Sage Therapeutics has rejected the unsolicited acquisition offer it received earlier this month from longtime partner Biogen Inc.

Sage Therapeutics (NASDAQ:SAGE) is reportedly suing Biogen (NASDAQ:BIIB) over enforcement of a standstill agreement in the wake of an unsolicited takeover bid valued at around $469M. The full lawsuit,

Cambridge, USA-based biotech Sage Therapeutics yesterday announced that, while rejecting an unsolicited takeover offer, its board of directors has initiated a process to explore strategic alternatives for the company.

Sage Therapeutics announced its boards unanimous rejection of Biogens $469 million acquisition offer, stating the proposal significantly undervalues the company and does not align with shareholder interests.

Sage Therapeutics said on Monday that its board has unanimously rejected Biogen’s $469 million offer, stating it "significantly undervalues" the company and does not serve shareholders' best interests.