Cosmo pharmaceuticals


Rifamycin SV MMX® (U.S. brand name: Aemcolo®) is a pharmaceutical drug product in form of tablets containing rifamycin SV formulated with the MMX® technology. Rifamycin SV MMX® contains a broad spectrum, semi-synthetic, orally non-absorbable antibiotic, and has been approved in the US and in the EU for the treatment of traveler’s diarrhea caused by non-invasive E. coli strains.  

The application of MMX® technology to rifamycin SV allows the antibiotic to be delivered directly into the colon, avoiding unwanted effects on the beneficial bacterial flora living in the upper portions of the gastro-intestinal tract. The specific dissolution profile of Aemcolo® tablets increases the colonic concentration of the antibiotic so that an optimized pharmacological effect is achieved in the target organ.  

In the US it is currently licensed to Cosmo’s partner RedHill Biopharma under the brand name Aemcolo® (containing 200 mg of rifamycin sodium, equivalent to 194 mg of rifamycin).   

In September 2023, Cosmo announced the termination by mutual agreement of the license with Dr. Falk Pharma for Rifamycin SV MMX® in the EU and other selective countries and announced the signing of a new license and supply agreement with Adalvo Ltd. in Europe, Asia-Pacific (APAC), Middle East/North Africa (MENA) and Latin America (LATAM) regions.  Adalvo will take the lead in obtaining approvals for Rifamycin SV MMX® in the Asia-Pacific (APAC), Middle East/North Africa (MENA) and Latin America (LATAM) regions, as well as selected European countries, extending the reach of this innovative treatment to a broader global audience.  

In a randomized, double-blind, placebo-controlled phase 3 study of adult travelers to Mexico or Guatemala experiencing acute diarrhea, the primary endpoint was met with high statistical significance: patients who were randomized to Rifamycin SV MMX® had a significantly shorter time between the administration of the first dose and the passage of the last unformed stool (Time to Last Unformed Stool, abbrev. TLUS) as compared to placebo (median TLUS 46.0 hours vs 68.0 hours, respectively; p = 0.0008). Additionally, a larger percentage of Rifamycin SV MMX® treated patients (81.4%) achieved clinical cure compared with placebo patients (56.9%). Full study results are described in DuPont et al. International Society of Travel Medicine, 1195-1982 Journal of Travel Medicine 2014; Volume 21 (Issue 6): 369–376. 

In another randomized, double-blind, double-dummy phase 3 study the efficacy of Rifamycin SV MMX® (400 mg BID) was compared to ciprofloxacin (500 mg BID) in the treatment of traveller’s diarrhea. The primary endpoint of the study, i.e., the time to last unformed stool (TLUS) after which clinical cure was declared, was met, and Rifamycin SV MMX® was found to be non-inferior to ciprofloxacin (p=0.0035). Secondary efficacy endpoint results including clinical cure rate, treatment failure rate, requirement of rescue therapy as well as microbiological eradication rate confirmed those of the primary analysis indicating equal efficacy for both compounds. While patients receiving ciprofloxacin showed a significant increase of Extended Spectrum Beta Lactamase Producing—Escherichia coli (ESBL-E. Coli) colonization rates after 3-days treatment (6.9%), rates did not increase in patients receiving RIF-MMX (−0.3%). Extended-spectrum beta-lactamases (ESBL) are enzymes that confer resistance to most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam, also including many fourth generation cephalosporins. Full study results are published in R. Steffen et al., Journal of Travel Medicine, 2018, 1–11. 

The results of the second phase 3 study of Rifamycin MMX, showing a lack of effect of such antibiotic on ESBL-producing E. coli, provides an important advantage in view of the recent concerns regarding the emergence of multi-drug resistant bacteria, whose infections are challenging to be treated. 

A full evaluation of Rifamycin 200 mg MMX was independently published by the ADIS Drug Review progra in Clinical Drug Investigation (2019). 39: 691-697.

The product has also shown an excellent safety profile, both in toxicology and in clinical studies.  

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