With this move, AbbVie wants to accelerate its commercial and clinical presence in the solid tumor space.

"The acquisition of ImmunoGen demonstrates our commitment to deliver on our long-term growth strategy and enables AbbVie to further diversify our oncology pipeline across solid tumors and hematologic malignancies," said Richard A. Gonzalez, chairman and CEO of AbbVie.

ImmunoGen's Elahere is the first targeted medicine to show meaningful survival benefit in PROC. As a fast-growing solid tumor therapy, Elahere provides AbbVie with a potential multi-billion-dollar on-market medicine with expansion opportunities in earlier lines of therapy and larger segments of the ovarian cancer market, the company said.

Mark Enyedy, president and CEO of ImmunoGen, commented: "With global commercial infrastructure and deep clinical and regulatory expertise, AbbVie is the right company to accelerate geographic and label expansion, and realize the full potential of Elahere as the first and only ADC approved in ovarian cancer."

AbbVie will acquire all outstanding ImmunoGen common stock for $31.26 per share in cash. The proposed transaction is subject to customary closing conditions, including receipt of regulatory approvals and approval by ImmunoGen stockholders.