Bitopertin

Bitopertin structure

Bitopertin (also known as GLYT-1, RO-4917838, or RG1678) is an investigational drug that is currently being explored for its potential to enhance the efficacy of antipsychotics in treating specific symptoms of schizophrenia. If approved for use, bitopertin would stand out as a pioneering member of a novel class of treatments for patients with schizophrenia.

Mechanism of Action

Bitopertin functions as a glycine transporter type 1 (GlyT1) inhibitor. This mechanism works to increase concentrations of the neurotransmitter glycine, by inhibiting its reuptake from the synaptic cleft. Glycine operates as a co-agonist, together with glutamate, at N-methyl-D-aspartate (NMDA) receptors. There is evidence to suggest that malfunctions of NMDA receptors could be intricately tied to the onset of schizophrenia. By modulating glutamatergic signalling and raising glycine levels in the synaptic cleft, NMDA receptor function may be potentiated, potentially alleviating symptoms of schizophrenia.

Dosage

Bitopertin is intended to be taken orally. The recommended doses under investigation are 10 mg or 20 mg, to be taken once daily, with a treatment duration of 56 weeks.

Development and Collaboration

Roche, a global healthcare company, is currently working in collaboration with Chugai to co-develop RG1678 on an international scale.

Clinical Studies

In a notable Phase II proof-of-concept study, patients who were administered RG1678 witnessed a marked improvement in their Negative Symptom Factor Score within a span of 8 weeks. More specifically, scores shifted from −4.86 in the placebo group to −6.65 in the treatment group (with a significance of p<0.05, based on the per-protocol population). Moreover, a significant 83% of RG1678-treated patients reported an enhancement of negative symptoms on the CGI-I1, as opposed to the 66% observed in the placebo group (with a significance of p<0.05, according to the per-protocol population).

Potential Impact

Should bitopertin gain licensing approval, it would pave the way for a novel treatment approach that could significantly benefit patients experiencing persistent negative symptoms or sub-optimally managed positive symptoms associated with schizophrenia.