Amgen stock dropped Monday after a "tough" American Diabetes Association discussion around its experimental weight-loss drug, MariTide.
Dr. Julio Rosenstock, the director of the Dallas Diabetes Research Center at Medical City, reviewed MariTide at the ADA meeting in Chicago. If approved, MariTide would be a monthly shot to reduce weight, rivaling weekly injections from Eli Lilly and Novo Nordisk.
But the meeting Monday was a stark reminder for Amgen "that it is NOT an incumbent in obesity," Evercore ISI analyst Umer Raffat said in a report.
Most of the Phase 2 test results were already known ahead of the ADA meeting. MariTide recipients lost up to 20% of their body weight, on average, over the course of a year. Vomiting and nausea rates were high without titrating — slowly increasing — the doses. But titrating helped tamp down on those side effects.
"But when we got to the discussant, it was a (very) tough outing for Amgen," Raffat said.
Amgen stock closed down 5.8% at 272.44, following the ADA discussion. Shares had climbed roughly 11% this year, as of Friday's close, but are trading below their 50-day and 200-day moving averages, according to MarketSurge. Shares have been consolidating with a buy point at 346.85 since last July.
Amgen Faces Off With ADA Discussant
Rosenstock noted some of the study's dosage groups included just four or five patients.
He also noted that this is a "tough horse race" with "too many molecules" in development, according to Raffat.
"If you look at the details, none of the points raised by him are so bad," Raffat said of Rosenstock's review. "But the body language through that review session was not good."
Still, Amgen is bullish on the future for MariTide. The drug works differently from others on the market or in development. Novo Nordisk's Wegovy mimics the GLP-1 hormone to improve feelings of satiety and blood sugar marks. Eli Lilly's Zepbound and Viking Therapeutics' experimental drug, VK2735, mimic GLP-1 and another hormone called GIPR.
MariTide, on the other hand, mimics GLP-1 and tamps down on GIPR.
Expanded Development Plans
Now, Amgen is expanding development plans for MariTide. It's planning to test the drug in patients with atherosclerotic cardiovascular disease, heart failure and sleep apnea. Meanwhile, a 72-week study of MariTide in weight management is "open and enrolling to intense demand," said Jay Bradner, executive vice president of research and development.
This speaks to the need for new treatment options for patients with obesity and related conditions, he told Investor's Business Daily.
"Only 2% of patients with obesity are currently served by the current medicines," Bradner said. "Just over half of patients who initiate obesity medicines today will stop taking them at one year. So, there's significant unmet need and we're seeing that in the demand to participate in the Phase 3 trial."
MariTide is roughly as effective as Zepbound. In clinical testing, patients who gave themselves weekly shots of the Eli Lilly drug lost up to 22.5% of their body weight. Bradner said patients who received MariTide shots didn't hit a weight-loss plateau. That means the weight loss could improve in the upcoming 72-week study.
In comparison, patients with type 2 diabetes lost about 17% of their body weight in Amgen's study. Bradner notes diabetics typically don't respond as well to GLP-1-based medicines.
Titrating To Reduce Side Effects
Less than a quarter of patients — 22.5% to 24.4% — experienced vomiting with the titrated dosing plans. Drugs that mimic the GLP-1 hormone tend to cause gastrointestinal side effects.
Without titrating, roughly 65% to 85% of patients reported vomiting, he said.
"Importantly, nobody dropped out of this trial," Bradner said. "The vast majority of symptoms were quite mild and well-tolerated by patients."
He said the dosage was titrated over the course of eight weeks. In comparison, other companies have used a six-month titration period, he said. Titrating also doesn't affect how well MariTide works. Even at the lowest 7-milligram dose — compared to the highest 420-milligram dose — patients lost 2.5% of their body weight within a week.
The Phase 3 study in weight management will also use a three-step dose escalation strategy, he said.
MariTide Still Has Years To Go
Amgen is still several years out from realizing the potential for MariTide.
The company started enrolling patients with obesity but not type 2 diabetes in the Phase 3 study this March. It doesn't expect to have the primary results until early 2027. That's the year analysts expect the first commercial sales of MariTide, at $26 million, according to FactSet. From there, sales could climb to $325 million and $300 million, respectively, over the next two years.
Bradner is bullish on the company's chances, though. What makes MariTide special is how long it can stay in the bloodstream. Eventually, he imagines some patients looking to maintain their weight loss could receive quarterly injections of MariTide.
"We need to find a way to keep patients on these effective medicines longer," he said. "And, so after initiation of weight loss with MariTide, we hope that we can produce data that directs patients and clinicians to a path that is convenient and simple to continue and maintain the hard-won weight loss that they've enjoyed."
Follow Allison Gatlin on X/Twitter at @AGatlin_IBD.
