Zymeworks Appoints Suzanne Monahan as Senior Vice President, Commercial and General Manager, Theravance Biopharma

Zymeworks Inc. (Nasdaq: ZYME), a biotechnology company managing a portfolio of licensed healthcare assets while developing a diverse pipeline of novel, multifunctional biotherapeutics, today announced that Suzanne Monahan has been appointed Senior Vice President, Commercial and General Manager, Theravance Biopharma, effective immediately. asserted

Reporting directly to Kenneth Galbraith, Chair and Chief Executive Officer of Zymeworks, Ms. Monahan will lead Zymeworks’ commercial strategy and execution for YUPELRI® (revefenacin), the first and only once-daily, nebulized long-acting muscarinic antagonist (LAMA) approved in the U.S. for the maintenance treatment of chronic obstructive pulmonary disease (COPD), following the Company’s recent acquisition of Theravance Biopharma. asserted

“Suzanne is a proven commercial leader who has launched, scaled and grown products across hospital, specialty, and respiratory markets, and who knows how to build strong partnerships that deliver results,” said Kenneth Galbraith, Chair and Chief Executive Officer. asserted

“Her track record of driving sustained growth and her deep experience in market access and strategic collaborations make her ideally suited to lead our commercial efforts for YUPELRI. asserted

I am delighted to welcome her to Zymeworks. asserted

“I am thrilled to join Zymeworks at such an important time for the Company and for YUPELRI,” said Ms. Monahan. asserted

“YUPELRI is a differentiated medicine that makes a real difference for people living with COPD, and I am excited to work with the talented YUPELRI team to build on its momentum and to help more patients and providers benefit from it. asserted

I look forward to getting started.” asserted

Ms. Monahan brings more than 20 years of commercial leadership experience across the pharmaceutical and medical device industries, with expertise spanning sales, marketing, commercial operations, market access, distribution and strategic partnerships. asserted

She most recently served as Senior Vice President at Pacira BioSciences, where she was a commercial leader spanning multiple sales forces and a strategic partnerships group, and served on the joint steering and joint commercial committees governing partnered brands. asserted

Prior to Pacira, Ms. Monahan spent more than five years at Shionogi Inc., most recently as Vice President, Sales, where she led the launch of a hospital-based, IV gram-negative anti-infective and drove sustained double-digit annual growth. asserted

Earlier, as Vice President, Business Unit at Circassia Pharmaceuticals, she led a full-P&L respiratory diagnostic device business and helped partner on the relaunch of a LAMA product in the COPD market. asserted

She began her pharmaceutical career at Sanofi-Aventis and spent nine years at Salix Pharmaceuticals in roles of increasing responsibility, including National Sales Director, Institutional, Federal & Specialty Accounts. asserted

Ms. Monahan holds a B.A. in Psychology with a minor in Marketing from Quinnipiac University. asserted

About Zymeworks Inc. Zymeworks is a global biotechnology company building a diversified portfolio of healthcare assets designed to generate durable cash flows while advancing innovative medicines for difficult-to-treat diseases. asserted

The Company’s asset and royalty aggregation strategy combines a growing portfolio of commercial and near-commercial assets, including YUPELRI® (revefenacin), with a differentiated internal research and development engine. asserted

Zymeworks’ portfolio also includes Ziihera® (zanidatamab-hrii), a HER2-targeted bispecific antibody discovered and developed by Zymeworks and commercialized through global partnerships with Jazz Pharmaceuticals and BeOne Medicines, and pasritamig, a clinical-stage multispecific antibody developed by Johnson & Johnson using Zymeworks’ proprietary antibody engineering technologies. asserted

Zymeworks is advancing a diverse pipeline of novel biotherapeutics, leveraging its proprietary Azymetric™ platform and expertise in antibody-drug conjugates, multispecific antibodies and other next-generation antibody technologies. asserted

These capabilities, together with Zymeworks’ integrated drug development expertise, enable the Company to develop differentiated therapeutics and create value through both internal innovation and strategic partnerships. asserted

For more information about Zymeworks, its portfolio and pipeline, visit www.zymeworks.com and follow @ZymeworksInc on X. Cautionary Note Regarding Forward-Looking Statements This press release includes “forward-looking statements” or information within the meaning of the applicable securities legislation, including Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. asserted

Forward-looking statements in this press release include, but are not limited to, statements that relate to the anticipated benefits of the acquisition of Theravance Biopharma; the anticipated benefits of the financing in connection with the closing of the acquisition; anticipated milestones payments; Zymeworks’ ability to utilize Irish tax attributes; Zymeworks’ flexibility to invest in its R&D pipeline and pursue strategic opportunities while returning capital to stockholders; future growth of YUPELRI® sales and future royalty payments; sales and future royalty payments related to VIBATIV®; contingent milestone payments due to Theravance Biopharma from the sale of Theravance Biopharma’s TRELEGY ELLIPTA® royalty interests; the repayment of the non-recourse note issued to OMERS Life Sciences; Zymeworks’ expectations regarding implementation of its long-term strategy to maximize value creation; Zymeworks’ and its partners’ clinical development of product candidates; potential safety profile and therapeutic effects of product candidates; the commercial potential of technology platforms and product candidates; the anticipated benefits of its collaboration agreements; the Company’s 2026 full year guidance and other information that is not historical information. asserted

When used herein, words such as “plan”, “believe”, “expect”, “may”, “continue”, “anticipate”, “potential”, “will”, “on track”, “progress”, “preserve”, “intend”, “could”, and similar expressions are intended to identify forward-looking statements. uncertain

In addition, any statements or information that refer to expectations, beliefs, plans, projections, objectives, performance or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking. asserted

All forward-looking statements are based upon Zymeworks’ current expectations and various assumptions. asserted

Zymeworks believes there is a reasonable basis for its expectations and beliefs, but they are inherently uncertain. asserted

Zymeworks may not realize its expectations, and its beliefs may not prove correct. uncertain

Actual results could differ materially from those described or implied by such forward-looking statements as a result of various factors, including, without limitation: risks related to the financing in connection with the closing of the acquisition; any of Zymeworks’ or its partners’ product candidates may fail in development, may not receive required regulatory approvals, or may be delayed to a point where they are not commercially viable; uncertainties regarding the commercial success of YUPELRI®, TRELEGY and VIBATIV®; the anticipated benefits of the acquisition may not be realized or will not be realized within the expected time period; TRELEGY may not achieve anticipated sales resulting in sales milestones not being met; Zymeworks may not achieve milestones or receive additional payments or royalties under its collaborations; regulatory agencies may impose additional requirements or delay the initiation of clinical trials; the impact of new or changing laws and regulations; market conditions, including the impact of tariffs; potential negative impacts of FDA regulatory delays and uncertainty around recent policy developments, changes in the leadership of federal agencies such as the FDA, staff layoffs, budget cuts to agency programs and research, and changes in drug pricing controls; the impact of pandemics and other health crises on Zymeworks’ business, research and clinical development plans and timelines and results of operations, including impact on its clinical trial sites, collaborators, and contractors who act for or on Zymeworks’ behalf; zanidatamab may not be successfully commercialized; Zymeworks’ business strategy related to anticipated and potential future milestones and royalty streams and existing and potential new partnerships may not be successfully implemented; Zymeworks’ evolution of its business strategy may not deliver meaningful stockholder returns; Zymeworks may be unsuccessful in actively managing and/or aggregating revenue-generating assets alongside its active R&D operations; ongoing and future clinical trials may not demonstrate safety and efficacy of any of Zymeworks’ or its collaborators’ product candidates; data providing early validation of our antibody drug conjugate platform and next generation pipeline programs may not be replicated in future studies; Zymeworks’ assumptions and estimates regarding its financial condition, future financial performance and estimated cash runway may be incorrect; inability to maintain or enter into new partnerships or strategic collaborations; the inability of Zymeworks to identify and consummate a strategic acquisition; and the factors described under “Risk Factors” in Zymeworks’ quarterly and annual reports filed with the Securities and Exchange Commission (copies of which may be obtained at www.sec.gov and www.sedarplus.ca). uncertain

Although Zymeworks believes that such forward-looking statements are reasonable, there can be no assurance they will prove to be correct. asserted

Investors should not place undue reliance on forward-looking statements. asserted

Forward-looking statements are made as of the date hereof and, except as may be required by law, Zymeworks undertakes no obligation to update, republish, or revise any forward-looking statements to reflect new information, future events or circumstances, or to reflect the occurrences of unanticipated events. uncertain