Cubist Pharmaceuticals has agreed to pay $92.5 million in cash to acquire anti-infectives firm Calixa Therapeutics. Calixa stockholders could also share out another $310 million worth of development, regulatory, and commercial milestones relating to products incorporating CXA-101, a cephalosporin antibiotic against multidrug-resistant P. aeruginosa.
Calixa acquired global development rights excluding certain Asia-Pacific territories to CXA-101 from Astellas Pharma in 2007. The company has already successfully completed two Phase I trials with CXA-101, and a Phase II study was initiated in June in patients with complicated urinary tract infections (cUTIs).
CXA-101 is also being studied together with tazobactam, a beta-lactamase inhibitor. The combination product, called CXA-102, is in development against serious Gram-negative bacterial infections. Also in the pipeline is CXA-301, an inhaled formulation of CXA-101 for use in cystic fibrosis patients.
Cubist says if the merger with Calix goes through, it anticipates pushing on with development of CXA-201 against cUTIs and complicated intra-abdominal infections during the first half of 2010. The company also expects to start clinical trials with CXA-201 against nosocomial pneumonia during the second half of 2010.
Cubist believes that CXA-201 will complement Cubicin®, its marketed drug for the treatment of complicated skin infections and bacteremia caused by MRSA. Cubicin was first launched in the U.S. in 2003 and remains Cubist’s main revenue driver. The drug made total worldwide revenues of $143.5 million during the third quarter, up from $130.8 million in the second quarter. The company projects that sales of Cubicin will top $1 billion annually in the U.S. alone.