Positive results from Santarus rifamycin SV MMX Phase III study on travelers' diarrhea

Santarus, Inc. (NASDAQ: SNTS) today announced that its Phase III clinical study to evaluate the safety and efficacy of the investigational drug, rifamycin SV MMX^®, met the primary endpoint of reducing time to last unformed stool (TLUS) in patients with travelers' diarrhea.    

In the intent-to-treat (ITT) population (n=264), the median TLUS was 46.0 hours for rifamycin SV MMX (n=199) compared with 68.0 hours for placebo (n=65), p = 0.0008. Results in the per protocol population (n=240) were similar to the ITT population.   

Rifamycin SV MMX was generally well tolerated in this Phase III clinical study and the frequency of treatment emergent adverse events was similar to placebo. The most frequent treatment emergent adverse events experienced by ≥ 2% of patients in either treatment group were: headache (8.0% in active arm and 9.2% in the placebo arm), diarrhea (5.0% in the active arm and 9.2% in the placebo arm), infectious diarrhea (5.0% in the active arm and 7.7% in the placebo arm), constipation (3.5% in the active arm and 1.5% in the placebo arm), amoebic dysentery (0% in the active arm and 3.1% in the placebo arm) and gastrointestinal infection (0% in the active arm versus 3.1% in the placebo arm). There were three patients who experienced serious adverse events, all of which were assessed by the investigator as not related to the study drug. One patient in the placebo group developed clostridium difficile colitis and two patients in the rifamycin SV MMX group experienced a total of three adverse events: neuroblastoma, abdominal pain and vomiting. Santarus expects additional data from this clinical study will be presented at an appropriate medical meeting in 2013.

Santarus licensed rights to develop and commercialize rifamycin SV MMX in the U.S. from Cosmo Technologies Limited. Dr. Falk Pharma GmbH, Cosmo's European development partner, is conducting a second Phase III clinical study to evaluate the efficacy of rifamycin SV MMX versus ciprofloxacin with the primary endpoint of TLUS in patients with travelers' diarrhea. This non-inferiority study is expected to enroll approximately 1,000 patients and to be completed in mid-2013. Assuming positive results in the second Phase III clinical study, Santarus and Dr. Falk plan to share the clinical data from their respective Phase III studies for inclusion in each company's regulatory submissions.

"These favorable Phase III results in travelers' diarrhea represent a significant positive milestone in the clinical development of rifamycin SV MMX for the U.S. market. Rifamycin SV is an investigational broad spectrum, non-systemic antibiotic that has been used for more than 20 years in Europe in both intravenous and intramuscular forms, but is considered a new chemical entity in the U.S.," said Wendell Wierenga, Ph.D., executive vice president, research and development of Santarus. "As we wait for completion of the second ongoing Phase III study being conducted by Dr. Falk Pharma, we plan to assess our options to evaluate rifamycin SV MMX in other indications where a non-systemic antibiotic with a broad spectrum of activity may offer a clinical benefit."