Enrollment Complete for STARS Study of Sarizotan for Apnea in Rett Syndrome Patients

Patient enrollment is now complete for the pivotal STARS study investigating the safety, tolerability, and effectiveness of sarizotan in Rett syndrome patients with respiratory abnormalities, Newron Pharmaceuticals announced.

Top line results from the Phase 2/3 clinical trial are expected in the last quarter of 2019.

Sarizotan was developed originally by Merck KGaA as a therapy for levodopa-induced dyskinesia (abnormal, involuntary muscle movements) commonly seen in Parkinson’s disease.

Levodopa, a medication that helps counteract the shortage of dopamine in the brain, is the gold standard for treatment of Parkinson’s motor symptoms. However, more than half the patients who use levodopa experience dyskinesia within the first five years of treatment.

Although sarizotan’s clinical studies were discontinued for Parkinson’s disease, it now may become the first medicine approved to benefit a key symptom of Rett syndrome. In preclinical studies, sarizotan markedly improved lung function in a mouse model of Rett syndrome.

The Sarizotan Treatment of Apneas in Rett Syndrome (STARS) study (NCT02790034) has recruited more than 130 Rett syndrome patients (minimum age four years) with clinically significant impaired respiratory function (defined as at least 10 episodes of apnea, for more than 10 seconds each, per hour while awake). The study will be conducted at 14 centers throughout the U.S., Europe, Asia, and Australia.

Apnea (temporarily stopping breathing) is a major feature of Rett syndrome and is present in about 70% of patients, contributing to other co-morbidities, as well as to a reduced quality of life.

Participants will be randomized to receive daily oral doses of either sarizotan (10 to 20 mg, based on age and weight), or a placebo, for 24 weeks.

The trial’s primary outcome is to assess the therapy’s potential to reduce apnea when compared to placebo. The recordings of patients’ respiration will take place at their homes at four different time points during the 24 weeks using a state-of-the art medical device.

To date, treatment with sarizotan has been well-tolerated, with only minor cases of treatment discontinuation due to adverse side effects or lack of effectiveness.

Approximately 90% of the patients who completed the 24-week period have now joined a long-term open-label extension study in which all patients will receive sarizotan, including those first randomized to the placebo group.

An independent international safety monitoring board, responsible for surpervising the safety of the patients, has recommended the study continue without changes.

Early data, reported in October 2018, from more than 100 patients showed that 70% underwent clinical significant improvements from their apnea condition.

If positive, the results from the STARS study may support Newron’s submission of a marketing authorization of sarizotan for Rett syndrome in the U.S., Canada and Europe.