Amgen reports that its obesity drug led to up to 20% weight loss after one year, without any plateau.

• In a mid-stage trial, Amgen's experimental weight loss injection helped patients lose an average of up to 20% of their weight after a year.
• The company stated that it did not detect a plateau, suggesting there is still potential for weight loss beyond the 52-week mark.
• The data revealed how MariTide compares to blockbuster weight loss injections from Novo Nordisk and Eli Lilly, as well as the other treatments being developed by various drugmakers.

The company announced that its experimental weight loss injection helped patients with obesity lose up to 20% of their weight on average after a year in a critical mid-stage trial, as the company rushes to enter the booming obesity drug market.

The drug MariTide aided patients with obesity and Type 2 diabetes in losing up to 17% of their weight after a year. The company stated that they did not observe a plateau in either group of patients, indicating the possibility of continued weight loss beyond 52 weeks. MariTide was taken monthly or less frequently in the trial, which could provide an advantage over the weekly injections commonly used.

On Tuesday, Amgen's shares dropped approximately 7% in premarket trading. Prior to the data release, analysts predicted that MariTide should demonstrate a weight loss of at least 20% in the phase two trial, with some hoping for even greater results.

The trial results of Amgen's drug have been highly anticipated by Wall Street, as they will reveal how it compares to blockbuster weight loss injections from and and other treatments being developed by other drugmakers.

The first part of the year-long trial conducted by Amgen aimed to test various dose sizes, schedules, and regimens of MariTide. The trial's primary objective was to measure the amount of weight loss achieved, while also examining how long participants could go between injections while still losing weight.

While less than 8% of patients stopped treatment due to gastrointestinal side effects, approximately 11% discontinued treatment due to any adverse side effects.

Amgen Chief Scientific Officer Jay Bradner stated in an interview earlier this month that the company will use the results of the first part to refine the design of its late-stage study on the treatment, which is currently in the planning stage.

Amgen believes that MariTide may provide faster weight loss, better weight maintenance, and fewer shots compared to weekly injections like Wegovy and Zepbound. This could increase Amgen's chances of capturing a share of the weight loss drug market, which some analysts predict will be worth $150 billion annually by the early 2030s.

Wegovy resulted in a 15% weight loss over 68 weeks in late-stage studies, while Zepbound helped patients lose more than 22% of their weight over 72 weeks.

MariTide offers a unique solution for weight loss as it is a peptide antibody conjugate that activates receptors of GLP-1 and blocks receptors of GIP hormone.

Unlike Eli Lilly's obesity drug, Zepbound, which activates both GIP and GLP-1, Wegovy activates GLP-1 but does not target GIP, which may also affect how the body breaks down sugar and fat.

The mid-stage trial data for Amgen's MariTide has caused shares of the company to surge this year. However, a recent rally in the stock price lost momentum after one analyst raised concerns about the potential side effects of MariTide on bone density. Despite these concerns, Amgen has stated that it has no worries about the bone density data related to MariTide.

Trial design, data

The phase two trial included 592 patients, including 465 with obesity and 127 with both obesity and Type 2 diabetes. The trial tested MariTide in 11 different patient groups, with researchers examining various regimens and dosing levels, including 140, 280, and 420 milligrams.

Some patients were started on a lower dose of MariTide and gradually increased it over four weeks until they reached a higher target dose, while others had a slower dose escalation over 12 weeks.

One group of patients took MariTide every other month, while several other groups took it once a month. Bradner observed that Type 2 diabetes patients tend to have less favorable responses to weight loss medications, so Amgen did not include them in any groups that used dose escalation or less frequent dosing regimens.

Amgen is interested in examining the durability of MariTide's weight loss and how quickly people who lost weight rebound when they come off the medicine. The company invited patients to participate in the second part of the trial.

The second phase of the trial assesses any further weight loss after the first year on MariTide and examines less frequent drug dosing. Amgen has not disclosed when they will release data from the second phase of the trial.

Patients who continued the trial were randomly sorted into several groups.

In the second part of the trial, participants who took 140-milligram doses of MariTide will either continue with that dose or switch to a placebo for a year to assess the drug's long-term weight loss effects. Meanwhile, those who took 280-milligram doses in the first part of the trial will take lower doses of the drug for a year.

In the first part of the trial, some patients received 420-milligram doses and are now being tested on a quarterly schedule, which means they will receive a shot once every 12 weeks.