After GLP-1: Why Every Big Drugmaker Is Now Chasing Amylin

For about three years the obesity drug story has been a GLP-1 story. Semaglutide and tirzepatide proved the category, and everything since has been a variation on the theme.

That is changing. The most interesting results of 2026 are coming from a second hormone called amylin, and effectively every major drugmaker now has a candidate in the running. If you want to know what the obesity market looks like in 2028, this is the pipeline to watch.

What amylin actually is

Amylin is a hormone your pancreas releases at the same time as insulin, every time you eat. It is one of the body's fullness signals. It slows how quickly your stomach empties and tells your brain that food has arrived.

The important part is that this is a separate system from GLP-1. Both make you feel full, but they do it by different routes. That means you can run both at once and get more effect than either alone, which is the entire strategic idea behind the current wave.

Natural amylin is useless as a medicine because it breaks down within minutes. Every drug below is an engineered version built to last long enough to inject once a week, or in one case once a month.

Who is in the race

Novo Nordisk is furthest along. Its amylin drug cagrilintide produced about 11.8 percent average weight loss on its own in late stage testing. Paired with semaglutide in a single weekly injection called CagriSema, that rose to 22.7 percent at 68 weeks. Novo filed with the FDA in December 2025 and a decision is expected late this year.

Eli Lilly has posted the most eye-catching number. Its candidate eloralintide, at a 9 mg weekly dose, showed a 20 percent average reduction in body weight at 48 weeks against 0.4 percent for placebo. That is mid stage data, but it is a striking result for an amylin drug used on its own.

Roche and Zealand Pharma are developing petrelintide, which delivered up to 10.7 percent average weight loss at week 42 against 1.7 percent for placebo in its ZUPREME-1 trial. The partners plan to start late stage studies in the second half of 2026, with results from a second mid stage trial in people with type 2 diabetes due around the same time.

Amgen is taking a different angle with MariTide, which pairs a GLP-1 agonist with a GIP blocker. Mid stage data showed up to 20 percent weight loss at 52 weeks, and notably the weight was still coming off rather than leveling out. Its real differentiator is dosing: once a month rather than once a week.

Why monthly dosing matters more than it sounds

It is easy to skim past the dosing schedule, but it may end up mattering as much as the weight loss numbers.

The quiet problem with GLP-1 drugs is that a large share of people stop taking them within a year. Weekly injections are a real commitment, and every week is another chance to give up. Cutting that to twelve injections a year instead of fifty two is a meaningful change in how hard the treatment is to stick with.

Pfizer is chasing the same idea from the GLP-1 side with its monthly candidate, which we covered when the VESPER-3 results landed. The fact that two different companies are pushing toward monthly dosing at the same time tells you where the competition is heading once the weight loss numbers stop separating the field.

Read the numbers carefully

Here is the part the headlines skip. Almost everything above is mid stage data, and comparing results across different trials is unreliable.

Different studies enroll different people, run for different lengths of time, and use different definitions of who counts in the final analysis. A 20 percent result in one trial and a 22 percent result in another do not mean the second drug is better. The only comparison that really counts is a head to head trial, where both drugs are given to similar people at the same time.

We already have one useful example of why this matters. When CagriSema was tested directly against tirzepatide, it produced 23.0 percent weight loss against 25.5 percent. The combination that had looked dominant in isolation did not win when measured side by side.

Mid stage results also have a long history of shrinking in late stage trials, where the participant groups are larger and more varied. Some of these numbers will come down.

What to take from this

The genuinely interesting finding is not any single drug. It is that stacking two separate appetite pathways reliably beats using one. That principle now has enough supporting data across enough companies that it is unlikely to be a fluke, and it is why the leading candidates by weight loss, including retatrutide and CagriSema, all hit more than one receptor.

For anyone actually choosing a treatment today, none of this is available yet. The practical takeaway is simply that the options in two years will probably be more effective and less frequent than the options now, which is worth knowing before committing to anything long term. For a wider view of what else is moving through the pipeline, our roundup from the ADA 2026 meeting covers the rest of the field.

Sources: PharmaVoice on the amylin wave and Roche Phase II results for petrelintide.