The Italian biopharmaceutical firm has also filed an application for orphan designation in the US.
RTT primarily affects females with an estimated prevalence ranging from 1:10-20,000 females and there are no approved treatments available for this disorder.
The disorder is characterized by a loss of acquired fine and gross motor skills, development of neurological, cognitive and autonomic dysfunction leading to loss of ability to conduct daily life activities, ambulate or communicate.
The company said that sarizotan, a 5HT1A agonist and D2 agonist/antagonist, has been associated with a 70-85% reduction of apneas and hyperventilation episodes in a genetic (MeCP2) knockout model, both after acute and chronic dosing.
Newron CMO Ravi Anand said: "Newron plans to demonstrate the reduction of episodes of apnea and hyperventilation in patients with RTT by Sarizotan.
"This reduction in respiratory symptoms is likely to improve quality of life of patients, caregivers and in long term treatment may reduce secondary complications and increase longevity.
"Newron is currently in advanced discussions with regulatory authorities in Europe, the US and Canada on the proposed clinical development program."
In preclinical studies, sarizotan has been fully seen evaluating its toxicological effects and metabolic profile, without any significant safety findings.