Cubist Pharmaceuticals Inc has acquired the worldwide rights to CAB-175 from Biochemie GmbH, a unit of Novartis Generics business sector. CAB-175 is a unique investigational cephalosporin antibiotic in late-stage pre-clinical development and has demonstrated in vitro activity against most clinically relevant Gram-positive and Gram-negative bacteria, including important resistant species. Financial terms of the acquisition were not disclosed.

CAB-175 is a new chemical entity belonging to a sub-class of cephalosporins called azomethines. Although cephalosporins now represent roughly one-third of the estimated $23 billion global market for antibiotics, limitations to their use now exist due to the continued emergence of bacterial resistance. For example, currently marketed cephalosporins are not effective against methicillin-resistant Staphylococcus aureus (MRSA) strains, which are estimated to be the cause of approximately 35% of S. aureus infections in the U.S. and up to 42% and 70% of similar infections in parts of Europe and Asia, respectively. CAB-175 has demonstrated in vitro bactericidal (killing) activity against MRSA, and is also active against most other important Gram-positive bacteria, including susceptible and certain multi-drug resistant Pneumococci, Streptococci and Enterococci and virtually all clinically relevant Gram-negative bacteria, including many beta-lactamase-producing strains.

Preliminary pre-clinical animal studies indicate that CAB-175 could have a similar safety profile to ceftriaxone, a drug that has been successfully and safely prescribed for over 15 years in both adults and children. The compound is water soluble, with pharmacokinetics in non-human primates suggesting twice-daily parenteral dosing. Cubist will initially be investigating CAB-175 in an intravenous (IV) formulation, but will also perform feasibility studies on potential intramuscular (IM) and oral dosage formulations. In in vitro studies, CAB-175 has thus far demonstrated a very low potential for the development of bacterial resistance.

If successfully developed, CAB-175 could target hospitalized patient populations suffering from lower and upper respiratory infections, urinary tract infections, intra-abdominal infections, skin and soft tissue infections and febrile neutropenia. These indications represent in excess of 15 million treated patients each year on a global basis. CAB-175 complements well Cubist's current lead investigational antibiotic Cidecin (daptomycin for injection), as commercialization efforts for CAB-175 and Cidecin would target a similar physician audience, should they both ultimately gain regulatory approval.