 ALAMEDA, Calif., SOUTH SAN FRANCISCO, Calif. VANCOUVER, British Columbia--BUSINESS WIRE--Exelixis, Inc. Nasdaq: EXEL, Iconic Therapeutics, Inc. Iconic and Zymeworks Inc. NYSE:ZYME today announced that Exelixis has exercised its exclusive option for Iconics lead oncology antibody-drug conjugate ADC program under the companies May 2019 agreement. As a result, Exelixis now has responsibility for the future clinical development, commercialization, and manufacturing of the Tissue Facto 