Stem Cell Therapy Shows Safety, Possible Efficacy in Early Trial

Treatment with ISC-hpNSC, an investigational stem cell therapy for Parkinson’s disease, was safe and well-tolerated over at least two years in an early clinical trial in 12 patients.

Results from the small trial, which treated patients at low, medium and high doses, also indicate that the therapy eased Parkinson’s-related symptoms and improved quality of life.

In the open-label Phase 1 trial (NCT02452723), conducted at the Royal Melbourne Hospital in Australia, adults ages 30 to 70, with moderate to severe Parkinson’s, were given the investigational therapy.

Stem cells are notable for their ability to grow and differentiate into other types of cells. The general aim of ISC-hpNSC — which stands for human parthenogenetic stem cell-derived neural stem cells — is to replace the dopamine-producing neurons (nerve cells) that die in Parkinson’s. According to International Stem Cell Corporation (ISCO), the therapy’s developer, ISC-hpNSC also supports the health of neurons in the brain damaged by this disease.

In the trial, the stem cells were injected directly into the striatum and substantia nigra of patients, which are the regions of the brain especially affected by Parkinson’s. Participants were divided into three cohorts or groups, with each four-person group received increasing doses of the therapy: 30, 50, or 70 million neural stem cells (cohort 1, cohort 2, and cohort 3, respectively).

All patients have now completed at least two years of post-treatment monitoring, the company reported in a press release. Those first treated have been observed for a longer time, at least four years for cohort 1, and at least three for cohort 2.

Results overall indicate the investigational stem cell therapy is safe, according to the trial’s principal investigator, Andrew Evans, MD, director of movement disorders at the Royal Melbourne Hospital.

“The safety evaluation is based on the initial 12 months of safety data from the first cohort (low dose), the second cohort (mid dose), and the third cohort (high dose). In all three cohorts there have been no serious adverse effects related to the transplanted ISC-hpNSC cells,” Evans said in the release.

Patients are also being monitored for early evidence of treatment efficacy, with changes from the study’s start (pre-treatment or baseline measures) over time assessed using scales that include the Unified Parkinson Disease Rating Scale (UPDRS), which examines motor skills, daily life activities, complications like dyslexia, and cognitive skills.

Generally, the highest efficacy responses have been seen in patients given the therapy’s middle dose.

At one year post-treatment, people in this second cohort had, on average, a 47% decrease in “off” time compared with their baseline measures. “Off” time refers to times when a person is being treated with levodopa or a similar medication, but their symptoms are not adequately controlled.

Improvements were also reported in “on” time (when symptoms are adequately controlled by therapy), which rose by 42% in middle-dose patients. At two years post-treatment, “off” time for cohort 2 was on average 55% lower than at baseline, while “on time” was 65% higher.

Quality of life scores for cohort 2 also climbed, rising on average by 43% compared with baseline scores at one year post-treatment, and were 45% higher at two years post-treatment. Life quality was measured with the Parkinson’s Disease Quality of Life Score-39.

“We are excited about our phase 1 clinical trial results,” said Russell Kern, ISCO’s executive vice president and chief scientific officer.

“Patients, followed for over two years after cell transplantation, have reported, on average, improvements in a Parkinson’s disease specific measures, when compared to baseline evaluations,” Kern said. “In this context, the results are very encouraging that the ISC-hpNSC transplanted cells are not only well tolerated, but also may be effective.”

Patients will continue to be evaluated every six months for another five years in the study’s extension phase.