Optimer reports positive results from Phase III CDI study

In this multi-center, randomized, double-blind Phase III clinical trial, 629 adult subjects were enrolled. Subjects with confirmed Clostridium difficile infection (CDI) received either 200mg OPT-80 dosed orally twice daily or 125mg Vancocin dosed orally four times daily.

This study was conducted in more than 100 clinical sites throughout North America. The objective of the study was to show that a 10-day course of OPT-80 was at least as efficacious and safe as a 10-day course of Vancocin for the treatment of CDI. The primary endpoint of the study was clinical cure defined as patients requiring no further CDI therapy two days after completion of study medication, as determined by the investigator.

The secondary endpoint evaluated CDI recurrence up to four weeks post therapy with recurrence defined as the return of diarrhea associated with CDI confirmed by a positive toxin test. Global cure, an exploratory endpoint, was defined as patients who were cured and did not have a recurrence.

Approximately 92.1% of patients treated with OPT-80 (per protocol population) has achieved clinical cure versus 89.8% for Vancocin. In addition, only 13.3% of patients treated with OPT-80 experienced a recurrence versus 24% for Vancocin (p = 0.004). Patients treated with OPT-80 had a global cure (cure with no recurrence within four weeks) of 77.7%, which was greater than Vancocin at 67.1% (p = 0.006). OPT-80 was well-tolerated, the company said.

Michael Chang, CEO of Optimer, said: “I believe OPT-80 will be an important therapeutic option for CDI, an infection that currently has limited treatment options and affects more than 500,000 patients in the US annually with growing incidence worldwide. Our next step is to complete the on-going second Phase III study at clinical sites in Europe and North America to support an new drug application filing.”