BrainStorm Cell Therapeutics Inc. (BCLI) has developed a cell-based product they call “NurOwn.” NurOwn consists of mesenchymal stem cells that have been cultured to secrete a variety of neurotrophic factors (NTFs). These NTFs are a collection of different growth factors that promote the survival of neurons. NurOwn cells were originally developed in the laboratories of Professor Dani Offen and the late Professor Eldad Melamed, at Tel Aviv University. NurOwn cells have been studied extensively and they clearly have the capacity to migrate to damaged areas in the central nervous system (Sadan O, et al., Stem Cells. 2008 Oct;26(10):2542-51), decrease dopamine depletion in a Parkinson’s disease model system (Barhum Y, et al., J Mol Neurosci. 2010 May;41(1):129-37), can promote the survival of photoreceptors in the retina of animals who optic nerves were damaged (Levkovitch-Verbin H, et al., Invest Ophthalmol Vis Sci. 2010 Dec;51(12):6394-400), decrease quinolinic acid toxicity in an animal model of Huntington’s disease (Sadan O, et al., Exp Neurol. 2012 Apr;234(2):417-27), and improve motor function and survival in a genetic model of Huntington’s disease.
On the strength of these experiments, NurOwn cells have also been tested in clinical trials. Because NTF-secreting MSCs (or, MSC-NTF cells) are designed specifically to treat neurodegenerative diseases, most of the clinical trials, to date, have examined of safety and efficacy of MSC-NTFs in patients with neurological disorders. The safety of NurOwn cells was established in a small phase I/II trial with amyotrophic lateral sclerosis (ALS) patients. This was a small study (12 patients), but showed that, at least in this patients population, intrathecal (injected into the central nervous system) and intramuscular administration of MSC-NTF cells in ALS patients with is safe and patients even showed some indications of clinical benefits, but the study was too small to be definitive about the efficacy of these cells.
Now a recently completed randomized, double-blind, placebo-controlled phase 2 study of NurOwn in ALS patients has found that NurOwn is safe and well tolerated and may also confer clinical benefits upon ALS patients.
According to BrainStorm, this phase 2 study achieved its primary objective (safety and tolerability). No deaths were reported in the study and no patients discontinued participation because of an adverse event. All patients in both active treatment and placebo groups experienced at least one treatment-emergent adverse event that tended to be mild-to-moderate in intensity in both groups. Treatment-related adverse events, as determined by a blinded investigator, occurred slightly more frequently in active-treated patients than in placebo-treated patients (97.2 percent vs. 75.0 percent). The largest differences in frequencies were for the localized reactions of injection site pain and back pain, and fever, headache, and joint pain.
However, NurOwn also achieved multiple secondary efficacy endpoints in this trial. NurOwn showed clear evidence of a clinically significant benefit. Most significantly, the response rates were higher for NurOwn-treated subjects compared to placebo at all time points in the 24 weeks during which when the study was conducted.
This clinical trial conducted at three sites in the U.S: Massachusetts General Hospital, UMass Medical School and the Mayo Clinic. 48 patients were randomized to receive NurOwn cells administered via combined intramuscular and intrathecal injection (n= 36), or placebo (n=12). They were followed monthly for approximately three months before treatment and six months following treatment, and were assessed at 2, 4, 8, 12, 16 and 24 weeks.
The primary investigator in this trial, Robert H. Brown of the University of Massachusetts Medical Center and Medical School said, “These exciting findings clearly indicate that it is appropriate to conduct a longer study with repetitive dosing.”
Subjects treated with NurOwn in this trial showed slowing of progression of ALS and no safety concerns. NurOwn-treated patients also displayed increased levels of growth factors in the cerebrospinal fluid and decreased signs of inflammation after two weeks. These are good indicators that the MSC-NTF cells are orchestrating some kind of beneficial biological effect.
Based on these results, new trials are warranted that will examine repeat dosing at 8 to 12 weeks and employ a larger number of subjects.