Zymeworks Inc. (ZYME) SEC Filing 10-Q Quarterly report for the period ending Tuesday, March 31, 2020

Exhibit 99.1

Zymeworks Reports 2019 Year-End Financial Results

Vancouver, Canada (March 2, 2020)

“We’ve started the year off strong thanks to significant clinical progress in the second half of 2019 and a recent financing that has provided expanded resources to further advance global development of our clinical candidates, ZW25 and ZW49,” said Ali Tehrani, Ph.D., Zymeworks’ President & CEO. “We plan to initiate registration-enabling studies for ZW25 in both biliary tract and gastric cancer, as well as explore additional indications, with a vision toward establishing ZW25 as the new foundational HER2 therapy. We also remain confident in the potential of ZW49 to be transformative in refractory and low HER2-expressing cancers and expect to begin expansion cohorts later this year.”

2019 Business Highlights and Recent Developments

In January 2020, Zymeworks completed an upsized US$320.8 million public financing to accelerate and expand global development of its lead clinical candidates, ZW25 and ZW49, and support further advancement of its novel preclinical programs.

ZW25 has been well tolerated and has demonstrated promising anti-tumor activity both as a single agent and in combination with chemotherapy, supporting the planned initiation of two registration-enabling trials in refractory HER2-positive biliary tract cancer and first-line HER2-positive gastroesophageal adenocarcinomas. In addition, Zymeworks recently initiated a Phase 2 trial and collaboration with Pfizer to evaluate ZW25 in combination with palbociclib and fulvestrant in HER2-positive, hormone receptor-positive breast cancer.

Zymeworks’ second product candidate, ZW49, began a Phase 1 clinical trial to evaluate safety and anti-tumor activity, and to establish a recommended dose and schedule for expansion cohorts. A recent update highlighted that there had been no dose-limiting toxicities observed and the maximum tolerated dose had not been reached. The majority of treatment-related adverse events were grade 1 or 2, and were reversible and manageable on an outpatient basis. Preliminary results from these initial dose cohorts included anti-tumor activity.

In 2019, Eli Lilly entered the clinic with a novel bispecific; Merck, Celgene (now BMS), and Daiichi Sankyo advanced bispecific candidates toward clinical testing; GSK expanded its Azymetric^™ partnership; and the first ZymeLink ADC collaboration was signed with Iconic Therapeutics. Zymeworks currently has nine active collaborations that offer up to US$7.9 billion in potential milestone payments as well as royalties on potential product sales.