Patient recruitment stymies StemCells rare disease program

Unable to recruit enough patients, StemCells Inc. says it's discontinuing a Phase Ib clinical trial in neuronal ceroid lipofuscinosis, also known as Batten disease. The rare neurodegenerative disorder, which hits children under 10, eventually leads to mental impairment, severe seizures, blindness and dementia. It is always fatal.

The developer successfully completed a Phase Ia trial of HuCNS-SC human neural stem cells in six patients in 2009. A Phase Ib trial was set up to evaluate the cells in an additional six patients in earlier stages of the disease, but over a six-month period investigators were unable to enroll even a single patient. StemCells VP Stephen Huhn said the company's struggle to recruit patients highlights just how difficult it can be to conduct a rare disease trial. "Out of 22 initial prospects, not one patient has met the entry criteria," he explained, noting that larger trials would be almost impossible to conduct in a reasonable amount of time.

CEO Martin McGlynn said that while the trial cancellation was a disappointment, StemCells was able to take some lessons from the study. "...[W]e have established that we can safety transplant meaningful doses of HuCNS-SC cells directly into the brain, and that patients can tolerate both the surgical intervention and the immunosuppression regimen. We also now have evidence that, once transplanted, the cells are capable of engrafting and surviving long-term, suggesting the possibility of durable clinical benefit." He added that no long-term negative side effects were observed in patients who received the cells.

- here's StemCells' release