Concert Pharmaceuticals has revealed plans to initiate a Phase II clinical trial of CTP-692 as an adjunctive treatment for schizophrenia, based on positive data from the Phase I programme.
CTP-692 is a deuterium-modified form of D-serine, the endogenous NMDA receptor co-agonist.
Based on documented D-serine data, Concert Pharmaceuticals believes that the compound could potentially restore NMDA receptor activity in select areas of the brain in schizophrenia patients.
In single and multiple-ascending dose Phase I trials involving healthy volunteers, the therapeutic was well-tolerated across the dose ranges evaluated, including the doses meant for Phase II study.
The company noted the absence of renal impairment signs in blood and urine markers of kidney function. It added that the use of non-deuterated D-serine has been limited because of renal safety concerns.
Concert Pharmaceuticals president and CEO Roger Tung said: “We are pleased that CTP-692 demonstrated favourable clinical properties including an excellent safety profile in its Phase I studies, and we look forward to advancing it into Phase II evaluation later this year.”
Intended to investigate the safety, tolerability and pharmacokinetic profile of CTP-692, the Phase I programme comprised a total of three trials.
A crossover study compared CTP-692 to D-serine, while a single-ascending dose trial further assessed the effect of food on CTP-692’s pharmacokinetics and a multiple-ascending dose trial evaluated oral CTP-692 over seven days.
Doses ranging from 0.5g to 4g were compared to placebo in a total of 72 participants in the single- and multiple-ascending dose trials.
Findings showed favourable safety, tolerability and pharmacokinetic profile without any serious adverse events.
In another study involving 11 healthy volunteers in a crossover design with CTP-692 and D-serine, the therapeutic showed increased plasma exposure compared to D-serine.