Yestoday, Neuralstem (NYSE: CUR) announced “very positive and encouraging” topline results from the Phase II trial of NSI-566 in ALS patients. However, Neuralstem stock plunged by 37%. Senior columnist Adam Feuerstein says Neuralstem’s conclusion is “Duh.” Investors appear to agree with his interpretation on the data.
The trial met its primary safety endpoints, but all investors’ eyes have been attracted by the secondary efficacy endpoints. Patients’ disease progression was measured by the standard ALSFRS score. A small slope of decline or positive slope of ALSFRS score means patients are stabilizing or improving.
Neuralstem deemed 7 of the 15 patients as responders, of course, the remaining 8 were non-responders. The average slope of decline for the responders was -0.007 point per day versus -0.1 point per day for non-responders. Let ‘s do a simple math:
average slope of decline of ALSFRS score for all patients=-(0.007×7+0.1×8)/15 point per day=-1.70 point per month
This is not encouraging. According to Adam Feuerstein, patients treated with NSI-566 performed worse than patients in a natural history study.
I just take a look at BrainStorm Cell Therapeutics’ (NASDAQ: BCLI) Phase IIa results disclosed in January 2015. The average slope of decline of ALSFRS score during the three month without treatment was -1.41 point per month. Although cross-trial comparisons are imperfect, NSI-566 looks like ineffective.
Both Neuralstem and BrainStorm are developing stem-cell therapeutics for the treatment of ALS. Neuralstem’s NSI-566 are neuroregenerative neural stem cells, while BrainStorm’s NurOwn are neuroprotective mesenchymal stem cells that are induced to secrete neurotrophic factors.
What concerns me is that Neuralstem’s stem cells are only injected into the spinal cord, while the degeneration of motor neurons involves the whole body of ALS patients.
Neuralstem expects to initiate a larger trial this summer. The company should find a way to pre-select patients who are most likely to respond to NSI-566 before the surgery for stem cells transplantion, if the so-called responders really existed.