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 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.

After a research note raised potential safety concerns with Amgen's lead obesity candidate, the company defended its drug and has asked the journal to issue a correction and add in the finalized data.

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’s stock fell 7% after an analyst posted a note on MariTide’s influence on bone density which was noticed in a data spreadsheet.