The U.S. Food and Drug Administration (FDA) has approved Optimer Pharmaceuticals’ antibacterial drug DIFICID (fidaxomicin) tablets for the treatment of Clostridium difficile-associated diarrhea (CDAD) in adults 18 years of age and older. In the largest Phase 3 clinical studies ever conducted in CDAD, DIFICID had clinical response rates at the end of treatment that were non-inferior to oral vancomycin. DIFICID was superior to vancomycin in sustaining clinical response through 25 days beyond the end of treatment. DIFICID is the only FDA-approved antibacterial drug proven to be superior to vancomycin in sustained clinical response for CDAD.
“The FDA approval of DIFICID is the culmination of Optimer’s efforts to develop an innovative therapy for the treatment of CDAD,” said Pedro Lichtinger, president and chief executive officer of Optimer. “The clinical development program for DIFICID was designed to address one of the greatest challenges in managing CDAD, disease recurrence. We are proud to provide the medical community and patients with an effective treatment proven to produce sustained clinical response in CDAD, and are now moving into the commercialization stage where we will partner with physicians and health systems to ensure that DIFICID reaches patients in urgent need of an important new treatment option. The recognition in our label of the DIFICID superiority in sustained clinical response will allow the Optimer and Cubist field force to educate the medical community about the advantage DIFICID can offer to appropriate CDAD patients.”
“The incidence and severity of CDAD has increased dramatically in the U.S. in the past decade and is continuing to rise each year,” said Sherwood Gorbach, MD, chief scientific officer and senior vice president. “DIFICID is an important new first-line treatment option for patients who may be most at-risk of disease recurrence, for whom producing a sustained clinical response is critical. Patients who are elderly, those exposed to concomitant antibiotics and patients whose immune systems have been compromised are at increased risk, and the majority of patients who will experience a disease recurrence after their first episode of CDAD do so within the first few weeks after treatment.”
The approval of DIFICID was based on results from two randomized, multi-center, double-blinded trials. A non-inferiority design was utilized to demonstrate the efficacy of DIFICID (200 mg orally twice daily for 10 days) compared to vancomycin (125 mg orally four times daily for 10 days) in adults with CDAD. The studies enrolled a total of 1,164 adults with confirmed CDAD.
The primary objective of both studies was to show that a 10-day course of DIFICID was as effective as oral vancomycin in achieving a clinical response at the end of therapy. An additional efficacy endpoint was sustained clinical response, defined as clinical response at the end of treatment and survival without proven or suspected CDAD recurrence through 25 days beyond the end of treatment.
In the first trial, conducted in North America, 88% of patients who received DIFICID experienced a clinical response at the end of therapy compared to 86% of vancomycin-treated patients. Results for clinical response at the end of therapy were consistent in the second trial, which was conducted in North America and Europe. Sustained clinical response 25 days after the end of treatment was 70% for DIFICID-treated patients in the first trial and 72% for DIFICID-treated patients in the second trial, compared to 57% in both trials for vancomycin-treated patients.
Release Date: May 27, 2011
Source: Optimer Pharmaceuticals, Inc.
Filed Under: Drug Discovery