Neuren Pharmaceuticals (ASX:NEU) has announced that the primary endpoints for its planned single Phase 3 pivotal clinical trial of NNZ-2591 in Phelan-McDermid syndrome (PMS) have been confirmed at a Type C Meeting with the US FDA.
PMS is caused by a deletion or other change in the 22q13 region of chromosome 22, which includes the SHANK3 gene, or a mutation of the gene. The SHANK3 gene codes for the shank3 protein, which supports the structure of synapses between nerve cells in the brain. It is estimated that between 1 in 8,000 and 1 in 15,000 people have PMS. There are no medications, drugs, or therapies specifically for PMS, which has an overwhelming unmet medical need. PMS has severe quality-of-life impacts on those living with it. The most common characteristics are moderate to severe developmental and intellectual impairment and developmental delay, delayed or absent speech, symptoms of autism, low muscle tone, motor delays, mild to severe epilepsy, behavioural problems and difficulties with socialisation, activities of daily living and self-care.
Neuren CEO Jon Pilcher said, “We are very pleased with the outcome of another constructive discussion with the FDA and are now excited to be able to move forward as planned with the first-ever Phase 3 trial in children with Phelan-McDermid syndrome.”
The co-primary endpoints in the double-blind placebo-controlled study of treatment for 13 weeks will be the change from baseline in the Receptive Communication sub-domain of the Vineland Adaptive Behavior Scales, Third Edition (VABS-3 Receptive-Raw Score) and the overall score in the Phelan-McDermid Syndrome Assessment of Change (PMSA-C, previously referred to as CGI-I in Neuren’s Phase 2 trial).
Neuren said the endpoints pair the caregiver’s assessment of change in one crucial symptom area with the clinician’s assessment of change across multiple aspects of PMS. The company said it remains on-track to commence the Phase 3 trial mid-year 2025, subject to FDA review of the final version of the trial protocol.