Pfizer has filed two lawsuits against the metabolic-focused startup Metsera and Novo Nordisk as of Tuesday. The first suit, filed last Friday, claims that Novo Nordisk’s rival bid for Metsera is a move “to suppress competition,” Pfizer said in a press release.
Metsera could be a vital acquisition for either company. The company is developing a once-monthly injectable GLP-1RA which had strong Phase 2b results and a potential oral GLP-1 pill. For Novo, this deal would strengthen their pipeline and help them compete against rival Eli Lilly. For Pfizer, this could be an opportunity to reenter the obesity market after an oral weight-loss candidate failed earlier this year.
Lawsuits timeline (2025)
Sept. 22
Press release
Pfizer announces acquisition of Metsera for an upfront value and a contingent value right of up to $7.3 billion.
Sept. – Oct.
BioSpace Report
Metsera’s regulatory filings later disclose that Novo Nordisk had submitted bids during this time that were rejected due to “regulatory risks”.
Oct. 30
The Guardian
Novo Nordisk submits its first public bid valuing Metsera up to $9.0 billion. Metsera deems it a “superior” proposal and gives Pfizer four days to negotiate or match the bid.
Oct. 31
Press release
Pfizer files its first lawsuit against Metsera and Novo Nordisk, claiming breach of contract. The company claims that Novo’s offer is “illusory” and has high antitrust risks. Pfizer requests a Temporary Restraining Order to block Metsera from terminating their agreement.
Nov. 3
Nasdaq Report
Pfizer files a second lawsuit claiming that Novo’s bid violates the Clayton Antitrust act and the Sherman Act. It claims Novo’s bid is an attempt to suppress a competitor.
AP News
Pfizer submits a counter bid increasing their bid from $7.3 billion to $8.1 billion.
Nov. 4
Investing.com
Novo Nordisk increases its offer to $10 billion in response. Metsera deems its new bid is still superior and gives Pfizer two days to respond.
Economic Times
At a preliminary hearing a judge indicates she is reluctant to involve the court in the bidding war.
Nov. 5
Economic Times
Based on the court hearing, Pfizer’s final deadline to match or exceed Novo’s $10 billion bid is set for EOD Nov. 5.
Reuters
Pfizer matches Novo’s $10 billion bid, two people familiar with the process told Reuters.
Nov. 6
Reuters
Novo again raises its bid. The exact amount is undisclosed
As of Nov. 7 2025
The first suit: breach of duties
In late September, Pfizer announced an agreement to acquire Metsera for $4.9 billion upfront with a contingent value right (CVR) bringing the potential total to $7.27 billion. Novo Nordisk also submitted a bid, but Metsera deemed it carried “regulatory risks.”
However, Novo continued to submit unsolicited offers, raising its bid. Metsera then deemed an offer of $10 billion from Novo “superior” to Pfizer’s $8.1 billion agreement.
Metsera then gave Pfizer four days to negotiate. Pfizer shot down the deadline, insisting that Novo Nordisk’s proposal was not superior. Pfizer has claimed that Metsera has breached its fiduciary duties by considering the Novo offer.
Pfizer requests that the court issue a temporary restraining order to block Metsera from terminating the merger until Pfizer is “heard on this important matter,” the company said in the press release. It claims that “Metsera’s and its Directors’ actions, as well as those of Novo Nordisk, are in clear violation of their respective contractual and legal obligations.”
The second suit: anticompetitive action
On Monday, Pfizer filed a second lawsuit against Novo and Metsera claiming Novo’s bid to acquire Metsera constitutes “an anticompetitive action,” according to a press release. Pfizer claims that Novo is attempting to kill a competitor before it gains Pfizer’s support. The company argues that Novo’s proposed agreement would be “to the detriment of millions of Americans,” who suffer from diabetes or obesity.
The suit also names Metsera’s lead shareholders: Validae Health, L.P., Population Health Partners GP, LLC, ARCH Venture Fund XII, L.P. and ARCH Venture Fund XIII, L.P. which Pfizer claims “conspired with Metsera and Novo Nordisk in furtherance of these anticompetitive activities.”
Pfizer claims the defendants are in violation of the Clayton Act, an act aimed at preventing anticompetitive practices and the Sherman Act, which outlaws monopolistic business practices.
Metsera issued a statement saying, “Pfizer is trying to litigate its way to buying Metsera for a lower price than Novo Nordisk. Metsera’s Board of Directors will continue to stand firm on behalf of shareholders and patients. Pfizer’s litigation arguments are nonsense, and Metsera will address them in court.” Novo Nordisk has not released any statements about the litigation.
A preliminary evaluation by a Delaware judge stated that there is no need to involve the court in the bidding war. Another hearing is scheduled for Wednesday.
Filed Under: Endocrinology, Metabolic disease/endicrinology
