Genzyme Corp. announced top-line data from the first of two Phase 3 clinical studies to assess the safety and efficacy of tolevamer liquid, an investigational, non-antibiotic, polymer therapy for patients with Clostridium difficile associated diarrhea (CDAD). The second Phase 3 study of tolevamer liquid is fully enrolled and results are expected later this year.
In this first Phase 3 study known as the Polymer Alternative for CDAD Treatment (PACT) study, tolevamer liquid did not meet its primary endpoint of non-inferiority to the standard prescribed oral dose of the antibiotic vancomycin, as measured by the percent of patients with resolution of CDAD. This result contrasts with the findings from Genzyme's earlier Phase 2 study of a solid oral dosage formulation of tolevamer that met its primary endpoint of non-inferiority compared to vancomycin.
Consistent with recent published studies, high rates of CDAD recurrences were observed in patients treated with either vancomycin or metronidazole. High CDAD recurrence rates were not observed in patients treated with tolevamer liquid. Tolevamer liquid was generally well tolerated with no unanticipated safety concerns. Data from this first Phase 3 study is expected to be presented at a future medical conference.
"These are disappointing results that alter our expectations about the potential for commercializing tolevamer in the near future," stated Henri A. Termeer, chairman and chief executive officer of Genzyme Corp. "The results of our second Phase 3 study will be available later this year and will help us determine what contribution tolevamer might be able to make in addressing this serious unmet medical need."
C. difficile has become one of the most significant infection control concerns in healthcare today. Physicians worldwide are confronting a worsening epidemic, with an alarming rise in the incidence of disease, higher numbers of patients with complications and more frequent failures of standard antibiotic therapy.
Tolevamer is designed to bind and neutralize the toxins released by C. difficile that damage the intestine. A non-antibiotic approach has the potential to treat CDAD and reduce the number of disease recurrences, resulting in improved quality of life for the patient and significant savings to the healthcare system.