Pfizer’s (NYSE:PFE) entry into the obesity treatment market through its $4.9B deal to acquire Metsera (NASDAQ:MTSR) is the latest indication that Big Pharma wants a piece of the weight loss drugs pie that is currently dominated by Eli Lilly (LLY) and Novo Nordisk (NVO).
It is also a way for Pfizer to shore up its pipeline. Metsera has MET-097i, a weekly and monthly injectable GLP-1 receptor agonist, in phase 2, and MET-233i, a monthly amylin analog in phase 1.
While both candidates are still likely years from hitting the market, Pfizer is banking on a growing market for weight loss drugs. But the question is, given the strong positioning of Lilly’s Zepbound (tirzepatide) and Novo’s Wegovy (semaglutide), could the Metsera assets, assuming they are approved, compete in a crowded obesity drugs marketplace?
In a presentation accompanying a call on the deal, Pfizer said that MET-097i and MET-233i could differentiate themselves from other drugs through better tolerability. Also, a monthly version of either medication would provide a key convenience advantage for patients.
In a phase 1/2 MET-097i trial, relatively low rates of nausea, vomiting, and diarrhea were seen when the drug was administered with two titration steps (0.4/0.8/1.2 mg).
MET-097i data (with weekly dosing) showed that with titrated dosing, mean placebo-adjusted weight change from baseline at day 85 was -6.3%. With monthly dosing after 12 weeks of receiving the drug weekly, the figures at week 16 were -12.5% for 0.8 to 3.2 mg, and -14.1% for 1.2 to 4.8 mg.
For MET-233i, data from a phase 1 study showed the lowest rates of gastrointestinal aside effects were in the two lowest doses tested, though Pfizer noted that titration could improve tolerability.
As far as efficacy, the greatest weight loss seen — -8.4% — was seen with the 1.2 mg dose.
Pfizer also noted that both candidates could potentially be used in other indications, such as type 2 diabetes, chronic kidney disease, sleep apnea, and metabolic dysfunction–associated steatohepatitis (MASH).