By Maggie Fick, Jacob Gronholt-Pedersen and Stine Jacobsen

COPENHAGEN (Reuters) - Wegovy-maker Novo Nordisk ousted CEO Lars Fruergaard Jorgensen on Friday over concerns the company is losing its first-mover advantage in the highly competitive obesity drug market.

Under Jorgensen's leadership, Novo Nordisk became a world leader in the lucrative weight-loss drug market, with sky-rocketing sales of its Wegovy and Ozempic treatments.

However, Novo's shares have plunged since hitting a record-high in June last year as competition, particularly from U.S. rival Eli Lilly, makes inroads into its market share and as its pipeline of new drugs has failed to impress investors.

"The changes are made in light of the recent market challenges Novo Nordisk has been facing, and the development of the company's share price since mid-2024," Novo said in its statement.

Novo Nordisk Foundation, the non-profit which controls the company through its investment arm, instigated the early exit at a meeting in April, a spokesperson said.

Jorgensen told Reuters in an interview that he did not see the decision coming, and was only informed very recently.

Days earlier, Novo Nordisk cut its sales and profit forecast for the first time since the launch of Wegovy four years ago, though Jorgensen had predicted a return to growth in its biggest market in the second half of this year.

Still, analysts and investors were unconvinced of the need to replace him, with Novo's shares ending the day 1.8% lower.

"He was leading the company for eight years and was in my opinion extremely successful," Lukas Leu, a portfolio manager at Bellevue Asset Management, told Reuters.

Novo's chairman Helge Lund tried to reassure analysts and investors on a call that the company's strategy was intact and the plan for executing it had not changed.

"The way we know Novo Nordisk is that normally you have patience when you're on the right track, and then you let things move in the right direction once you have the strategy right," Danske Bank analyst Carsten Lonborg Madsen said on that call.

"It just feels like there's something that has gone pretty wrong here," he added.

The chairman told Reuters that discussions had taken place over the past few weeks. Jorgensen will remain in his role until a successor is found.

Eli Lilly, whose shares were up 2.6% on the news, has seen U.S. prescriptions for its Zepbound obesity shot surpass Wegovy since mid-March in its biggest market.

U.S. approvals for Zepbound and Wegovy were based on separate trials, but Lilly's drug helped patients lose more weight.