BioCentury
ARTICLE | Product R&D

A question of color

Amgen, Lilly overturn the brown fat theory of FGF21 but differ on interpretation

May 28, 2015 7:00 AM UTC

The metabolic benefits of FGF21 that prompted at least five companies to pursue it for weight loss were thought to lie in the hormone's ability to cause browning of white fat. But two independent studies from Amgen Inc. and Eli Lilly and Co. have countered that theory by showing FGF21-based compounds can induce weight loss and antidiabetic effects without affecting UCP1 - a key feature of white-to-brown conversion. However, the companies differ on the conclusions they're drawing.

While Amgen isn't disclosing its plans, the company believes the data call for a new hypothesis to explain the activity of FGF21. ...