In two Phase 3 trials for the treatment of CDI, fidaxomicin was non-inferior in clinical cure when compared to vancomycin, the only FDA approved product for CDI.
The first analysis aimed to identify risk factors associated with early recurrence (a relapse within the first two weeks after end of therapy) compared to late recurrence (a relapse during the third and fourth weeks after end of therapy).
The University of Chicago Department of Medicine associate professor Kathleen Mullane said the data from this study demonstrate that patients treated with fidaxomicin were less likely to suffer a relapse of the initial infection within the first two weeks after completing therapy.
"The data also suggest that late recurrence is likely due to a reinfection from the environment, particularly in patients with risk factors such as elevated white blood cells and low albumin levels at the end of therapy and exposure to concomitant antibiotics," Mullane said.
Data from the second trial demonstrated that DIFICID is minimally absorbed with plasma levels in the low ng/mL range while maintaining high fecal concentration that are well in excess of the MIC90 versus C. difficile.
The analysis measured the concentration of DIFICID and its metabolite, OP-1118, in the plasma and feces of patients treated with the drug in the Phase 3 clinical studies.
Optimer Biology and Pre-Clinical Science executive director Pam Sears said following oral administration, DIFICID has minimal systemic exposure, even in patients with CDI and the data show that DIFICID tends to stay in the site of infection for this disease.