Santarus, Inc, a specialty biopharmaceutical company, has submitted an Investigational New Drug (IND) application to the US Food and Drug Administration (FDA) requesting approval to begin a phase-III clinical programme evaluating rifamycin SV MMX in patients with travellers' diarrhoea.

In the IND, Santarus proposed two international multi-centre, randomized, double-blind studies, each with approximately 300 patients, to assess the efficacy and safety of rifamycin SV MMX 400 mg (2 x 200 mg) oral tablets taken twice daily (800 mg total daily dose) for three days versus placebo in the treatment of patients with travellers' diarrhoea. The primary endpoint of the phase-III clinical studies will be the time to last unformed stool (TLUS) and the studies will seek to demonstrate the superiority of rifamycin SV MMX to placebo.

Santarus expects to begin the first phase-III study in the first half of 2010. Assuming timely and successful completion, Santarus plans to initiate a second phase-III clinical study in travellers' diarrhoea in the first half of 2011.

Santarus has licensed exclusive rights to develop and commercialize rifamycin SV MMX in the US from Cosmo Technologies Limited, a wholly owned subsidiary of Cosmo Pharmaceuticals SpA. Cosmo conducted the rifamycin SV MMX phase-II clinical programme, which consisted of two studies in a total of 155 patients with infectious diarrhoea in Mexico, Turkey and South Africa, under Clinical Trial Applications with regulatory authorities in those countries.

Based on a pre-IND meeting in early 2009, the US FDA determined that rifamycin SV MMX is a new molecular entity (NME) in the US and requested a full preclinical assessment prior to submitting an IND. These preclinical studies have recently been completed, allowing Santarus to proceed with the submission of the IND.

"The filing of the IND is an important milestone in the rifamycin SV MMX clinical program, and we look forward to moving forward with the development of rifamycin SV MMX for patients with travellers' diarrhoea," said Gerald T Proehl, president and chief executive officer.

Rifamycin SV MMX is a broad spectrum, semi-synthetic antibiotic with negligible systemic absorption that also has targeted release characteristics when taken orally. The application of MMX technology to rifamycin SV allows the antibiotic to be delivered directly to the colon, optimizing drug levels in the colon where the pathogens of travellers' diarrhoea are predominant. In addition to the targeted drug delivery, the company believes the negligible absorption of rifamycin SV MMX will offer an opportunity for limited side effects.

Cosmo's European partner, Dr Falk Pharma GmbH, is planning to initiate in the first half of 2010 a phase-III clinical study in patients with travellers' diarrhea for registration of rifamycin SV MMX in the European Union (EU). The Dr Falk phase-III study will assess the efficacy (non-inferiority) and safety of rifamycin SV MMX 400 mg (2 x 200 mg) oral tablets taken twice daily (800 mg total daily dose) for three days versus ciprofloxacin 500 mg tablets twice daily (1,000 mg total daily dose) in the treatment of patients with travellers' diarrhoea. Assuming successful completion of the phase-III clinical programme, Santarus and Dr Falk plan to share their clinical data for inclusion in each company's respective regulatory submissions.

The MMX technology consists of a sequence of lipophilic and amphiphilic matrices dispersed within a hydrophilic matrix.

Santarus is a specialty biopharmaceutical company focused on acquiring, developing and commercializing proprietary products that address the needs of patients treated by gastroenterologists and other physicians.