Allakos (ALLK) shares were over 45% higher in recent premarket trading Wednesday after the company said it has entered into a definitive agreement to be acquired by Concentra Biosciences.

Under the merger agreement, a Concentra subsidiary will start a tender offer to acquire all outstanding shares of Allakos for $0.33 per share in cash by April 15.

The transaction is expected to close in May, Allakos said.