SAN DIEGO and OSAKA, Japan — Orexigen Therapeutics Inc. and Takeda Pharmaceutical Co. Ltd. have entered into an exclusive partnership to develop and commercialize Contrave, Orexigen’s investigational drug for the treatment of obesity, in the United States, Canada and Mexico.

The companies said Thursday that Orexigen submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration for Contrave on March 31, 2010, and the Prescription Drug User Fee Act (PDUFA) action date has been set for Jan. 31, 2011.

Contrave (naltrexone SR/bupropion SR) is a combination therapy believed to address biological and behavioral drivers of obesity, according to Orexigen and Takeda. The central pathways targeted by the treatment are involved in controlling the balance of food intake and metabolism, as well as regulating reward-based eating behavior.

Under the agreement, Orexigen will receive an upfront cash payment of $50 million from Takeda, and Takeda will obtain an exclusive marketing right from Orexigen in the United States, Mexico and Canada while Orexigen retains the right to co-promote with Takeda in the United States. Orexigen will be eligible to receive payments of over $1 billion upon achieving certain regulatory and sales-based milestones. Assuming Contrave is commercialized, Takeda will pay tiered double-digit royalty payments on net sales in the territory.

"Takeda is an ideal partner for Contrave given its proven track record in commercializing innovative medicines and its commitment to the treatment of obesity," stated Michael Narachi, president and chief executive of Orexigen. "We believe this is a great strategic partnership to enable our goal of a strong market entry for Contrave, if approved. It has been our belief that getting a partner involved early would be critical to a high-quality launch of Contrave, and with this partnership now in place, we are tightly focused on the regulatory review process and securing approval for Contrave."

Plans call for Orexigen and Takeda to work together on ongoing development of the product, with Orexigen leading preapproval activities and Takeda leading post-approval activities. The companies said they will share in the costs of any future development of the product.

"Contrave represents an important addition to Takeda’s cardiovascular and metabolic disease franchise, and we look forward to partnering with Orexigen," commented Shinji Honda, president and CEO of Takeda Pharmaceuticals North America Inc. "Takeda has deep experience in providing important medicines to treat chronic disease, and Contrave will help us provide a full spectrum of treatment to patients for the management of obesity."

According to the two companies, about 75 million Americans suffer from obesity, and that number is expected to rise to 103 million by 2018. Obesity is a chronic condition linked to such health consequences as type 2 diabetes, cardiovascular disease, cancer and depression. And despite rising public health concerns about obesity, two-thirds of the U.S. adult population is overweight or obese, the companies noted.