Metsera’s once-monthly Amylin drug shows strong weight loss results

USA – Metsera is making waves in the weight-loss drug market after unveiling encouraging results from early trials of its once-monthly amylin analogue, MET-233i.

The biotech company’s shares surged over 10% on Monday following the announcement, signaling strong investor interest in its potential to compete with established weekly GLP-1 treatments such as Novo Nordisk’s Wegovy and Eli Lilly’s Zepbound.

Metsera’s Phase I trial enrolled 80 overweight or obese participants without type 2 diabetes, testing both single and multiple doses of MET-233i over five weeks. Key findings include:

• Patients receiving the 2.4 mg single dose lost an average of 5.3% body weight by day 8, maintaining significant reductions over four weeks.
• In the multiple-dose arm, those on the highest 1.2 mg dose lost an average 8.4% of body weight by day 36, with some individuals seeing reductions as high as 10.2%.

Long-lasting effect and minimal side effects

MET-233i boasts a half-life of 19 days, making it the most durable amylin analogue available, according to Metsera.

This extended effect supports once-monthly dosing, which may simplify weight-loss treatments compared to weekly injections.

Dr. Steve Marso, Metsera’s Chief Medical Officer, emphasized that trial participants experienced weight loss comparable to leading GLP-1 drugs while maintaining mild, short-lived gastrointestinal side effects, primarily in the first week of dosing. No serious adverse events were reported.

Competition in the market

Metsera is developing MET-233i both as a standalone weight-loss treatment and in combination with MET-097i, its ultralong-acting GLP-1 agonist, which has previously demonstrated up to 11.3% weight loss in trials.

Meanwhile, industry competitors face challenges:

• Novo Nordisk’s CagriSema, a combination of amylin analogue cagrilintide and Wegovy, has underperformed in Phase III trials, contributing to a leadership shake-up at the company.
• Zealand Pharma recently secured a US$ 1.5-billion deal with Roche for its long-acting amylin candidate, petrelintide, after showing 8.6% weight loss at 16 weeks in early trials.

Future outlook

Metsera is pushing forward with a monotherapy trial featuring 12 weekly doses, followed by a monthly dose at week 13, with results expected in late 2025.

Additionally, the company is testing MET-233i alongside MET-097i in a 12-week co-administration study, with findings due by early 2026.