The results of a phase 3 trial
assessing the efficacy and safety of surotomycin (CB-183,315
), a novel bactericidal cyclic lipopeptide, versus oral vancomycin in the treatment of Clostridium difficile
infection (C. difficile
) have shown that surotomycin failed to show benefit over vancomycin.
The randomized, double-blind, active-controlled, international multicenter trial, enrolled 608 subjects with C. difficile
infection—confirmed by a positive toxin result. Of those initially enrolled, 285 participants were randomized to receive, 250 mg oral surotomycin twice daily, alternating with placebo twice daily, while 292 patients received vancomycin, 125 mg 4 times daily, orally for 10 days.
“Surotomycin has a narrow spectrum of activity, demonstrating low resistance rates and rapid activity against C. difficile
with similar dose- and time-dependent pharmacodynamics to vancomycin in resolving C. difficile
infection in a hamster model,” Sahil Khanna MBBS, division of gastroenterology and hepatology, Mayo Clinic, said.
Surotomycin however, did not demonstrate superiority for key secondary endpoints including sustained clinical response and clinical response over time, failing to show benefit over vancomycin. The clinical response over time and sustained clinical response were monitored until the end of the trial through a follow-up period of 30–40 days with a maximum of 100 days.
At the end of the treatment, the clinical response for those taking surotomycin (83.4%) was non-inferior to vancomycin (82.1%) with a difference of 1.4%. Through follow-up days, clinical response was no superior to surotomycin, nor sustained a clinical response, 63.3% versus 59% difference. Both treatments were generally well tolerated.