EMA CHMP adopts positive opinion for Optimer's DIFICLIR to treat C. difficile infection

Optimer Pharmaceuticals, Inc. (NASDAQ: OPTR) today announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive opinion for DIFICLIR™ (fidaxomicin) tablets for the treatment of adults suffering with a Clostridium difficile infection (CDI), also known as C. difficile-associated diarrhea (CDAD).

DIFICLIR, which is known as DIFICID™ in the United States (US), was approved by the US FDA in May 2011 for the treatment of CDAD in adults 18 years of age and older. Astellas is Optimer's exclusive licensee to develop and commercialize DIFICLIR in Europe and certain other countries in the Middle East, Africa and the Commonwealth of Independent States.

The CHMP positive opinion is based on Phase 3 clinical studies that were conducted to compare the safety and efficacy of 400mg/day fidaxomicin with 500mg/day oral vancomycin for 10 days in subjects with CDI. The first Phase 3 study was carried out in 629 subjects in North America (US and Canada). The second Phase 3 study was carried out in 535 subjects in North America and Europe. The results of the studies showed that the proportion of subjects in which clinical cure was achieved at the end of 10 days of treatment were similar for both treatments; thus fidaxomicin met its primary endpoint of non-inferiority to vancomycin. Furthermore in both trials, fidaxomicin had a significantly lower rate of recurrence of CDI compared to vancomycin at 30 days after completion of treatment.

"A positive CHMP opinion is an important milestone for Optimer and is a key step to making fidaxomicin more widely available to patients around the globe for this serious disease," said Pedro Lichtinger, President and CEO of Optimer.