Concert Pharmaceuticals reports positive results from Phase I hot flashes trial

Concert Pharmaceuticals, a biotechnology company, has announced positive Phase I clinical trial results of CTP-347, an investigational non-hormonal treatment for vasomotor symptoms or hot flashes.

CTP-347, a novel deuterium-modified analog of paroxetine discovered at Concert, was well-tolerated at all doses. Paroxetine is a serotonin reuptake inhibitor that has been shown to reduce vasomotor symptoms. However, paroxetine inactivates the important liver enzyme CYP2D6 which can lead to serious side effects when used in combination with many common medications.

In contrast, in this study, CTP-347 substantially retained the activity of this key enzyme, potentially enabling its broader use with other drugs. These clinical results confirm Concert’s preclinical observations. The company expects to present the complete Phase I results in 2009.

The Phase I clinical trial was a randomized, single-blind, placebo-controlled, ascending single- and multiple-dose study in 94 healthy volunteers. The primary objective of the study was to evaluate the safety, tolerability and pharmacokinetics of CTP-347.

In this trial, CTP-347 was well-tolerated at all doses evaluated; there were no clinically significant adverse events reported and the pharmacokinetics were consistent with those observed in preclinical studies, the company said.

As part of the multi-dose phase of the study, the extent to which CTP-347 inhibits the drug-metabolizing enzyme, CYP2D6, was evaluated by co-dosing subjects with dextromethorphan, which is metabolized by CYP2D6. In this portion of the study, women dosed with CTP-347 substantially retained their ability to metabolize dextromethorphan, suggesting that time-dependent inactivation of CYP2D6 was not observed with CTP-347 and indicating that CTP-347 may have a reduced potential for drug-drug interactions, the company added.