Concert Pharmaceuticals Initiates Clinical Trial For CTP-518

Concert Pharmaceuticals has initiated a Phase 1b clinical study with CTP-518, 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 $12m 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.

Roger Tung, president and CEO of Concert Pharmaceuticals, said: “Preclinical data suggest that CTP-518 has the potential to be administered without pharmacokinetic boosting. 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.Also 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 randomised, double-blind, placebo-controlled study in which study participants will receive CTP-518 or placebo for 14 days.