Zymeworks Opens Phase 2 Clinical Trial for ZW25 in First-Line HER2-Expressing Metastatic Gastroesophageal Cancers

April 15, 2019 Off By BusinessWire

VANCOUVER, British Columbia–(BUSINESS WIRE)–Zymeworks Inc. (NYSE/TSX: ZYME), a clinical-stage biopharmaceutical
company developing multifunctional therapeutics, today announced it has
initiated its global multicenter Phase 2 clinical trial evaluating ZW25
in combination with standard of care chemotherapy for the first-line
treatment of HER2-positive metastatic gastric, gastroesophageal
junction, and esophageal adenocarcinomas.

“Advancing ZW25 into a Phase 2 clinical trial represents another key
milestone for Zymeworks,” said Ali Tehrani, Ph.D., Zymeworks’ President
& CEO. “This reaffirms our commitment to execute our ambitious drug
development strategy to address unmet need in patients with
HER2-expressing cancers across multiple indications and lines of
therapy. We anticipate that data from this trial will support initiation
of a first-line registrational trial, which could position ZW25 as the
new standard of care for HER2-positive metastatic gastric cancer.”

In addition to the Phase 2 metastatic gastroesophageal cancer trial,
ZW25 continues to be evaluated in multiple expansion cohorts in the
ongoing Phase 1 trial as a single agent in gastrointestinal,
gynecological, and other HER2-expressing cancers, and in combination
with chemotherapy in breast and gastroesophageal cancers.

About the Trial

The Phase 2 trial is a two-part open-label study. The primary objectives
of this trial are to confirm the safety, tolerability, and anti-tumor
activity of ZW25 in combination with global standard of care regimens
for gastroesophageal adenocarcinoma, including platinum and
fluoropyrimidine-based regimens.

“While major advances have been made in the treatment of HER2-positive
breast cancer, patients with HER2-positive gastroesophageal
adenocarcinomas still have limited options,” said Diana Hausman, M.D.,
Chief Medical Officer of Zymeworks. “Based on the encouraging single
agent anti-tumor activity we observed in patients with gastroesophageal
adenocarcinomas in our Phase 1 study, we believe that ZW25 has the
potential to address this need, and we are excited to be starting this
first-line trial.”

About ZW25

ZW25 is being evaluated in Phase 1 and Phase 2 clinical trials across
North America and South Korea. It is a bispecific antibody, based on
Zymeworks’ Azymetric™ platform, that can simultaneously bind two
non-overlapping epitopes of HER2, known as biparatopic binding. This
unique design results in multiple mechanisms of action including dual
HER2 signal blockade, increased binding and removal of HER2 protein from
the cell surface, and potent effector function leading to encouraging
anti-tumor activity in patients. Zymeworks is developing ZW25 as a
HER2-targeted treatment option for patients with any solid tumor that
expresses HER2. The FDA has granted Orphan Drug Designation to ZW25 for
the treatment of both gastric and ovarian cancers.

About the Azymetric™ Platform

The Azymetric platform enables the transformation of monospecific
antibodies into bispecific antibodies, giving the antibodies the ability
to simultaneously bind two different targets. Azymetric bispecific
technology enables the development of multifunctional biotherapeutics
that can block multiple signaling pathways, recruit immune cells to
tumors, enhance receptor clustering degradation, and increase
tumor-specific targeting. These features are intended to enhance
efficacy while reducing toxicities and the potential for
drug-resistance. Azymetric bispecifics have been engineered to retain
the desirable drug-like qualities of naturally occurring antibodies,
including low immunogenicity, long half-life, and high stability. In
addition, they are compatible with standard manufacturing processes with
high yields and purity, potentially significantly reducing drug
development costs and timelines.

About Zymeworks Inc.

Zymeworks is a clinical-stage biopharmaceutical company dedicated to the
development of next-generation multifunctional biotherapeutics. The
Company’s suite of therapeutic platforms and its fully integrated drug
development engine enable precise engineering of highly differentiated
product candidates. Zymeworks’ lead clinical candidate, ZW25, is a novel
Azymetric™ bispecific antibody currently in Phase 2 clinical
development. The Company’s second clinical candidate, ZW49, is a
bispecific antibody-drug conjugate currently in Phase 1 clinical
development and combines the unique design and antibody framework of
ZW25 with Zymeworks’ proprietary ZymeLink™ cytotoxic payload. Zymeworks
is also advancing a deep preclinical pipeline in immuno-oncology and
other therapeutic areas. In addition, its therapeutic platforms are
being leveraged through multiple strategic partnerships with eight
global biopharmaceutical companies. For more information, visit www.zymeworks.com.

Cautionary Note Regarding Forward-Looking Statements

This press release includes “forward-looking statements” within the
meaning of the U.S. Private Securities Litigation Reform Act of 1995 and
“forward-looking information” within the meaning of Canadian securities
laws, or collectively, forward-looking statements. Forward-looking
statements in this news release include, but are not limited to,
statements that relate to clinical trials of ZW25, ZW25’s potential for
treatment of certain cancers and other information that is not
historical information. When used herein, words and phrases such as
“will,” “potential to,” and similar expressions are intended to identify
forward-looking statements. 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. All forward-looking statements are based upon
Zymeworks’ current expectations and various assumptions. Zymeworks
believes there is a reasonable basis for its expectations and beliefs,
but they are inherently uncertain. Zymeworks may not realize its
expectations, and its beliefs may not prove correct. Actual results
could differ materially from those described or implied by such
forward-looking statements as a result of various factors, including,
without limitation, market conditions and the factors described under
“Risk Factors” in Zymeworks’ Annual Report on Form 10-K for its fiscal
year ended December 31, 2018 (a copy of which may be obtained at www.sec.gov
and www.sedar.com).
Consequently, forward-looking statements should be regarded solely as
Zymeworks’ current plans, estimates and beliefs. Investors should not
place undue reliance on forward-looking statements. Zymeworks cannot
guarantee future results, events, levels of activity, performance or
achievements. Zymeworks does not undertake and specifically declines any
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, except as may be
required by law.

Contacts

Zymeworks Inc.
Investor
Inquiries:

Ryan Dercho, Ph.D.
(604) 678-1388
[email protected]
Tiffany
Tolmie
(604) 678-1388
[email protected]
Media
Inquiries:

Angela Bitting
(925) 202-6211
[email protected]