Key Takeaways Amgen refutes in a press release that its trial obesity drug, MariTide, may cause bone loss density. Amgen's stock has risen 4.6% this year against a decrease of 3.8% for the pharmaceuticals industry.

Amgen has rebuffed claims made by an analyst suggesting that its obesity drug MariTide is associated with reductions in bone mineral density that could undermine its ability to compete in the fast-growing sector.

Amgen said on Wednesday there was no link between its experimental weight-loss drug and changes in bone density, a day after those concerns wiped off more than $12 billion from the company's market value.