ALAMEDA, CA --  Cerexa Inc. announced a formal agreement for its acquisition by Forest Laboratories (NYSE: FRX) for $480 million in cash plus up to $100 million in a milestone payment.

Forest is acquiring Cerexa for its Ceftaroline drug, a promising antibiotic in late stage clinical trials, and other promising candidates.

Investors in Cerexa were Canaan Partners, OrbiMed Advisors, Frazier Healthcare Ventures, New Leaf Venture Partners, Pappas Ventures, Montreux Equity Partners, EGS Healthcare Capital Partners and Sears Capital Management.