10:44 AM EST, 11/04/2025 (MT Newswires) -- (Updates with additional details starting in second paragraph.)

Metsera ( MTSR ) said Tuesday its board received a "superior" amended acquisition proposal from Novo Nordisk ( NVO ) , challenging its existing merger agreement with Pfizer ( PFE ) .

Novo Nordisk ( NVO ) would pay Metsera ( MTSR ) $62.20 per common share in cash, up from $56.50, along with certain amounts for employee equity and transaction expenses. In exchange, Metsera ( MTSR ) would issue non-voting preferred stock to Novo Nordisk ( NVO ) representing 50% of its share capital. Metsera ( MTSR ) would then declare a cash dividend of $62.20 per common share to its shareholders, with payment following a record date set 10 days after signing definitive agreements.

In the second step, contingent on shareholder and regulatory approvals, Metsera ( MTSR ) shareholders would receive a contingent value right worth up to $24 per share in cash, based on development and regulatory milestones. Novo Nordisk ( NVO ) would then acquire the remaining outstanding shares.

The revised proposal values Metsera ( MTSR ) at up to $10 billion, or $86.20 per share, representing a 159% premium to Metsera's ( MTSR ) closing price as of Sept. 19, the last trading day before the Pfizer ( PFE ) deal was announced, Metsera ( MTSR ) said.

Pfizer ( PFE ) on Monday revised its own offer to $60 per share in cash, up from $47.50, while reducing the contingent value right to up to $10 per share in cash, down from $22.50, Metsera ( MTSR ) said.

Metsera ( MTSR ) said it notified Pfizer ( PFE ) that it had deemed Novo Nordisk's ( NVO ) amended proposal as a "Superior Company Proposal," triggering a two-day window for Pfizer ( PFE ) to negotiate revised terms.

Pfizer ( PFE ) did not immediately reply to a request for comment.

Metsera ( MTSR ) shares rose 15% in recent Tuesday trading, Novo Nordisk ( NVO ) gained 0.8%, and Pfizer ( PFE ) gained 0.8%.

Price: 69.88, Change: +9.15, Percent Change: +15.07