Key Points
- Amgen shares plunged as analysts weighed bone density loss data from an early-stage trial of its experimental weight-loss injection, MariTide.
- While some analysts called the additional data a potential safety risk, others said the stock move was an overreaction and more data on a larger patient group was needed.
- The drug is a promising potential competitor in the market for weight-loss drugs designed to be taken monthly, rather than once a week like existing injections from Novo Nordisk and Eli Lilly.
Another suggested the possibility of new safety risks, arguing that the market reaction was too early and that further information from a broader patient group was needed.
The drug is a promising potential competitor in the weight-loss drug market. It is designed to be taken monthly, rather than weekly like existing injections from Novo Nordisk and Eli Lilly, and promotes weight loss in a different way.
Wall Street is eagerly awaiting MariTide, which is scheduled to be announced before the end of this year.
On Tuesday, analysts pointed to additional publicly available data from the phase one study, which showed that the highest dose of MariTide, 420 milligrams, was associated with bone mineral density declines over 12 weeks. This decline means bones lose calcium and other minerals, making them more fragile and more prone to fractures.
In a research note, Cantor Fitzgerald analyst Olivia Brayer called the data “an unknown” and suggested it could be a potential risk associated with drugs like MariTide, which work by using what’s called GIPR antagonism. Amgen’s shot works by blocking a gut hormone receptor called GIP but also activates another appetite-suppressing hormone called GLP-1.
That’s unlike Eli Lilly’s obesity drug, Zepbound, which activates both GIP and GLP-1. Wegovy activates GLP-1 but doesn’t target GIP, which can also affect how the body breaks down sugar and fat.
“On the one hand, patients may naturally lose bone mineral density during weight loss treatment,” Brayer wrote.
But Brayer said, “on the other hand, this may not be the beginning because there seems to be a dose-dependent increase” in bone mineral density loss. That is, patients appear to lose more bone mineral density the higher the dose they take.
Meanwhile, Jefferies analyst Michael Yee said in a note that the additional MariTide data did not appear to be cause for concern. Yee acknowledged that patients taking the highest dose of the drug experienced decreased bone density, but said the data was “unclear” and did not provide any definitive conclusions.
For example, he points to data on lower doses of the drug that showed bone density actually increased by 1% before returning to normal. Yee adds that “changes” in bone mineral density are a known side effect of weight-loss drugs in the first one to three months of use because people lose significant weight quickly.
Amgen is also aware of “hypothetical concerns” about bone mineral density loss, Yee said, citing the company’s discussions with management.
Jefferies specified that while it is not specified that there are no results in any way, they believe there are no issues concerning significant and sustained bone mineral thickness decline in time, or professional dangers or concerns. Overall, they doubt if there are any issues and anticipate that the results will certainly return to normal gradually.
BMO analyst Evan Seigerman wrote in a note Tuesday that “We would be cautious about making a blanket judgment on MariTide’s safety profile with this data.”
He added that “we would be more comfortable assessing the safety profile in a larger patient cohort.” There may not be a clear answer until Amgen releases full phase two trial data on the drug.
Seigerman wrote that their view on MariTide remains the same and they believe it is oversold if there is any upside.
