Optimer Pharmaceuticals has initiated patient dosing in its Phase IIIb trial of Dificid (fidaxomicin) for the prevention of Clostridium difficile-associated diarrhoea (CDAD) in bone marrow transplant patients.
The multi-centre, double-blind study will assess the safety and efficacy profile of Dificid as prophylaxis in individuals undergoing hematopoietic stem cell transplant (HSCT).
Optimer chief scientific officer and R&D senior vice president Dr Sherwood Gorbach said undergoing HSCT weakens the immune system, and patients are often receiving antibiotics, both of which are significant risk factors for the development of CDAD.
"Consequently, the prevalence of CDAD in these patients is high and we believe that DIFICID has potential to prevent CDAD in this high-risk population. We hope that this trial will provide us data supporting this hypothesis," Gorbach said.
Approximately 340 patients are expected to be enrolled in the study in two arms, one administering 200mg of Dificid daily for thirty days and the other with placebo.
Once 170 evaluable subjects complete the treatment and the 30 day post-treatment follow up, a blinded interim analysis will be conducted to re-estimate the sample size based on accumulated data.
The incidence of CDAD from the first dose of study drug through the 30-day follow-up period after the last day of drug is the study's primary endpoint.
The goal of the trial is to achieve a 60% improvement in the CDAD incidence rate in the Dificid group over the placebo group.
The company expects the initial data from the trial in the first half of 2014.
Optimer president and CEO Pedro Lichtinger said; "Pursuing a prophylaxis indication has the potential to help a new population at risk of CDAD and is an important step in the implementation of our life cycle management plan."