Press releases

Baxter BioScience and Merrimack Pharmaceuticals Announce Filing for European Approval of MM-398, an Investigational Treatment for Post-Gemcitabine Metastatic Pancreatic Cancer

Filing Based on Positive Phase 3 Data Suggest Survival Benefit in Deadly Disease

DEERFIELD, Ill. and CAMBRIDGE, Mass., May 4, 2015 - Baxter International Inc. (NYSE:BAX) and Merrimack Pharmaceuticals, Inc. (Nasdaq:MACK) jointly announced that Baxter has submitted a marketing authorization application (MAA) to the European Medicines Agency (EMA) for approval of MM-398 (irinotecan liposome injection), also known as "nal-IRI," an investigational treatment for patients with metastatic adenocarcinoma of the pancreas who have been previously treated with gemcitabine-based therapy. The submission follows Merrimack's recent filing of a new drug application (NDA) for this indication with the United States Food and Drug Administration (FDA).

"Our coordinated U.S. and EU filings illustrate our strong commitment to actively advancing this joint program and our desire to provide patients who are fighting pancreatic cancer with a new therapeutic option," said David Meek, head of Oncology at Baxter BioScience. "MM-398 is an important asset in our oncology portfolio that will be investigated for other cancers where there remains unmet medical need."

Both the U.S. and European submissions were based on the positive results of the international Phase 3 NAPOLI-1 study, which was conducted among patients with metastatic pancreatic cancer who previously received gemcitabine-based therapy. MM-398 in combination with 5-fluorouracil (5-FU) and leucovorin (LV) achieved its primary and secondary endpoints by demonstrating a clinically and statistically significant improvement in overall survival, progression free survival and overall response rate compared to the control group of patients who received a combination of 5-FU and LV. The most common Grade 3 or higher adverse events in patients receiving MM-398 and 5-FU/LV were neutropenia, fatigue and gastrointestinal effects. This was the first global Phase 3 study in a post-gemcitabine setting to show a survival benefit in this aggressive disease. The data were presented in June 2014.

"This submission represents significant progress in our collaborative efforts to deliver MM-398 as a new treatment option to pancreatic cancer patients across the globe," said Robert Mulroy, President and CEO at Merrimack. "We look forward to working together as we move through the US and EU regulatory processes as well as additional submissions around the world."

About MM-398
MM-398 (irinotecan liposome injection), also known as "nal-IRI," is a novel encapsulation of irinotecan in a long-circulating nanoliposomal formulation. The activated form of irinotecan is SN-38, which functions by inhibiting topoisomerase I (an essential enzyme involved in DNA transcription and replication) and promoting cell death.

Merrimack and Baxter International's biopharmaceutical business entered into an exclusive licensing agreement in September 2014 to develop and commercialize MM-398 outside of the United States. PharmaEngine, Inc. (Taipei, Taiwan) holds the rights to commercialize MM-398 in Taiwan.

About Pancreatic Cancer1,2
Pancreatic cancer is rare and deadly, accounting for only three percent of all cancer cases worldwide but is the fourth leading cause of cancer death. An estimated 140,000 new cases are diagnosed every year around the world,
two-thirds of which are among people aged 65 or older. Because the signs and symptoms of pancreatic cancer are non-specific and may not appear until the disease has spread to other sites, approximately 80% of patients are diagnosed with late stage disease. These patients are not candidates for surgery, instead receiving chemotherapy as the mainstay of their therapy. This contributes to the five year survival rate for all patients being less than six percent; fewer than 20 percent of newly diagnosed patients survive more than two years. There is no consensus on the standard of care for patients with metastatic pancreatic cancer previously treated with a gemcitabine-based therapy.

About Baxter International Inc.
Baxter International Inc., through its subsidiaries, develops, manufactures and markets products that save and sustain the lives of people with hemophilia, immune disorders, cancer, infectious diseases, kidney disease, trauma and other chronic and acute medical conditions. As a global, diversified healthcare company, Baxter applies a unique combination of expertise in medical devices, pharmaceuticals and biotechnology to create products that advance patient care worldwide.

About Merrimack Pharmaceuticals
Merrimack is a biopharmaceutical company discovering, developing and preparing to commercialize innovative medicines paired with companion diagnostics for the treatment of cancer. Merrimack seeks to gain a deeper understanding of underlying cancer biology through its systems biology-based approach and develop new insights, therapeutics and diagnostics to improve outcomes for cancer patients. Merrimack has multiple oncology therapeutics in clinical development and additional candidates in late stage preclinical development. Merrimack has submitted a New Drug Application for its lead product candidate, MM-398, for the treatment of patients with metastatic adenocarcinoma of the pancreas who have been previously treated with gemcitabine-based therapy. For more information, please visit Merrimack's website at www.merrimackpharma.com or connect on Twitter at @MerrimackPharma.

Forward-Looking Statement
This release includes forward-looking statements concerning MM-398 and the related collaboration between Baxter International Inc. and Merrimack Pharmaceuticals, Inc., including expectations with regard to regulatory filings and potential impact to patients. The statements are based on assumptions about many important factors, including the following, which could cause actual results to differ materially from those in the forward-looking statements: satisfaction of regulatory and other requirements; actions of regulatory bodies and other governmental authorities; additional clinical trial results; changes in laws and regulations; issues with product quality, manufacturing or supply, or patient safety issues; and other risks identified in Baxter's and Merrimack's most recent filings on Form 10-K and other SEC filings, all of which are available on their respective websites. Neither Baxter nor Merrimack undertakes to update their forward-looking statements.

1American Cancer Society. Cancer Facts and Figures 2014. Atlanta: American Cancer Society; 2014.
2World Health Organization. GLOBOCAN 2012: Estimated Cancer Incidence, Mortality and Prevalence Worldwide in 2012; Lyon, Fr.: International Agency for Research on Cancer; 2012.