Optimer Pharmaceuticals, Inc., a global biopharmaceutical company focused on developing and commercializing innovative hospital specialty products that have a positive impact on society, has received Health Canada approval for Dificid (fidaxomicin) tablets for the treatment of clostridium difficile infection (CDI), in adults 18 years of age and older. The Dificid is now available to treat patients in Canada.

The approval was based on Health Canada's evaluation of two large, multi-national, phase III clinical trials demonstrating that Dificid was as effective as oral vancomycin in providing an initial clinical response and was superior in providing a sustained clinical response for 28 days post treatment. Dificid is the first new treatment for CDI to be approved in Canada in over 20 years.

“CDIs have been an increasing challenge and burden for the Canadian health care system during the last decade and affect the elderly population in a disproportionate manner,” said Dr Karl Weiss Professor of Medicine Maisonneuve-Rosemont Hospital, Faculty of Medicine, Universite de Montreal. “Reducing CDI recurrence is a major objective knowing that 20 per cent to 30 per cent of affected Canadian patients will experience at least one relapse of the disease, escalating over 60 per cent after multiple recurrences.”

The Health Canada product monograph for Dificid highlights some of the important features of the product, including: Narrow spectrum activity that is bactericidal against C. difficile in vitro; Mainly confined to the gastrointestinal tract; Minimal effect on intestinal flora, with studies having demonstrated that fidaxomicin treatment did not affect Bacteroides concentrations or other major components of the microbiota in the feces of CDI patients; Shown to inhibit C. difficile sporulation in vitro; Suppresses the production of both toxin A and toxin B and inhibits toxin gene expression in vitro.

“Awareness of the burden of CDI on the Canadian health care system is high with many health care providers, patients, and caregivers impacted by this devastating infection,” said Paulash Mohsen, president and country manager for Optimer Canada. “This familiarity with CDI will help us as we make Dificid available to Canadian patients in need.”

CDI is the most frequent cause of health care-associated infectious diarrhea in industrialized countries. It is a significant medical problem in hospitals, long-term care facilities and in the community. CDI is a serious illness resulting from infection of the inner lining of the colon by C. difficile bacteria, which produce toxins that cause inflammation of the colon, severe diarrhoea and, in the most serious cases, death. Clostridium difficile-associated diarrhoea (CDAD) is the most common symptom of CDI. Patients typically develop CDI from the use of broad-spectrum antibiotics that disrupt normal gastrointestinal (gut) flora, possibly allowing C. difficile bacteria to flourish. Older patients in particular are at risk for CDI, potentially because of a weakened immune system or the presence of underlying disease. Approximately two-thirds of CDI patients are 65 years of age or older. Historically, approximately 20 per cent to 30 per cent of CDI patients who initially respond to treatment experience a clinical recurrence.

Dificid is the first antibacterial drug indicated for Clostridium difficile-associated diarrhoea (CDAD) to be approved in more than 25 years in the US. It is indicated in the US for the treatment of CDAD in adults 18 years of age or older. Dificid is administered in 200 mg tablets given orally twice daily.