Phase III trial of delafloxacin for ABSSSI meets primary endpoint-Melinta Therapeutics

Melinta Therapeutics reported positive top-line results from the first of two Phase III PROCEED studies (study RX-3341-302, NCT01811732) to evaluate captisol-enabled delafloxacin compared with vancomycin + aztreonam for the treatment of patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSI). Delafloxacin met the study�s primary objective endpoint of a reduction in the measurement of lesion erythema at the primary infection site at 48- to- 72 hours, the endpoint required by the FDA. Delafloxacin also was comparable to vancomycin in the study�s secondary endpoints, including investigator assessment of signs and symptoms of infection at the follow-up visit, a metric required by the EMA.

Melinta reports that delafloxacin was shown to be well tolerated among study participants. Mild gastrointestinal symptoms were the most common treatment-related adverse events reported for delafloxacin, and rarely led to study discontinuation. Melinta expects to make complete results from this study available as a presentation at an upcoming medical meeting and a publication in a peer-reviewed medical journal.

Comment:The drug is more active (lower MIC90) than other quinolones against Gram-positive bacteria such as MRSA. In contrast to most approved fluoroquinolones, which are zwitterionic, delafloxacin has an anionic character, which results in a 10-fold increase in delafloxacin accumulation in both bacteria and cells at acidic pH. This property is believed to confer to delafloxacin an advantage for the eradication of Staphylococcus aureus in acidic environments, including intracellular infections.