Pfizer sues Novo Nordisk again over Metsera obesity drug bidding war

Pfizer filed a second lawsuit against Novo Nordisk on Monday, accusing the Danish drugmaker of structuring its roughly $9 billion bid for Metsera to stall the biotech's obesity treatments rather than to close a deal ^[1]. Novo and Metsera rejected the claims the same day, and a judge is set to review the complaints on Tuesday ^[1].

The antitrust suit, filed in U.S. District Court in Delaware, alleges Novo is using a 30-month "outside date" in its bid — the period before either side can walk away — to delay Metsera's entry into the market for obesity drugs that target the GLP-1 protein, which Novo and Eli Lilly currently dominate ^[1]. Pfizer says its own deal with Metsera carried a nine-month timeline and received early termination of antitrust review on October 31 ^[1].

Pfizer agreed to pay up to $7.3 billion for Metsera in September, after a private bidding war with Novo that ran for months ^[1]. Metsera rejected Novo's offer six times, saying Novo already held a large share of the market and could face antitrust scrutiny ^[1]. Last week, after Novo's top investor overhauled the board, Novo launched a new unsolicited bid ^[1]. Metsera then called Novo's offer superior and gave Pfizer until Tuesday to submit a higher one ^[1].

That sequence led Pfizer to sue Metsera's board and Novo in Delaware's Court of Chancery on Friday, followed by the federal antitrust suit on Monday ^[1]. The state case was assigned to Vice Chancellor Morgan Zurn, who scheduled a hearing for Tuesday morning ^[1].

Metsera called Pfizer's allegations "nonsense" and accused the company of gaming the schedule by not suing sooner, when it knew of Novo's bid on October 25, and of trying to drive down its takeover price ^[1]. Novo said it closely adhered to all restrictions under the Pfizer merger agreement. "We are confident that the facts and the law are on our side," the company said, adding that Pfizer's suggestion Novo would impair or potentially stop an emerging US competitor is "absurd and not based on facts, common sense, or market realities" ^[1].

Pfizer also claims Novo offered Metsera shareholders $6.5 billion upfront, before regulatory review, and tied the company to restrictive covenants that delay or prevent clinical progress ^[1]. In the complaint, Pfizer wrote: "Something is clearly rotten in the state of Denmark" ^[1]. Novo said it would use its expertise "to accelerate the successful commercialisation of these assets to the benefit of patients in the U.S. and beyond" ^[1].

Metsera is developing an obesity drug that would be given by monthly injection, compared with the weekly injections required for Novo's Wegovy and Lilly's Zepbound and Mounjaro ^[1]. Analysts say Metsera's experimental therapies could generate $5 billion in sales, and some analysts forecast the obesity market could soon reach $150 billion annually ^[1].

Metsera shares fell 3.7% on Monday to close at $60.73. Pfizer shares ended flat, and Novo shares fell less than 1% ^[1].

Why it matters for patients

Metsera's obesity drugs are experimental and are not approved for use ^[1]. Nothing in the dispute changes what is currently available, and no clinical trial results, approval dates, prices or insurance coverage for Metsera's candidates have been disclosed in connection with the lawsuits ^[1].

The court fight is largely about timing. Pfizer argues a 30-month closing window would hold Metsera's drugs back; Novo disputes that and says it would speed their development ^[1]. How long that takes has not been reported. The outcome could shape how many companies are racing to sell monthly GLP-1 injections, a category where patients now have weekly options from Novo and Lilly ^[1].

What happens next

Vice Chancellor Morgan Zurn scheduled a hearing for Tuesday morning in Delaware's Court of Chancery ^[1]. The judge will analyze the complaints on Tuesday, the same day Metsera's deadline for a higher Pfizer bid falls ^[1]. No further court dates have been reported ^[1].