Strong Phase II results with Roche's potential first-in-class treatment for the negative symptoms of schizophrenia

Swiss drug major Roche has reported positive results from a 320 patient Phase II proof-of-concept study with its investigational glycine transporter-1 inhibitor RG1678. The study showed that the compound improved both the negative symptoms and the personal and social functioning of patients with schizophrenia reaching statistical significance on primary and secondary endpoints. The drug is being co-developed with Roche's majority-owned Japanese subsidiary Chugai.

Vontobel analyst Andrew Weiss noted the drug trial was in an early stage but was optimistic about its potential. "The drug could have a potential of $1-$2 billion and could be launched in 2016," he said in a client note, reported by Reuters.

Important step in unmet medical need

There are currently no effective therapies available for the treatment of negative symptoms, a core clinical feature of schizophrenia. These symptoms include apathy, lack of pleasure, lack of emotion and poor social functioning. Clinically disabling in more than 50% of all patients with schizophrenia, negative symptoms represent an important unmet medical need, and are associated with a substantial socio-economic burden.

"We are greatly encouraged by these clinical data with the novel glycine transporter-1 inhibitor RG1678," said Eugene Tierney, head of the central nervous system disease biology area at Roche. "Today's therapeutic options fail to address these symptoms and also have many adverse side-effects. New treatment options harnessing novel modes of action such as RG1678 could offer relief to patients with this devastating disease and ease economic burden to society," he added.

The analysis of this double blind phase II study showed that RG1678 has a robust and clinically-meaningful effect in patients with schizophrenia. Improvements were observed on negative symptoms, overall physician's assessment (clinical global impression) and patient's personal and social performance in a prospectively defined intent to treat population. RG1678 was given as an add-on treatment to patients who were stable on antipsychotic therapy and suffered mainly from negative or disorganized thought symptoms. The compound was well tolerated at all doses tested, according to Roche.