Neuren’s NNZ-2566 is a program that NIR has been following for more than a decade. NNZ-2566 is a small molecule analog of Glypromate, which itself is the synthetic version of an IGF-1 subunit. Long focused on TBI (with PhIIb data due next year), reports of impact in MECP2 model mice led to a Phase II trial of NNZ-2566 in Rett Syndrome, with possible mechanisms including the spurring of dendritic growth, reduction of microglial activation, attenuation of apoptotic gene expression, and inhibition of inflammatory cytokine production.
Neuren has just reported the results from that 53 pt PhII trial, which enrolled Rett patients between the ages of 16 and 45, treating them for four weeks. Given the chronicity of the condition, and the brevity of treatment, the odds against a clear signal were quite high. But compared both with the placebo group and based on intra-subject changes, three outcome measures showed benefit, based on both physician and caregiver ratings, the other three showed the equally vital outcome of no deleterious effects. The p value was .023.
Admittedly, this was a small and short-duration study, but given that there is nothing at present that addresses the core pathophysiology of Rett Syndrome, a devastating neurodevelopmental disorder that often leaves its (exclusively female) patients unable to speak or walk (20,000 or more Rett patients in the US), this evidence of a signal is encouraging. It constitutes something more than a Hint of Concept, but not quite Proof, the latter will require a larger study and one that tests the drug in a younger population. But in a younger population, there may also be an opportunity for a more robust impact as well, given that the progressive loss of function might be arrested at an earlier stage. This is a welcome instance of a Company that persevered for many years in obscurity, for whom the investment of time and resources may have finally paid off.