Sarizotan is an oral therapy being developed by Newron Pharmaceuticals to treat breathing problems in Rett syndrome patients. It is currently being tested in a Phase 2 clinical trial.

How Sarizotan works

Breathing problems are common in Rett syndrome patients, who can experience shallow breathing, hyperventilation (breathing too fast), breath-holding (taking a breath and failing to let it out), swallowing air, or apnea (failing to take breaths after exhalation). These episodes are involuntary and may cause dizziness, reduce mental focus and coordination, and interfere with basic tasks such as eating and drinking.

Studies in Rett syndrome patients have shown deficits in the amount of serotonin and other critical chemical messengers in the brain that transmit neuronal messages.

Sarizotan is a chemical compound that binds to serotonin (5-HT1A) and dopamine (D2-like) receptors in brain cells. It has been shown to make up for the deficits in serotonin levels in the brain and restore normal breathing in mouse models.

Sarizotan in clinical trials

In preclinical studies using three different mouse models of Rett syndrome, sarizotan reduced apnea by nearly 75–80% and corrected irregular breathing patterns.

Newron Pharmaceuticals is currently running a Phase 2 randomized, double-blind, placebo-controlled clinical trial (NCT02790034) called the STARS study at multiple centers in the U.S., the U.K., Italy, India, and Australia to evaluate the efficacy, safety, and tolerability of sarizotan in patients with Rett syndrome who experience respiratory symptoms.

Other details

Sarizotan received orphan drug designation for the treatment of Rett syndrome in the U.S. and the E.U. in 2015.


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