Concert Pharmaceuticals Announces Positive Results from Phase I Clinical Study of CTP-347

First Clinical Demonstration of Concert’s Technology Platform

LEXINGTON, Mass.--(BUSINESS WIRE)-- Concert Pharmaceuticals, Inc. announced today positive Phase I clinical trial results of CTP-347, an investigational non-hormonal treatment for vasomotor symptoms (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 1 results at a future medical meeting in 2009.

“After our encouraging preclinical findings with CTP-347, we were pleased to see a consistent deuterium effect in a clinical setting,” stated Roger Tung, Ph.D., President and Chief Executive Officer of Concert Pharmaceuticals. “In preclinical studies, Concert has shown that selective deuterium substitution can improve the metabolic fate of drugs across a variety of parameters. This study addresses one important parameter and supports our belief that deuterium technology has great potential for rapidly creating best-in-class medicines with reduced risk.”

The Phase 1 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. 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.

About Deuterium

Deuterium is a safe, non-radioactive relative of hydrogen that can be isolated from sea water and has been used extensively in human metabolic and clinical studies. Since deuterium resembles hydrogen, deuterium-containing compounds are expected to preserve the pharmacological activity of their hydrogen analogs. An important difference is that deuterium is heavier than hydrogen and therefore forms a stronger chemical bond. The stronger chemical bond obtained by selective deuterium modification in select instances may substantially improve the drug’s metabolic properties, potentially resulting in better safety, tolerability and efficacy.

About Concert

Concert Pharmaceuticals is a clinical stage biotechnology company focused on the application of deuterium chemistry to create novel small molecule drugs. Concert’s approach leverages known activity and safety of existing drugs to reduce time, risk and expense of drug research and development. The Company’s pipeline is focused on infectious disease, renal disease, cardiovascular disease, and cancer, among others. Founded in 2006, Concert has raised more than $96 million from leading venture capitalists and institutional investors. For more information on Concert Pharmaceuticals, please visit www.concertpharma.com.

CoNCERT and CoNCERT Pharmaceuticals are trademarks of Concert Pharmaceuticals, Inc.

Contacts

Concert Pharmaceuticals, Inc.
Justine E. Koenigsberg, 781-674-5284
Senior Director, Corporate Communications