Amgen’s MariTide Shows 20% Weight Reduction, Leaving Bulls Disheartened

The anticipated weight loss results for Amgen’s MariTide have been released, revealing that the antibody peptide conjugate achieved an average weight reduction of up to 20% at the conclusion of week 52 for individuals who are obese or overweight.
However, the Phase II findings left some doubts regarding efficacy when comparing it to placebo, as this critical measure was not disclosed by Amgen. BMO Capital Markets noted that investors were particularly eager to see this endpoint reflected in the data release. Jefferies analysts remarked that while the results are acceptable, they do not fulfill the most optimistic expectations.
While investors had hoped for a weight loss percentage between 20% and 25%, the results emerged towards the lower end of that spectrum. Nonetheless, Jefferies pointed out that there was no indication of a plateau as the trial progressed, suggesting that additional weight loss might be possible beyond this initial evaluation phase.
As a result, Jefferies observed that while optimistic investors may feel let down, skeptics might view Amgen’s position as less concerning now.
Following the announcement, Amgen’s stock experienced a notable decline of over 11%, settling at 0.75 per share at Tuesday’s market open. BMO had anticipated this fall, attributing it to investor reactions to the perceived lack of efficacy when adjusting for placebo and potential negative implications from a comprehensive readout.
Comparison of MariTide with GLP-1s for Weight Management
Currently, the data concerning MariTide resemble the outcomes achieved by Eli Lilly’s Zepbound (tirzepatide) during its highest dosage trials in a comparable patient demographic, according to analysts from Leerink Partners. Their findings also indicate significant and meaningful improvements in various cardiometabolic metrics, such as blood pressure and triglycerides.
BMO affirmed that the data are indeed robust.
Regarding safety, Amgen reported no noted relationship between MariTide and changes in bone mineral density—this finding arises in direct response to a recent claim suggesting heightened fracture risks associated with the drug. Gastrointestinal issues, including nausea, vomiting, and constipation, were the most prevalent adverse effects. These symptoms are commonly associated with GLP-1 therapies. Amgen clarified that these effects were mild, short-lived, and typically occurred with the initial dosage, with instances of nausea and vomiting decreasing with dosage escalation.
The trial saw an 11% discontinuation rate due to adverse events, while gastrointestinal-related discontinuations were below 8%. BMO posited that the tolerability profile appears more favorable than initially expected, while Jefferies deemed it merely acceptable, noting it had a slightly higher rate in several areas.
Jay Bradner, Amgen’s executive vice president of R&D and chief scientific officer, expressed optimism about the results bolstering plans for the Phase III MARITIME study aimed at individuals with obesity and related illnesses. Additionally, the second phase of the Phase II trial will persist in assessing weight loss past the 52-week mark, alongside durability and weight maintenance following the cessation of MariTide.
BMO called the overall findings encouraging for prospective development, especially considering the prospect of monthly dosing compared to the weekly regimens of GLP-1s. Executives highlighted the potential advantages of less frequent dosing compared to existing weight loss drugs during a conference call on Tuesday morning, suggesting that this factor could position Amgen favorably in the market. The ongoing research is exploring both monthly and bi-monthly dosing, with plans to include quarterly administration in future assessments.
“Overall, the profile appears generally similar to tirzepatide’s, but with a monthly dosing schedule that could potentially allow for even less frequent treatment options,” Jefferies remarked.