Concert reports encouraging results for oxazolidinone antibiotic

In the preclinical study, C-20081 had a 43% increase in plasma half-life compared to linezolid, which might allow for lower overall drug exposure and improved tolerability with a once-daily dose.

Concert has evaluated the effect of selective deuterium modification on linezolid’s metabolic and pharmacokinetic properties in primates. C-20081 demonstrated an intravenous (IV) half life of 6.3 hours, compared to 4.5 hours for linezolid. The human single-dose IV half-life of linezolid is reported to be 4.4 to 4.9 hours.

Compared to linezolid, C-20081 had equal in vitro potency across hundreds of bacterial strains, the company said. Concert believes that the combination of potent antibacterial activity and long plasma half-life could result in a superior dosing profile.

C-20081 is a novel compound in the same chemical class as linezolid developed from Concert’s deuterium chemistry platform. Linezolid is an FDA-approved antibiotic for the treatment of serious bacterial infections including methicillin-resistant Staphylococcus aureus (MRSA).

Roger Tung, president and CEO of Concert Pharmaceuticals, said: “Based on our preclinical results, we believe that C-20081 warrants further investigation as a potential once-daily antibiotic for serious bacterial infections. These include MRSA, a virulent hospital and, increasingly, community-acquired infection with high rates of morbidity and mortality, as well as drug-resistant tuberculosis. With its pharmacokinetic profile, we believe C-20081 holds promise for improving patient compliance and thereby enhancing efficacy in both outpatient and long-term care settings.”