Optimer Launches DIFICID™ (fidaxomicin) Tablets for Treatment of Clostridium Difficile-Associated Diarrhea (CDAD) in Patients 18 Years of Age and Older

SAN DIEGO, July 18, 2011 /PRNewswire/ -- Optimer Pharmaceuticals, Inc. (NASDAQ: OPTR) today announced the commercial launch of DIFICID™ (fidaxomicin) tablets for the treatment of Clostridium difficile-associated diarrhea (CDAD) in patients 18 years of age and older. In two large Phase 3 clinical studies, DIFICID had clinical response rates at the end of the 10-day treatment period that were non-inferior to oral vancomycin. In addition, DIFICID was superior to vancomycin in sustained clinical response, defined as clinical response at the end of treatment and survival without proven or suspected CDAD recurrence through 25 days beyond the end of treatment. With the commercial availability of DIFICID, Optimer is initiating a Patient Assistance Program to help eligible uninsured and underinsured patients gain access to this important treatment option. DIFICID is the only FDA-approved treatment for CDAD that has demonstrated superiority to vancomycin in sustained clinical response and the first new drug approved for the treatment of CDAD in more than 25 years.

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"Patient access to DIFICID is Optimer's highest priority. For eligible patients, the Patient Assistance Program will help expand access to DIFICID for those patients in need," said Pedro Lichtinger, President and Chief Executive Officer of Optimer. "We have assembled a world class hospital-based product launch team in the U.S., including expertise in access, reimbursement, health economics, medical education, sales and marketing that we believe when combined with Cubist, our co-promotion partner in the U.S., will make the DIFICID launch one of the most impactful in the hospital segment. This team will help bring to patients a new option proven to provide superior sustained clinical response."

More information on the Optimer Patient Assistance Program, including eligibility guidelines, can be accessed from Optimer's website at http://www.optimerpharma.com. Patients also can call (855) 841-4236 between the hours of 8 a.m. and 8 p.m. Eastern Daylight Time (EDT), Monday through Friday to complete the phone application process.

"CDAD can be devastating. The initial disease can be serious, even life-threatening, and about 20 to 30% may have a recurrence. In some cases, patients have many recurrences. Any treatment that can provide a sustained clinical response is an important advance," said John Bartlett, M.D., Stanhope Bayne Jones Professor of Medicine and Chief of the Division of Infectious Diseases at The Johns Hopkins University School of Medicine.

Optimer also has filed a Marketing Authorization Application (MAA) with the European Medicines Agency (EMA) for approval of fidaxomicin, and has entered into an exclusive collaboration and license agreement with Astellas Pharma Europe Ltd. to develop and commercialize the drug in Europe and certain other countries.

Important Safety Information about DIFICID

DIFICID should not be used for systemic infections. Only use DIFICID for infection proven or strongly suspected to be caused by C. difficile.

The most common adverse reactions are nausea (11%), vomiting (7%), abdominal pain (6%), gastrointestinal hemorrhage (4%), anemia (2%) and neutropenia (2%).

For full prescribing information for DIFICID, please call 1-855-DIFICID (1-855-343-4243) or visit www.DIFICID.com.

About CDAD

Clostridium difficile-associated diarrhea (CDAD) has become a significant medical problem in hospitals, long-term care facilities and in the community. CDAD is a serious illness resulting from infection of the inner lining of the colon by C. difficile bacteria, which produce toxins that cause inflammation of the colon, severe diarrhea and, in the most serious cases, death. Patients typically develop CDAD from the use of broad-spectrum antibiotics that disrupt normal gastrointestinal (gut) flora, possibly allowing C. difficile bacteria to flourish. Older patients in particular are at risk for CDAD, potentially because of a weakened immune system or the presence of underlying disease. Approximately two-thirds of CDAD patients are 65 years of age or older.

Current estimates suggest CDAD may affect more than 700,000 people in the U.S. each year, though the incidence may be higher as many cases are believed to be undiagnosed, untreated and underreported. The disease adds significant costs and burden to the U.S. healthcare system with estimates for medical treatment and hospital stays associated with CDAD reaching as much as $3.8 billion every year. Historically, approximately 20% to 30% of CDAD patients who initially respond to treatment experience a clinical recurrence.

About DIFICID™ (fidaxomicin) Tablets

DIFICID is the first antibacterial drug indicated for CDAD to be approved in more than 25 years. It is indicated for the treatment of CDAD in adults 18 years of age or older. DIFICID is administered in 200 mg tablets given orally twice daily. In two large Phase 3 clinical studies DIFICID had a clinical response rate at the end of the 10-day treatment period that was non-inferior to oral vancomycin. DIFICID demonstrated superior sustained clinical response, defined as clinical response at the end of treatment and survival without proven or suspected CDAD recurrence through 25 days beyond the end of treatment, compared to oral vancomycin. This difference was due to lower rates of proven or suspected CDAD during the follow-up period in DIFICID-treated patients. Similar rates of clinical response at the end of treatment and proven or suspected CDAD during the follow-up period were seen in DIFICID-treated and vancomycin-treated patients infected with a BI isolate.

DIFICID should not be used for systemic infections. Only use DIFICID for infection proven or strongly suspected to be caused by C. difficile. The most common adverse reactions are nausea (11%), vomiting (7%), abdominal pain (6%), gastrointestinal hemorrhage (4%), anemia (2%), and neutropenia (2%).

About Optimer

Optimer Pharmaceuticals, Inc. is a biopharmaceutical company focused on discovering, developing and commercializing innovative hospital specialty products that have a positive impact on society. Optimer has developed and commercialized DIFICID™ (fidaxomicin) tablets, an FDA-approved antibacterial drug for the treatment of adult patients with Clostridium difficile-associated diarrhea (CDAD). Optimer has filed a marketing authorization application with the European Medicines Agency for fidaxomicin. Optimer's clinical pipeline includes Pruvel™, a product in the fluoroquinolone class of antibiotics that has completed Phase 3 trials as a treatment for infectious diarrhea. Additional information can be found at http://www.optimerpharma.com.

Forward Looking Statements

Statements included in this press release that are not a description of historical facts are forward-looking statements, including without limitation statements related to Optimer's plans to commercialize DIFICID, including with its co-promotion partner, the incidence of CDAD, the ability of Optimer's Patient Assistance Program to expand access to DIFICID, and Optimer's expectations regarding the impact of the commercial launch of DIFICID. Words such as "believes", "would", "anticipates", "plans", "expects", "may", "intend", "will", and similar expressions are intended to identify forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation by Optimer that any of its plans will be achieved. These forward-looking statements are based on management's expectations on the date of this release. Actual results may differ materially from those set forth in this release due to the risks and uncertainties inherent in Optimer's business including, without limitation, risks relating to: the implementation and continuation of Optimer's co-promotion agreement with Cubist, Optimer's and Cubist's ability to commercialize DIFICID according to Optimer's expected scope and timelines, Optimer's ability to successfully implement and manage its Patient Assistance Program, the ability of Optimer and its third party contractors to manufacture and supply sufficient quantities of DIFICID in accordance with Good Manufacturing Practices to meet demand, whether healthcare professionals will prescribe DIFICID, whether DIFICID will receive reimbursement coverage from healthcare payors and government agencies, the extent to which DIFICID will be accepted on hospital formularies, Optimer's ability to successfully manage a sales and marketing organization and other risks detailed in Optimer's filings with the Securities and Exchange Commission.

Contacts
Optimer Pharmaceuticals, Inc.
David Walsey, Vice President, Investor Relations and Corporate Communications
858-909-0736

Canale Communications, Inc.
Jason I. Spark, Senior Vice President
619-849-6005

SOURCE Optimer