The news: Novo Nordisk entered the escalating acquisition battle for Metsera with a rival offer of up to $9 billion, topping Pfizer's earlier $7.3 billion bid.

Zooming in: Each of the three pharma companies released statements defending their position in what’s become a muddled merger situation.

• Metsera told Pfizer that it has four days to renegotiate terms, adding that it’s entitled to take Novo’s deal if it’s superior to Pfizer’s.
• Pfizer said Novo used its “dominant market position” in the weight loss drug space to “suppress competition,” while calling Novo’s bid “reckless.” Pfizer said it will pursue all legal avenues to enforce its rights under the previous agreement.
• Novo expressed confidence in its deal gaining approval, per WSJ.

Why it matters: The intense battle to acquire Metsera underscores how crucial a presence in the booming weight loss drug category has become for drugmakers.

• The obesity medication market could reach $150 billion at its peak in the next 10 years, an increase from the previous estimate of $105 billion, per a May 2025 analysis from Morgan Stanley.
• GLP-1 drugs are projected to generate over $72 billion in global sales this year—nearly double 2023’s total, according to TD Cowen estimates cited by WSJ. That’s expected to grow to $139 billion by 2030.
• The top four fastest-growing drugs in 2025 in terms of global YoY sales are all GLP-1 products from Novo and Eli Lilly, per estimates from Evaluate Pharma.

Acquiring Metsera would potentially be a significant boon for either Novo or Pfizer. Metsera has oral and injectable weight loss drug candidates in its pipeline, and recently released promising early clinical trial data. Metsera is developing a monthly weight loss shot, which would appeal to people who aren’t comfortable with the weekly injections currently offered by Novo and Lilly.

Novo is scrambling a bit after losing the weight loss drug market lead from Lilly despite bringing the first GLP-1 to market. And Pfizer has experienced multiple recent setbacks in developing an oral weight loss drug candidate.

What it means for pharma companies: The Metsera takeover clash signals how difficult and costly it will be for some companies to enter the weight loss drug category through M&A. Buying prices will surge amid cutthroat competition along with Novo and Lilly wanting to defend their market position. Developing novel obesity drugs that offer a significant advantage over current GLP-1s is challenging (see: Pfizer), but it could be the better option for some pharma firms that want to avoid potentially messy, drawn-out bidding wars.