Leaping for Leptin

More than a decade of unimpressive data had dampened enthusiasm for leptin as an obesity therapeutic when Amylin Pharmaceuticals Inc. acquired rights to the protein from Amgen Inc. in 2006. Three years and two trials later, Amylin has data on a combination therapy approach with a leptin analog that gives the company the chance to monetize its investment.

Under a deal announced last week, the biotech will receive $75 million up front from Takeda Pharmaceutical Co. Ltd. to co-develop and commercialize therapeutics for obesity, including a combination of Amylin's pramlintide and the metreleptin analog. Amylin is eligible for more than $1 billion in milestones, plus tiered double-digit royalties...