FDA Grants U.S. Approval of Ziihera® (zanidatamab-hrii) for the Treatment of Adults with Previously Treated, Unresectable or Metastatic HER2-positive (IHC 3+) Biliary Tract Cancer (BTC)

FDA Grants U.S. Approval of Ziihera® (zanidatamab-hrii) for the Treatment of Adults with Previously Treated, Unresectable or Metastatic HER2-positive (IHC 3+) Biliary Tract Cancer (BTC)

VANCOUVER, British Columbia, Oct. 21, 2024 (GLOBE NEWSWIRE) -- Zymeworks Inc. (Nasdaq: ZYME), a clinical-stage biotechnology company developing a diverse pipeline of novel, multifunctional biotherapeutics to improve the standard of care for difficult-to-treat diseases, today announced that the first patient has been dosed in the first-in-human Phase 1 trial (NCT06523803) to evaluate the safety and tolerability of the investigational therapy ZW171 in the treatment of advanced or metastatic ovarian cancer, NSCLC, and other MSLN-expressing cancers.

MSLN has strong expression in a broad number of tumor indications, including ovarian cancer (~84%1), with moderate to strong expression in NSCLC (~36%1), making it an appealing target for therapeutic development with our proprietary T cell engager technology. In preclinical studies, ZW171 has demonstrated in vivo potent preferential killing of MSLN-overexpressing target cells and stimulation MSLN-dependent T cell activation, mitigating the risk of on-target-off tumor toxicity and peripheral T cell activation and cytokine release syndrome.

Data presented at the American Association for Cancer Research Annual Meeting in 2023 demonstrated that ZW171 exhibits greater anti-tumor activity compared to benchmark in MSLN-expressing tumor models and is well tolerated in cynomolgus monkeys up to 30 mg/kg2.

“We are very pleased to have initiated the clinical evaluation of ZW171 for the treatment of patients with ovarian cancer and NSCLC, where it has the potential to be a highly effective therapy with favorable tolerability based on our preclinical research results,” said Jeff Smith, M.D., FRCP, Executive Vice President and Chief Medical Officer at Zymeworks. “Initiation of this trial marks a significant step forward in our effort to bring a potential new treatment to people living with difficult to treat cancers and highlights our goal to advance two therapeutic candidates, ZW171 and ZW191, into clinical studies in 2024.”

The Phase 1 study is a two-part, open-label multi-center study that is expected to enroll approximately 160 adult patients with advanced MSLN-expressing cancers. Part 1 of the study will evaluate the safety and tolerability of ZW171 and involve dose escalation in patients with advanced ovarian and NSCLC, with secondary endpoints assessing pharmacokinetics and confirmed objective response rate. Part 2 of the study will involve dose expansion in three cohorts (ovarian cancer, NSCLC, and a basket cohort enrolling patients with any MSLN-expression) and will evaluate the anti-tumor activity of ZW171, with primary endpoints focused on safety and tolerability and secondary endpoints assessing progression-free survival, duration of response rates, and overall survival. The Company expects to conduct the Phase 1 study at investigator sites in the United States, Europe, and the Asia-Pacific region.

“We are also encouraged by the levels of interest in ZW171, which represents a promising and differentiated approach in the treatment of advanced mesothelin-expressing cancers,” Dr. Smith added, noting, “Our trial is designed to rapidly generate clinical data on our differentiated product profile relative to other mesothelin-expressing therapeutics in clinical development.”

About ZW171

ZW171 is a bispecific antibody designed to enable T cell-mediated tumor cell killing through simultaneous binding to the extracellular domain of MSLN protein on tumor cells and the engagement of CD3 on T cells. Moderate to high membranous MSLN expression is frequent in ovarian cancer, non-small cell lung cancer, mesothelioma and other cancers3. Preliminary evidence of anti-tumor activity with engineered T-cell therapy supports utility of T-cell targeted therapies in treatment of MSLN-expressing solid tumors4. ZW171’s unique 2+1 format and incorporation of a novel low-affinity anti-CD3 binder aims to improve the therapeutic window in patients by limiting on-target, off-tumor effects and cytokine release syndrome (CRS) while maintaining potent anti-tumor activity against MSLN-expressing cancers5. By selectively binding to tumors and sparing normal tissues, ZW171 is designed to improve both tolerability and anti-tumor activity against MSLN-expressing cancers. Engineered using our Azymetric™ and EFECT™2 technologies, ZW171 demonstrates enhanced anti-tumor activity and safety in preclinical models, inducing potent, preferential killing of MSLN-overexpressing cells while mitigating the risk of on-target, off-tumor activity, peripheral T cell activation, and CRS.

VANCOUVER, British Columbia, Nov. 21, 2024 (GLOBE NEWSWIRE) -- Zymeworks Inc. (Nasdaq: ZYME), a clinical-stage biotechnology company developing a diverse pipeline of novel, multifunctional biotherapeutics to improve the standard of care for difficult-to-treat diseases, today announced, with Jazz Pharmaceuticals, that the U.S. Food and Drug Administration (FDA) has granted accelerated approval of Ziihera® (zanidatamab-hrii) 50mg/mL for injection for intravenous use for the treatment of adults with previously-treated, unresectable or metastatic HER2-positive (IHC 3+) biliary tract cancer (BTC), as detected by an FDA-approved test.1 Ziihera was approved under accelerated approval based on a 52% objective response rate (ORR) and a median duration of response (DOR) of 14.9 months as determined by independent central review (ICR). Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.1 The approval of Ziihera, which previously received Breakthrough Therapy Designation from the FDA for this indication, is an important advance and offers the first and only dual HER2-targeted bispecific antibody and chemotherapy-free treatment for patients living with BTC.

In late 2022, Zymeworks entered into a license and collaboration agreement with Jazz Pharmaceuticals Ireland Limited (a subsidiary of Jazz Pharmaceuticals plc, collectively referred to as Jazz), for the exclusive development and commercialization rights to zanidatamab across all indications in the United States, Europe, Japan and all other territories except for those Asia Pacific territories previously licensed by Zymeworks. This collaboration allowed the Company to leverage Jazz’s global commercial infrastructure, together with BeiGene’s complementary strengths in certain Asia Pacific countries, to enable the global, rapid advancement of zanidatamab in multiple tumor types with the potential to provide a foundational HER2-targeted therapy for patients with difficult-to-treat cancers and limited treatment options. Under the terms of the Jazz license and collaboration agreement, Zymeworks has earned a milestone payment of $25M based on the FDA approval in BTC. Zymeworks is also eligible to receive up to a further $500M in regulatory milestone payments and $862.5M in commercial milestone payments, as well as tiered royalties of 10% to 20% of net sales by Jazz.

This approval represents the first FDA-approved therapy in Zymeworks’ pipeline, and validates the Company’s novel Azymetric™ bispecific platform technology and internal research and development capabilities for novel multifunctional medicines.

“The FDA’s accelerated approval of Ziihera marks the culmination of more than a decade of research and development at Zymeworks, highlighting our deep scientific expertise in multifunctional biotherapeutics and unwavering commitment to innovation in drug development,” said Paul Moore, Ph.D., Chief Scientific Officer at Zymeworks. “This approval exemplifies our team’s exceptional scientific capabilities to translate from an initial hypothesis for dual-HER2 blockade to a breakthrough treatment that offers new hope for patients with unresectable or metastatic HER2-positive BTC with limited treatment options and few approved therapies.”

Through rigorous scientific investigation, innovative protein engineering, and proprietary Azymetric™ bispecific platform technology, Zymeworks developed the unique binding mechanism of zanidatamab-hrii, which enables it to bind to two extracellular sites on HER2. Binding of zanidatamab-hrii with HER2 results in internalization leading to a reduction of the receptor on the tumor cell surface. Zanidatamab-hrii induces complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). These mechanisms result in tumor growth inhibition and cell death in vitro and in vivo.

The FDA approval of Ziihera is based on compelling data from the HERIZON-BTC-01 trial, which included the evaluation of zanidatamab as a single agent in previously treated HER2-positive (as determined by Roche Diagnostic’s PATHWAY® anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody companion diagnostic) BTC and is the largest Phase 2b clinical trial to date specifically for this patient population. The trial achieved its primary endpoint of confirmed objective response rate (cORR) by independent central review (ICR) and results were presented at the American Society of Clinical Oncology (ASCO) Annual Meeting 2023, published in The Lancet Oncology, and included in the 2023 Best of ASCO® program. Longer follow-up data showing improvement upon previously reported DOR were reported at the ASCO Annual Meeting 2024.1

The Phase 3 HERIZON-BTC-302 confirmatory trial is ongoing to evaluate zanidatamab in combination with standard-of-care therapy versus standard-of-care therapy alone in the first-line setting for patients with HER2-positive BTC. Zanidatamab is also being investigated in a number of additional tumor types, including Phase 3 trials in gastroesophageal adenocarcinomas (GEAs) and metastatic breast cancer (mBC). The HERIZON-GEA-01 trial is evaluating the potential of zanidatamab plus chemotherapy with or without tislelizumab as first-line treatment for patients with advanced/metastatic HER2-positive GEAs and top-line progression-free survival data from this study is expected to be available in Q2-2025. The EmpowHER-303 trial is evaluating the potential of zanidatamab in combination with physician’s choice chemotherapy for the treatment of HER2-positive mBC for patients who have progressed on, or are intolerant to, previous trastuzumab deruxtecan treatment.

“Our strategic collaboration with Jazz provided the optimal ‘partner of choice’ to continue the rapid advancement of zanidatamab, and we are extremely encouraged with Jazz’s continued investment in and dedication to the development and commercialization of this novel therapy within their geographic territories,” said Kenneth Galbraith, Chair and Chief Executive Officer of Zymeworks. “The combination of our strong balance sheet and anticipated revenue stream associated with zanidatamab positions us to accelerate the development of our wholly-owned R&D programs, while maintaining our projected cash runway into the second half of 2027.”

Zymeworks continues to advance a diverse pipeline of novel therapeutics targeting difficult-to-treat cancers and other serious diseases, with several product candidates in various stages of development. The Company’s in-house research and development capabilities, which were instrumental in zanidatamab’s success, remain focused on delivering the next generation of innovative treatments. Zymeworks will host an in-person and virtual R&D day in New York on December 12, 2024, which will feature updates on the Company’s portfolio of solid tumor targeting antibody-drug conjugates and T cell engager molecules, including preclinical progress supporting potential investigational new drug applications for multiple new product candidates in 2025, 2026 and beyond, and strategy and rationale for potential expansion into new therapeutic areas in hematological cancers and autoimmune and inflammatory diseases.

More information about Ziihera, the Full Prescribing Information, including Boxed Warning and Patient Information, is available here.

About Zymeworks Inc. 

Zymeworks is a global clinical-stage biotechnology company committed to the discovery, development, and commercialization of novel, multifunctional biotherapeutics. Zymeworks’ mission is to make a meaningful difference in the lives of people impacted by difficult-to-treat cancers and other diseases. The Company’s complementary therapeutic platforms and fully integrated drug development engine provide the flexibility and compatibility to precisely engineer and develop highly differentiated antibody-based therapeutic candidates. Zymeworks engineered and developed zanidatamab, a HER2-targeted bispecific antibody using the Company’s proprietary Azymetric™ technology. Zymeworks has entered into separate agreements with BeiGene, Ltd. (BeiGene) and Jazz Pharmaceuticals Ireland Limited (Jazz), granting each exclusive rights to develop and commercialize zanidatamab in different territories. Zanidatamab is currently being evaluated in multiple global clinical trials as a potential best-in-class treatment for patients with HER2-expressing cancers. The U.S. FDA granted accelerated approval of Ziihera® (zanidatamab-hrii) 50mg/mL for injection for intravenous use for the treatment of adults with previously-treated, unresectable or metastatic HER2-positive (IHC 3+) biliary tract cancer (BTC). Ziihera is the first and only dual HER2-targeted bispecific antibody approved for HER2-positive BTC in the U.S. A BLA has also been accepted for review by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) in China. Zymeworks is rapidly advancing a robust pipeline of wholly-owned product candidates, leveraging its expertise in both antibody-drug conjugates and multispecific antibody therapeutics targeting novel pathways in areas of significant unmet medical need. Phase 1 studies for ZW171 and ZW191 are now actively recruiting with investigational new drug applications for ZW220 and ZW251 planned for 2025. In addition to Zymeworks’ pipeline, its therapeutic platforms have been further leveraged through strategic partnerships with global biopharmaceutical companies. For information about Zymeworks, visit www.zymeworks.com and follow @ZymeworksInc on X.

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. Forward-looking statements in this press release include, but are not limited to, statements that relate to the conduct of an ongoing HERIZON-BTC-302 Phase 3 confirmatory trial to evaluate the efficacy and safety of zanidatamab and support global registration; ongoing clinical studies and regulatory reviews; the anticipated benefits of the collaboration agreements with Jazz and BeiGene, including Zymeworks’ ability to receive any future milestone payments and royalties thereunder; the potential addressable market of zanidatamab; the timing of and results of interactions with regulators; Zymeworks’ clinical development of its product candidates and enrollment in its clinical trials; the timing and status of ongoing and future studies and the related data; expectations regarding future regulatory filings and approvals and the timing thereof; potential safety profile and therapeutic effects of zanidatamab and Zymeworks’ other product candidates; the commercial potential of technology platforms and product candidates; Zymeworks’ ability to satisfy potential regulatory and commercial milestones with existing and future partners; anticipated continued receipt of revenue from existing and future partners; anticipated sufficiency of existing cash resources and certain anticipated revenues from zanidatamab to fund Zymeworks’ planned operations into the second half of 2027; Zymeworks’ ability to execute new collaborations and partnerships and other information that is not historical information. When used herein, words such as “plan”, “believe”, “expect”, “may”, “anticipate”, “potential”, “will”, “continues”, 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: 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; Zymeworks may not achieve milestones or receive additional payments 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; 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; clinical trials and any future clinical trials may not demonstrate safety and efficacy of any of Zymeworks’ or its collaborators’ product candidates; Zymeworks’ assumptions and estimates regarding its financial condition, future financial performance and estimated cash runway may be incorrect; and Zymeworks may be unable to maintain or enter into new partnerships or strategic collaborations.

Although Zymeworks believes that such forward-looking statements are reasonable, there can be no assurance they will prove to be correct. Investors should not place undue reliance on forward-looking statements. The above assumptions, risks and uncertainties are not exhaustive. 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.

Contacts:

Investor Inquiries:

Shrinal Inamdar
Director, Investor Relations
(604) 678-1388 
ir@zymeworks.com   

Media Inquiries:

Diana Papove
Senior Director, Corporate Communications
(604) 678-1388 
media@zymeworks.com

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