Newron's Merck KGaA-in licensed compound fails Rett Syndrome study, shares wilt
Mutations in a gene called MECP2 were identified as the cause of Rett Syndrome in 1999 inside a laboratory at the Baylor College of Medicine — the same year, Italian drug developer Newron Pharmaceuticals was born. On Monday, the company’s experimental drug, sarizotan, failed a Phase II/III study in patients with the severe neurodevelopmental disorder that has no approved therapies.
In-licensed from Merck KGaA, the compound is designed to modulate the activity of neurotransmitters and was abandoned by the German drugmaker in 2006 after a pair of failed pivotal studies in Parkinson’s disease. Now, Newron is also terminating its developmental program in Rett syndrome.
The trial tested two doses of sarizotan (10 mg and 20 mg) against a placebo in 129 patients with the disease that almost exclusively affects females, and is characterized by a loss of acquired fine and gross motor skills as well as neurological, cognitive and autonomic dysfunction, which leads to loss of ability to conduct daily life activities, walk or communicate.
The main goal of the study — to induce a reduction in episodes of apnea during waking time compared with placebo — was not met, neither were any secondary goals. Detailed data will be presented at a later date, Newron said.

“The results of this well designed and executed study, based on highly promising data from a genetic model of Rett syndrome in mice, indicate the difficulties inherent in translating effects in animal models to human clinical studies,” the company’s CMO Ravi Anand said in a statement.
The company’s shares cratered more than 68% on the Swiss stock exchange to CHF 1.98.
“This high-risk programme was a key focus for the stock, with sarizotan underpinning c.70% of our CHF40/share PT (price target),” Jefferies analysts wrote in a note.
New York biotech Anavex is another company evaluating its lead experimental drug, blarcamesine, in patients with Rett Syndrome — in February, the FDA granted the drug fast track status for the indication. Acadia Pharmaceuticals, the maker of the Parkinson’s disease drug Nuplazid, has an experimental Rett syndrome drug in late-stage development. GW Pharma, the first-ever company to get a natural cannabis-derived therapy approved by the FDA, also has a CBD drug-in-development for Rett, while the cat tranquilizer ketamine is also being evaluated by an academic group for the condition.
Newron, meanwhile, is now left with two eggs in its basket. It gets royalty income from its Parkinson’s disease drug, Xadago, which is sold by its partners in different parts of the world. The other drug in the company’s pipeline, evenamide, is being developed for schizophrenia, although Covid-19 has delayed late-stage enabling trials.