 VANCOUVER, British Columbia--BUSINESS WIRE--Zymeworks Inc. NYSE: ZYME, a clinical-stage biopharmaceutical company developing multifunctional biotherapeutics, today announced that the U.S. Food and Drug Administration FDA has granted Breakthrough Therapy designation for zanidatamab in patients with previously-treated HER2 gene-amplified biliary tract cancer BTC. The FDA grants Breakthrough Therapy designation to new medicines that are intended to treat a serious condition and where clini 