information required."
ReNeuron believe the FDA's questions are "largely as expected and are readily addressable" and that its current preclinical studies of ReN001 "may answer the main points raised by the FDA during the call."
Collins Stewart analyst Navid Malik is also optimistic that the treatment will be approved for trials.
He said: "Whilst it is not known what information the regulators wish to clarify, a conference call request is in our view a positive, given the fact that the FDA could have sent a written response to ReNeuron requiring further detailed information or studies, and has instead opted for a call."
Although Mr Hunt reiterated this sentiment to DrugResearcher.com, he refused to comment further on the situation at this time.
The optimistic mood was reflected in the stock price, which has bounced back from a low last week of around 36p to be back on track at around 45p. Mr Malik also kept a 'buy' rating on the stock, which he considers is substantially undervalued against its US peer group.
Mr Malik added: "There is a precedent for the FDA putting clinical holds on stem cell applications."
This happened to US-based company Stem Cells, which specialise in developing therapies for conditions affecting the central nervous system, liver and pancreas. Its Phase I clinical trial of HuCNS-SC, a treatment for Batten disease, was put on hold for over seven months in 2005 until the company filed an amendment to its initial IND application with the FDA.
Mr Malik said: "We do not believe that there is any substantial issue relating to the clinical hold and anticipate approval once the specific questions the has have been clarified."
ReNeuron is also conducting preclinical research on its ReN005 stem cell therapy for Huntington's disease.