"ImmunoGen played a key role in the generation and early development of Kadcyla, the first ADC approved for the treatment of HER2-positive breast cancer, and we are pleased to see the continued progress of this important therapy in the market," said Mark Enyedy, President and Chief Executive Officer. "As ImmunoGen evolves into a fully-integrated company with our proprietary portfolio, this transaction further strengthens our balance sheet as we execute on our strategic priorities and work to deliver more good days to people living with cancer."

This transaction entails the sale of the residual interest held by ImmunoGen from a prior transaction with Immunity Royalty Holdings, L.P. (IRH). In 2015, ImmunoGen announced a $200 million non-dilutive royalty transaction through which ImmunoGen sold the right to receive 100% of the royalty revenue on Kadcyla commercial sales to an undisclosed threshold amount, subject to certain conditions. Once the applicable threshold was met, ImmunoGen would receive 85% of the Kadcyla royalty revenue and the original purchaser would receive 15% for the remaining term of the royalty. With this transaction, OMERS now owns 100% of ImmunoGen's rights to receive Kadcyla royalties.

MTS Health Partners, L.P. acted as exclusive financial advisor to ImmunoGen and Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. acted as special transactional counsel to ImmunoGen.