Japanese drug firm Eisai made a bet on obesity last week, signing a multi-million dollar deal with Arena Pharmaceuticals for the right to sell Arena's lorcaserin weight-loss pill, if approved. The deal includes a $50-million upfront, another $160 million based on development and approval milestones and a $1.16 billion, one-time payment that may follow based on annual sales. Eisai's timing was a bit surprising considering lorcaserin doesn't face an FDA panel until September and a decision until late October. Two other developers of diet pills are hoping for FDA approval, Orexigen for Contrave and Vivus for Qnexa, and both are seeking pharmaceutical partnerships. FDA is set to decide on Contrave in December. Qnexa faces an advisory panel July 15, and the FDA is scheduled to rule on the drug in October.