Human Clinical Data Encompasses Five Years of Post-Transplant Safety

NEWARK, Calif., Oct. 21, 2013 (GLOBE NEWSWIRE) — StemCells, Inc.(Nasdaq:STEM) announced today the results of a four-year observation study in patients with neuronal ceroid lipofuscinosis (NCL), also referred to as Batten disease, who had been transplanted with the Company’s proprietary HuCNS-SC® cells (purified human neural stem cells) in the initial Phase I study. Key results include long-term evidence of safety, up to five years post transplantation, for the surgical transplantation of the HuCNS-SC cells into multiple sites in the brain and at doses of up to one billion cells. The study results represent the first, and thus far only, multi-year data set following transplantation of neural stem cells into human subjects, and supports the feasibility of the Company’s approach in multiple neurological disorders. The data will be presented today by Nathan Selden, MD, PhD, FACS, FAAP, who was co-principal investigator in the studies, at the Congressof Neurological Surgeons Annual Meeting in San Francisco, California.”The NCL study enrolled patients suffering from a severe progressive neurological disorder and the study’s outcome shows that there were no long-term safety or tolerability issues associated with the cells, the immunosuppression regimen or the surgical procedure over the five years following transplantation,” said Dr. Selden, Campagna Chair of Pediatric Neurosurgery at Doernbecher Children’s Hospital and Oregon Health & Science University (OHSU), and incoming President of theCongress of Neurological Surgeons. “Our assessment of the patients’ cognitive and neurological function revealed stable scores in some tests, but the clinical outcomes were generally consistent with the expected course of impairment associated with this neurodegenerative disease. However, three of the six patients transplanted with HuCNS-SC cells have now survived more than five years post-transplant, and in a progressive neurodegenerative disorder, it is noteworthy that each have stable quality-of-life measures.”Stephen Huhn, MD, FACS, FAAP, Vice President, CNS Clinical Research atStemCells, Inc., added, “This was the first clinical test of our HuCNS-SC cells. We are very pleased to have accrued significant multi-year human safety and tolerability data for neural stem cell transplantation into the brain, unmatched in terms of both cell dose and duration of follow up thus far in the field. We are very grateful to all the investigators at OHSU and the families of the patients who were part of this ground-breaking study.”Six patients were enrolled in the Company’s Phase I clinical study in Batten disease. All six were transplanted with HuCNS-SC cells and followed for twelve months after transplantation. Five patients completed the Phase I study and subsequently enrolled in a four-year, long-term observational study, with three of the five surviving to the end of the four-year study. The long-term clinical data appear to be consistent with the natural history of the disease and conclusions about impacting the disease course cannot be made in an open-label trial. The reported adverse events are consistent with the underlying disease and there have been no safety concerns attributed to the HuCNS-SC cells. Magnetic resonance imaging scans of the brain show progressive atrophy consistent with the patient’s neuropsychological performance. Quality-of-life measures remained stable across all three surviving patients.

The Company previously reported post-mortem evidence of engraftment, migration and long-term survival of the HuCNS-SC cells following transplantation and the planned cessation of immunosuppression. The data were based on examination of the brains from three patients who expired from causes related to the underlying disease.