Weight-Loss Drugmakers in ‘Whack-a-Mole’ Fight Against Knockoffs

The surging market for drugs treating diabetes and weight loss has spurred lawsuits from leading drugmakers and scrutiny from the FDA targeting vendors selling unauthorized versions of the blockbuster products.

Novo Nordisk’s Wegovy, Ozempic, and Rybelus have skyrocketed company sales this year as the prescription drugs have been demonstrated to treat more than one diagnosis. The same goes for Eli Lilly & Co.'s blockbuster Mounjaro. The drugs belong to a class of medicines known as GLP-1 antagonists used to treat type 2 diabetes and weight loss.

“Weight loss medication is the modern American Gold Rush,” said Robin Feldman, a law ...