Concert Pharmaceuticals commences Phase 1b clinical study of its CTP-518 HIV protease inhibitor

Concert Pharmaceuticals, Inc. announced today that it has initiated a Phase 1b clinical study with CTP-518, its investigational oral HIV protease inhibitor for the treatment of HIV infection. In connection with the start of this multiple ascending dose arm of the Phase 1 study, Concert will receive a $12 million milestone payment under the company’s strategic alliance with GlaxoSmithKline. The Phase 1b study will be used to assess the ability of CTP-518 to maintain acceptable therapeutic blood concentrations without a boosting agent such as ritonavir. It will also be used to determine doses for subsequent studies in HIV-infected patients.

“Preclinical data suggest that CTP-518 has the potential to be administered without pharmacokinetic boosting,” said Roger Tung, Ph.D., President and CEO of Concert Pharmaceuticals. “Ritonavir co-administration is currently recommended for all marketed HIV protease inhibitors. Our goal is to provide patients with a potent and well-tolerated once-daily therapy without the side effects, inconvenience and expense of an additional drug.”

The initial Phase 1 clinical trial is designed to evaluate the safety, tolerability and pharmacokinetics of CTP-518 in healthy volunteers after single and multiple doses. In addition, the Phase 1 study is intended to establish the pharmacokinetic enhancing effect of deuterium incorporation in CTP-518, and to determine whether CTP-518 dosed once-daily can maintain blood levels expected to be sufficient to suppress HIV replication when used as part of a standard three drug combination regimen. The current standard of care is to co-administer all HIV protease inhibitors with ritonavir, except in patients who cannot tolerate ritonavir. The multiple ascending dose phase is a randomized, double-blind, placebo-controlled study in which study participants will receive CTP-518 or placebo for 14 days.

In June 2009, Concert and GlaxoSmithKline announced a potential $1 billion strategic alliance to develop three deuterium-containing medicines, including CTP-518. Concert has responsibility for research and development activities of CTP-518 through completion of Phase I studies. After the completion of the Phase I program, GSK may elect to obtain an exclusive, worldwide license to CTP-518. At such time, GSK would assume responsibility for development and commercialization.

Concert Pharmaceuticals, Inc.