Novo Nordisk A/S’s best-sellers Ozempic and Wegovy transformed the firm into a global pharmaceutical giant. But four years after Wegovy’s US launch, the Danish drugmaker’s growth is slowing. About one million patients in the US are taking cheaper copycat options.

Shares in Novo Nordisk fell as much as 6% on Friday before recovering some ground later in the session, extending recent losses that threaten to wipe out all the gains since the drugmaker launched its blockbuster weight-loss treatment Wegovy four years ago.

Novo Nordisk appoints Maziar Mike Doustdar as the new CEO to tackle falling sales and shares amid stiff competition in the weight-loss drug industry, specifically from Eli Lilly's Zepbound. The change in leadership comes after the removal of former CEO Lars Fruergaard Jorgensen and growing concerns about the company's U.