NEW YORK ( The Deal) -- Cubist Pharmaceuticals ( CBST) on Tuesday committed up to $1.6 billion to acquire two makers of next-generation antibiotics in a bid to expand aggressively its acute care product portfolio. Lexington, Mass.-based Cubist said it would pay up to $818 million for Trius Therapeutics ( TSRX) and up to $801 million for Optimer Pharmaceuticals ( OPTR), should all milestone payments be achieved. The deals would add between $600 million and $1 billion in annual sales to Cubist, already a major manufacturer of antibiotics. Terms of the Trius deal call for Cubist to pay $13.50 per share in cash for total consideration of $707 million. Each Trius holder will also receive one contingent value right that would entitle the holder to an additional cash payment of up to $2 per share should commercial sales targets be achieved, which could add another $111 million in value. Cubist will also pay $10.75 per share in cash for Optimer, valuing the company at $535 million, and will issue a contingent value right that could provide Optimer investors with an additional $5 per share should targets be met. San Diego-based Trius is developing a late-stage antibiotic candidate that it hopes will be effective against drug-resistant bacteria. The company has partnered with Bayer Pharma AG for development and commercialization of its lead compound outside of the U.S., Canada and the European Union, and hopes to submit a request for approval of the drug to the U.S. Food and Drug Administration before year's end. Cubist CEO Michael Bonney said in a statement, "Trius is a tremendous strategic fit with Cubist that supports our Building Blocks of Growth long-range goals while extending our global leadership in the acute care environment." Under the terms of the deal Trius shareholders would receive $1 per share in additional payment should net sales of Trius products equal or better $125 million in 2016, and up to an additional $1 per share on a pro rata basis for 2016 net sales between $125 million and $135 million. Optimer, of Jersey City, N.J., has been reviewing options since a February announcement that it was replacing its CEO. The company already has a deal in place to co-promote its antibacterial drug Dificid, which is used to treat diarrhea, with Cubist. Bonney called Optimer "a natural fit" given their existing relationship.