AstraZeneca seals obesity deal as Pfizer-Novo Nordisk battle for Metsera

After signing an $80 million investment deal with SixPeaks Bio last year, AstraZeneca has quietly exercised its option to acquire the obesity-focused Swiss biotech.

Its interest in the firm centres on SixPeaks’ bispecific antibody candidate that targets weight-management while aiming to preserve lean muscle mass – thus overcoming a common side effect of blockbuster glucagon-like peptide 1 (GLP-1) agonist treatments.

AstraZeneca’s third quarter figures show it made an initial payment of $170 million to gain the remaining shares in SixPeaks on 22 October and will pay a further $30 million after two years, with up to $100 million due if regulatory milestones are met.

SixPeaks’ lead candidate SPX-001, which has yet to enter clinical development, is a bispecific antibody that targets activin type IIA and B receptors.

It adds to an AstraZeneca obesity and weight management pipeline that already includes an oral GLP-1 candidate (AZD5004), a peptide treatment (AZD6234) and a GLP-1R glucagon dual agonist plus selective amylin agonist combination 9 (AZD9550 + AZD6234).

All of those candidates are currently in phase II clinical trials and the company’s recently increased US manufacturing investment will support its plans in obesity – a lucrative market defined to date by the runaway success of Novo Nordisk’s Wegovy (semaglutide) and Lilly’s Zepbound (tirzepatide).

Pfizer and Novo Nordisk battle to acquire Metsera

But while AstraZeneca’s relatively small deal to take control of SixPeaks appears to have been straightforward, Pfizer’s desire to snag a far bigger obesity prize is proving to be more complicated.

The company struck a $4.9 billion deal in September to buy US biopharma company Metsera and its portfolio of clinical-stage incretin and amylin research programmes, including a phase II weekly and monthly injectable GLP-1 drug.

Then last week Novo Nordisk swooped in with a rival, and unsolicited, bid of $6.5 billion, before this week raising its offer to one worth up to $10 billion – a proposal the company said had been “declared superior by Metsera’s board of directors”.

Pfizer responded strongly to Novo Nordisk’s “reckless and unprecedented proposal”, first suing Metsera, its directors and Novo Nordisk for breach of the original merger agreement and then filing federal antitrust claims against Metsera, its controlling stockholders and Novo Nordisk.

However, Pfizer’s request for a temporary restraining order to prevent Metsera from terminating their merger agreement in favour of a Novo Nordisk’s competing proposal was denied by the Delaware Chancery Court.

In a statement following that ruling Metsera said it was “gratified” by decision to deny Pfizer’s attempt to “block Metsera’s Board of Directors from acting in the best interests of shareholders”.

“Separately, Pfizer has reiterated it will continue to spuriously litigate. As we have previously noted, Pfizer’s litigation arguments are nonsense.”

For its part Pfizer said in a statement that it “intends to continue to pursue its claims vigorously through the ongoing litigation process as well as in its parallel antitrust litigation”.

“We are confident that Novo Nordisk’s unprecedented and illegal scheme to circumvent antitrust scrutiny will not stand.”

While the three companies’ increasingly fractious legal battle to determine the lucrative obesity drug market’s next major development rumbles on, the manufacturers behind its leading two drugs have struck a pricing deal in the US.

US agreement to lower Wegovy and Zepbound prices

The rapid pace of innovation in the obesity market has propelled ever increasing heights, with analysts at Goldman Sachs forecasting global non-US sales will reach $51.4 billion and US sales will hit $68.5 billion by 2033.

Looking to tackle costs in the US, amid a general push for lower prescription prices, President Donald Trump this week struck a ‘most favoured nation’ pricing deal with Novo Nordisk and Lilly to lower the cost of a number of their drugs, including those in obesity.

Novo Nordisk will cut the price of its semaglutide medicines, including the obesity drug Wegovy and diabetes treatment Ozempic, and will receive an expected three-year pharma tariff exemption.

The White House said Ozempic and Wegovy prices would fall from $1,000 and $1,350 per month, respectively, to $350 when purchased through its TrumpRx website.

If the company wins approval from the US Food and Drug Administration (FDA) for an oral version of Wegovy or any similar ‘GLP-1 pills’, those would initially be priced at $150 per month via TrumpRx.

Novo Nordisk will adopt the new pricing policy in 2026 and said it expected to see a “low single-digit impact” on global sales of the drugs next year. The White House said the company has also committed to an additional $10 billion investment in its “domestic footprint” and will produce “the Wegovy tablet, if approved, end-to-end in the US”.

Meanwhile, the price of Lilly’s Zepbound and its oral GLP-1 orforglipron will fall from $1,086 per month to an average of $346 when purchased through TrumpRx, according to the White House.