Top-line results from Optimer Pharmaceuticals' second fidaxomicin Phase 3 trial in CDI patients

Optimer Pharmaceuticals, Inc. (Nasdaq: OPTR) today announced positive top-line results from the second of two pivotal Phase 3 trials evaluating the safety and efficacy of fidaxomicin (OPT-80) in patients with Clostridium difficile Infection (CDI).  This study was conducted in approximately 100 clinical sites throughout North America and Europe.  The Company plans to use data from this study to support submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) in the second half of 2010.

The trial met the primary endpoint of non-inferiority with 91.7% of patients treated with fidaxomicin (per protocol population) achieving clinical cure vs. 90.6% for Vancocin, the only FDA-approved therapy for CDI.  Importantly, fidaxomicin also had significantly lower recurrence rates and higher global cure rates (defined as cure with no recurrence within four weeks of completing therapy) compared to Vancocin.  Only 12.8% of patients treated with fidaxomicin experienced a recurrence vs. 25.3% of patients treated with Vancocin (p = 0.002).  Additionally, 79.6% of patients treated with fidaxomicin achieved a global cure versus 65.5% of patients treated with Vancocin (p < 0.001). As in the first Phase 3 trial, fidaxomicin was well-tolerated in the study.

"The robust results from our second Phase 3 trial of fidaxomicin confirm the results of our first Phase 3 trial showing that fidaxomicin has the potential to be a first-in-class drug for the treatment of Clostridium difficile infection.  There are currently limited treatment options for this disease and we believe there is a need for innovative alternatives," said Michael N. Chang, Ph.D., Optimer's Chief Executive Officer.  "A higher global cure demonstrates the potential for fidaxomicin to improve patient outcomes, reduce repeat visits to the hospital and reduce person-to-person transmission, which may result in a lower cost burden to the healthcare system."

"The growing incidence of CDI in hospitals, long-term care facilities, and in the community, which we believe is caused in part by the use of broad-spectrum antibiotics and an aging population, create a need for new CDI therapies," said Sherwood L. Gorbach, M.D., Optimer's Chief Medical Officer. "These results show that a single, effective antibiotic can provide a high cure rate and simultaneously, a low recurrence rate.  We believe fidaxomicin demonstrates a clinically significant difference and offers substantial benefits to CDI patients and the medical community."