(Reuters) -Pfizer ( PFE ) and Novo Nordisk are locked in a bidding war for biotech firm Metsera ( MTSR ) as the pharmaceutical giants seek to augment their pipeline in the booming weight-loss drug market.

WHAT IS METSERA?

Metsera ( MTSR ) is a New York-based clinical-stage biotech firm focused on developing treatments for obesity and metabolic diseases.

Founded in 2022 by Population Health Partners and ARCH Venture Partners, the company went public on Nasdaq in January 2025 with an initial valuation of $2.7 billion. 

Since then, its market value has ballooned to about $7.5 billion as of Wednesday's close of trading.

Novo Nordisk has offered to buy the obesity drug developer for $10 billion, while Pfizer ( PFE ) has bid up to $8.1 billion.

WHAT OBESITY DRUGS IS METSERA DEVELOPING?

Metsera's ( MTSR ) lead pipeline asset is MET-097i, a GLP-1 receptor agonist designed for once-monthly injection. Novo's weight-loss drugs Wegovy and Eli Lilly's ( LLY ) Zepbound and Mounjaro require weekly injections.

The drug demonstrated placebo-adjusted weight loss of up to 14.1% after 28 weekly doses ranging from 0.4 mg to 1.2 mg in two mid-stage trials. A placebo-adjusted outcome is the difference in results between a treatment group and a control group that receives a placebo.

It plans to begin late-stage trials later this year and develop the drug for use in combination therapies and oral versions.

Metsera's ( MTSR ) second candidate, MET-233i, is currently in early-stage trials, where it helped patients lose 8.4% of their weight, when adjusted for placebo, at 36 days. The drug belongs to a class of medicines which mimic the pancreatic hormone amylin that is co-secreted with insulin. It is also an injectable drug.

The company is also developing MET-002o, an oral GLP-1 receptor agonist currently in early-stage trials. 

Leerink analysts estimate Metsera's ( MTSR ) drugs could surpass $5 billion in peak annual sales.

HOW DOES IT COMPARE TO MARKET LEADERS?

Eli Lilly's ( LLY ) Zepbound posted $3.6 billion in third-quarter sales, up 185% year-over-year, while its Mounjaro brought in $6.5 billion.

Sales of Novo Nordisk's Wegovy, a weekly semaglutide injection, have slowed due to competition and copycat products. A combination shot failed to meet expectations in late-stage trials, prompting a pivot to an oral version, which showed up to 16.6% weight loss in trials.

Pfizer ( PFE ) does not have an injectable weight-loss drug. The company discontinued two oral GLP-1 candidates, lotiglipron in 2023 and danuglipron in 2025 due to liver safety concerns, leaving it without a viable in-house obesity drug.

OWNERSHIP AND BACKERS

Arch Venture Partners is Metsera's ( MTSR ) largest shareholder, holding a roughly 25% stake through its ARCH Venture Fund XII and XIII, led by investor Bob Nelsen.

Alphabet Inc ( GOOG ) owns about 5% of the company. 

Metsera's ( MTSR ) executive chairman is Clive Meanwell, co-founder of Population Health Partners.