Optimer, Cubist sign deal to market DIFICID for CDI treatment in the U.S.

Optimer Pharmaceuticals, Inc. (NASDAQ: OPTR) and Cubist Pharmaceuticals, Inc. (NASDAQ: CBST) today announced the signing of an exclusive two-year co-promotion agreement to market DIFICID™ (fidaxomicin), in the United States.  DIFICID is a novel antibiotic currently being reviewed for market approval by the FDA for the treatment of Clostridium difficile infection (CDI), which is also known as Clostridium difficile-associated diarrhea (CDAD).  On April 5, 2011, the FDA's Anti-Infective Drugs Advisory Committee voted unanimously that the clinical evidence submitted by Optimer demonstrated the safety and effectiveness of DIFICID for the treatment of CDI, thereby recommending approval of DIFICID as a treatment for CDI. The FDA is expected to complete its review of DIFICID and deliver a decision on market approval by a Prescription Drug User Fee Act (PDUFA) goal date of May 30, 2011.

Under the terms of the agreement, Optimer and Cubist will co-promote DIFICID to physicians, hospitals, long-term care facilities and other healthcare institutions in the United States. Optimer and Cubist will also jointly provide medical affairs support for the product. Optimer plans to strategically build its sales force and medical affairs team.  Optimer's team will be complemented by Cubist's existing U.S. hospital sales force and medical affairs team which is already dedicated to the antibiotic space for CUBICIN® (daptomycin for injection), Cubist's therapy for Staphylococcus aureus bacteremia, including right-sided endocarditis, and complicated skin infections caused by certain Gram-positive bacteria, including MRSA.

"Cubist has a proven track record and well established relations with all stakeholders involved in the antibiotics space.  We believe this collaboration will maximize the impact of and de-risk DIFICID's U.S. commercial launch, assuming approval," said Pedro Lichtinger, President and CEO of Optimer.  "Optimer plans to hire 100 sales representatives to target the 1,100 hospitals, which comprise about 70% of U.S. hospital CDI cases.  We also believe this collaboration with Cubist will allow us to accelerate formulary adoption, expand our market reach and penetration to up to 2,000 hospitals, comprising over 90% of U.S. hospital CDI cases, and commit resources to long-term care facilities that comprise approximately one-third of all CDI cases.  In addition, this provides the opportunity to capture the undiagnosed CDI market segment which some estimate to be as many as three million cases per year."

Cubist's President and CEO Michael Bonney said, "We believe that the strengths of Cubist's seasoned sales force, medical affairs team and our experience in the hospital will add tremendous value to Optimer's launch strategy and execution. We look forward to working with Optimer to introduce a much needed therapy for seriously ill patients suffering from CDAD."

The agreement expires two years from the first commercial sale of DIFICID.  The agreement can be renewed for additional terms upon agreement of the parties and can be terminated early by either party in certain defined situations. Optimer will be responsible for the manufacturing and distribution of DIFICID in the United States and for recording product revenue.  Optimer will be responsible for obtaining FDA approval, and will retain ownership of the New Drug Application.  For its efforts under the co-promotion agreement, including providing specified levels of resources and activities, Cubist will receive quarterly service fees of $3.75 million ($15 million per year) over the two years beginning with the first commercial sale of DIFICID. Cubist is also eligible to receive an additional $5 million in the first year after first commercial sale and $12.5 million in the second year of the agreement if mutually agreed upon annual sales targets are achieved, as well as a portion of Optimer's gross profits from any sales above the specified annual sales target levels.