Optimer Pharma Releases Top-line Results From Second Fidaxomicin Phase 3 Trial

In the trial, Fidaxomicin met the primary endpoint of non-inferiority in clinical cure compared to Vancocin. Fidaxomicin also had lower recurrence rates compared to Vancocin and significantly higher global cure rates compared to Vancocin.

Optimer Pharmaceuticals said that the results from the second Fidaxomicin Phase 3 trial confirm the results from the first Fidaxomicin Phase 3 trial. Together these trials enrolled more than 1,100 subjects thus making them the two largest comparative studies ever conducted against Vancocin in CDI.

Additional data presented were included a subgroup analysis of the BI/NAP1/027 strain and the non-BI/NAP1/027 strain showing clinical cure, recurrence and global cure rates for Fidaxomicin compared to Vancocin.

Most notably, Fidaxomicin showed a clinically meaningful reduction in recurrence rates and higher global cure rates compared to Vancocin in both strain type subgroups. Clinical cure rates for Fidaxomicin and Vancocin were similar in these two strain type subgroups.

In the trial, BI/NAP1/027 strain was identified in 32% of subjects in the second Phase 3 study. 54% of the study participants were over the age of 65, 68% were in-patients, and 15% had a prior episode of CDI. An average of 7.5 bowel movements per day was observed among all subjects.

Crook, consultant microbiologist/infectious diseases and professor of infectious diseases and microbiology of experimental medicine division for nuffield department of clinical medicine (NDM) at University of Oxford, said: “Fidaxomicin offers potential advantages over existing therapies as a single agent that can provide a high cure rate and fewer recurrences for Clostridium difficile infection. Moreover, we found that even in patients with the hypervirulent BI/NAP1/027 subtype, Fidaxomicin provided an improvement in recurrence rates compared to the currently approved treatment.”