FDA grants ‘breakthrough’ status to antibiotic alternative as ContraFect rushes to join fight against superbug
An experimental drug that promises to be the first anti-infective agent to prove superior to vancomycin — an antibiotic approved in 1958 — has notched the FDA’s “breakthrough” status.
ContraFect said the designation was based on Phase II data in which exebacase was tested against a superbug known as methicillin-resistant Staph aureus, or MRSA. In a subgroup analysis, the clinical responder rate at day 14 was 42.8% higher than that among those treated with standard of care, the company said (p=0.010).
The 21% reduction in 30-day all-cause mortality, however, was not statistically significant with p=0.056.
Demonstrating superiority marks a first for the MRSA field, emphasized Roger Pomerantz, who jumped from Seres to become CEO for ContraFect last April. Allergan’s Dalvance, a structural relative to vancomycin, was approved based on non-inferiority.
ContraFect is now conducting a pivotal Phase III study to examine exebacase’s efficacy in all infections caused by Staph aureus, including right-sided endocarditis.
“Based on our interactions with the FDA regarding streamlined development of exebacase, this single Phase 3 study, in addition to the full package of data generated to date, may serve as the basis of a Biologics License Application for FDA review and potential approval of exebacase,” CMO Cara Cassino said in a statement.
MRSA, which comprises a group of Gram-positive bacteria, can cause infections in the skin, the heart, the respiratory system, bone and joint, and even the central nervous system.
Taking a page from bacteriophages — viruses that infect bacteria — ContraFect’s drug is a cell wall hydrolase enzyme, or lysin, that induces bacterial death by puncturing the cell wall. Its inventor, Vincent Fischetti of Rockefeller University, calls it an antibiotic alternative.
The company forecasts a $700 million market for the MRSA bacteremia indication provided that exebacase delivers in Phase III and gets the superiority label, CFO Michael Messinger told Endpoints News. They are also gunning for an expanded label covering all Staph aureus.