The European Commission has granted a marketing authorization for DIFICLIR™ (fidaxomicin) tablets to treat adults with Clostridium difficile infections (CDI), also known as C. difficile-associated diarrhea (CDAD), in the European Union. The announcement was made by Astellas Pharma Europe Ltd., a European subsidiary of Tokyo-based Astellas Pharma Inc. and Optimer Pharmaceuticals, Inc.

Ken Jones, President and CEO of Astellas Pharma Europe Ltd commented:

“Treatment for CDI has changed little in the past 20 years, even though the disease has a major impact on patients’ health and quality of life and is potentially fatal. The EU approval of DIFICLIR, a novel macrocyclic antibiotic that specifically targets C. difficile bacteria, is therefore an important advance for patients suffering from CDI.”

CDI, one of the most common causes of diarrhea linked to antibiotics, can lead to bowel surgery and even death in severe cases. In hospitals, nursing homes and other long-term care facilities, CDI represents a substantial problem, with recurrence rates of up to 25% in patients within 30 days of initial treatment with current therapies.

DIFICLIR’s EU approval was granted based on two Phase III clinical studies, which compared the efficacy and safety of 400mg/day oral DIFICLIR with the only approved treatment of CDI, 500mg/day oral vancomycin, for a 10-day duration of treatment in adults with CDI in Europe and North America.

DIFICLIRs primary endpoint was determined as non-inferiority to vancomycin, which was met by achieving clinical cure in similar proportions of participants in a comparison of both drugs. In both trials, researchers determined clinical cure as patients who no longer needed further CDI therapy two days after completion of study medication.

The researchers also observed potential advantages of DIFICLIR over vancomycin; DIFICLIR reduced the rate of CDI recurrence substantially in comparison with vancomycin. Patients who received DIFICLIR had a substantially higher chance of their diarrhea to resolve without recurrence within 30 days of completing the therapy compared with those patients who received vancomycin. The researchers also reported that the disruption of the normal intestinal flora was minimal in patients treated with DIFICLIR and that the drug caused only few systemic adverse events compared with vancomycin.

Professor Mark Wilcox, Professor of Medical Microbiology at the Leeds Teaching Hospitals & University of Leeds commented:

“The high rate of disease recurrence is the greatest limitation of current treatments for CDI. The significant reduction in disease recurrence by DIFICLIR compared with vancomycin is a key step to reducing the morbidity associated with CDI, and this new treatment option is a welcome addition that has the potential to improve the patient experience”.

DIFICLIR, known as DIFICID™ in the U.S. was discovered and developed by Optimer and gained the US FDA approval (US Food and Drug Administration in May 2011 to treat CDAD in adults aged 18 years and above. Optimer’s exclusive licensee for DIFICLIRs development and commercialization in Europe, the Middle East, Africa and the Commonwealth of Independent States is a company called Astellas Pharma Europe Ltd.

CDI is caused by an infection of the internal lining of the colon through C. difficile bacteria and is a serious disease. The bacteria produce toxins, which cause inflammation of the colon as well as diarrhea. In severe cases, CDI can lead to death. Patients commonly develop CDI after using broad-spectrum antibiotics. These disrupt the normal gastrointestinal flora and enable C. difficile bacteria to flourish. Patients aged 65 years or older are at a particularly high risk of developing or recurring CDI.

CDI incidents are a substantial financial burden to healthcare systems, particularly in cases where extended hospitalization is required.

Written by Petra Rattue