Gilead Sciences Inc. entered an agreement to develop and commercialize up to five cancer therapies discovered by Agenus Inc.

Gilead will pay $120 million in cash and a $30 million equity investment in exchange for the exclusive right to AGEN1423, an artificial protein that can enhance the antitumor activity of cancer treatments. Under the agreement, Lexington, Mass.-based Agenus is also eligible to receive $1.7 billion in milestone payments and fees.

AGEN1423 is a bispecific antibody, a type of protein that can bind to two different types of foreign elements that trigger an immune response. Agenus intends to request the U.S. Food and Drug Administration to start clinical trials of AGEN1423 in humans by the end of 2018.

Foster City, Calif.-based Gilead also has the option to license two additional cancer treatments, AGEN1223 and AGEN2373. Agenus will carry on developing these programs until Gilead exercises the option and can choose to share development and commercialization for one of the programs in the U.S.

Agenus has submitted an investigational new drug application for AGEN1223 and plans to submit one for AGEN2373 in the first half of 2019, allowing the company to study them in humans if approved.

Gilead also has a right of first negotiation on two undisclosed preclinical programs under the partnership agreement, which is subject to clearances and closing conditions.

The announcement comes a day after Gilead agreed to pay $80 million for first access to Scholar Rock Holding Corp.'s research to develop treatments for fibrosis, a disease that scars tissues and vital organs and can be fatal. Gilead will also make potential $1.43 billion in milestone-related payments under that agreement.