Concentra’s Surprise Bid Disrupts Acelyrin-Alumis Merger Plans

Concentra Biosciences made an unsolicited offer to acquire Acelyrin for $3.00 per share in cash, plus contingent value rights related to future proceeds from development programs9 4.

This offer comes after Acelyrin had already announced a merger agreement with Alumis Inc. on February 6, 20259 6.

The Acelyrin-Alumis merger was planned as an all-stock transaction, with Alumis and Acelyrin stockholders owning approximately 55% and 45% of the combined company, respectively6.

The original Acelyrin-Alumis merger was expected to close in the second quarter of 2025, subject to stockholder approval and other customary closing conditions9 6.

Acelyrin's Board of Directors is now evaluating Concentra's offer while remaining committed to its fiduciary duties and obligations under the merger agreement with Alumis9.

Acelyrin's lead program is lonigutamab, a subcutaneously delivered monoclonal antibody targeting IGF-1R for the treatment of thyroid eye disease9.

The unexpected offer from Concentra has introduced uncertainty into the previously announced merger plans, potentially altering the landscape of this biopharmaceutical industry deal7 2.