 Shares of Zymeworks Inc. ZYME, rallied 14 in premarket trading on Thursday after the company and Jazz Pharmaceuticals Inc. JAZZ, -0.58 said their experimental cancer drug had an overall survival rate of 84 in patients being treated for a type of metastatic gastroesophageal adenocarcinoma after 18 months. The companies are testing zanidatamab in combination with chemotherapy as a first-line treatment in an open-label Phase 2 clinical trial. 