Amgen drops obesity drug after phase 1 results, focuses on MariTide

Amgen has decided to discontinue its development of AMG 786, an obesity treatment candidate, to focus its resources on a more promising contender, MariTide. This strategic shift was announced during the company's first-quarter earnings call, where Jay Bradner, M.D., Amgen’s executive vice president of research and development and chief scientific officer, explained that AMG 786 did not meet the company's expectations. The phase 1 clinical trial for AMG 786, which assessed its safety and tolerability, particularly among healthy participants and those with obesity, is now complete.

Bradner highlighted that MariTide, formerly known as AMG 133, has shown a differentiated profile that raises the standard for Amgen's obesity treatments. This new focus includes investing in MariTide and several preclinical assets. MariTide is currently undergoing a phase 2 dose-ranging study that involves overweight or obese participants, with or without Type 2 diabetes. Amgen's leadership, including CEO Bob Bradway, has expressed confidence in MariTide's potential to address significant unmet medical needs following an interim analysis of the study.

Despite the optimism, Amgen remains cautious about releasing detailed information on MariTide. During the earnings call, specific questions about the ongoing study were largely unanswered to avoid introducing bias or affecting the study's blinding. However, Bradner did reveal that top-line results from the 11-arm phase 2 study are expected by late 2024.

MariTide is a GIPR antagonist conjugated to two GLP-1 analogues. It functions by modulating appetite and insulin secretion, targeting receptors for the hormones GLP-1 and GIP. This mechanism is similar to Eli Lilly's obesity drug Zepbound, but differs in its approach to the GIP receptor. While Zepbound is a dual agonist for both GLP-1 and GIP receptors, MariTide acts as a monoclonal antibody linked to peptides that increase GLP-1 receptor activity while reducing GIP receptor activity.

Administration of MariTide is expected to be patient-friendly, likely involving a convenient handheld autoinjector device that could offer monthly, or even less frequent, single injection administrations. This could significantly enhance patient compliance and convenience compared to other treatment options.

Amgen is planning a comprehensive phase 3 program for MariTide, which will cover obesity, obesity-related conditions, and diabetes. Additionally, another phase 2 trial is set to launch, focusing on the drug's efficacy in patients with diabetes, with and without obesity.

Analysts from William Blair have expressed growing confidence in MariTide's potential, noting its ability to differentiate itself from other therapies in development. They believe that Amgen has the necessary capacity and expertise to maximize the development and commercial potential of MariTide, projecting it to achieve multi-blockbuster status despite facing significant competition in the field.

This strategic pivot to prioritize MariTide underscores Amgen's commitment to innovation in the obesity and diabetes treatment landscape. The company's robust pipeline and focused investment in promising assets like MariTide reflect its strategy to address critical health issues with novel therapeutic options.