MORAb-202 is Eisai's first antibody drug conjugate and combines the company's in-house-developed antifolate receptor alpha antibody with its anticancer agent eribulin, using an enzyme-cleavable linker. The payload eribulin, known as Halaven, is the first in the halichondrin class of microtubule dynamics inhibitors with a novel mechanism of action.

The two companies will jointly develop and commercialize MORAb-202 in the following areas: Japan, China, countries in the Asia-Pacific region, the U.S., Canada, Europe (including the European Union and the U.K.), and Russia.

BMS will be responsible for developing and commercializing the drug in regions outside of the collaboration territories. Eisai will remain responsible for the manufacturing and supply of MORAb-202 globally.

Under the collaboration, BMS will pay $650 million to Eisai, including $200 million as payment toward Eisai research and development expenses. Eisai is also entitled to receive up to $2.5 billion in potential future development, regulatory, and commercial milestones.

The companies will share profits, research and development, and commercialization costs in the collaboration territories. BMS will also pay Eisai a royalty on sales outside of the collaboration territories.