U.S. FDA Grants Priority Review to BeOne Medicines' TEVIMBRA in First-Line HER2+ GEA

TEVIMBRA plus ZIIHERA and chemotherapy regimen delivered statistically significant median OS of 26.4 months, an unprecedented result in this challenging disease

Results from the global Phase 3 HERIZON-GEA-01 study demonstrate potential to change clinical practice in advanced HER2+ gastroesophageal adenocarcinoma

BeOne Medicines Ltd. (NASDAQ:ONC, HKEX: 06160, SSE: 688235)), a global oncology company, today announced that the U.S. Food and Drug Administration (FDA) has granted Priority Review to a supplemental Biologics License Application (sBLA) for TEVIMBRA^® (tislelizumab) in combination with ZIIHERA^® (zanidatamab) and chemotherapy for the first-line treatment of unresectable locally advanced/metastatic HER2-positive (HER2) gastric, gastroesophageal junction, or esophageal adenocarcinoma. The FDA has also granted Breakthrough Therapy Designation to the regimen of ZIIHERA in combination with fluoropyrimidine- and platinum-containing chemotherapy, with and without TEVIMBRA, in this indication.

Mark Lanasa, M.D., Ph.D., Chief Medical Officer, Solid Tumors, BeOne Medicines, said:

"HERIZON‑GEA‑01 has the potential to shift the treatment paradigm in this historically difficult-to-treat disease, with the TEVIMBRA-containing arm demonstrating an unprecedented 26-month survival benefit. The FDA's Priority Review designation is a major milestone in our effort to bring better first‑line options to patients with HER2‑positive gastroesophageal adenocarcinoma. We will work in partnership with regulators to support the review process, with the aim of rapidly bringing this new treatment option to patients."

Data supporting sBLA filing

The sBLA submission is based on the first interim analysis (IA1) of HERIZON-GEA-01, a global Phase 3 clinical trial designed to evaluate ZIIHERA plus chemotherapy, with and without TEVIMBRA, compared with the control arm of trastuzumab plus chemotherapy as first-line treatment for advanced/metastatic HER2+ GEA. Key findings of the trial include:

• Overall survival (OS): The arm in which TEVIMBRA was added to ZIIHERA and chemotherapy resulted in a statistically significant improvement in OS (median OS of 26.4 months) at IA1. The ZIIHERA plus chemotherapy arm achieved a median OS of 24.4 months and the control arm resulted in a median OS of 19.2 months.
• Progression-free survival (PFS): Both ZIIHERA-containing arms delivered a statistically significant and clinically meaningful improvement in median PFS of 12.4 months compared with 8.1 months in the control arm.
• Improvement in OS and PFS was observed regardless of PD-L1 status.
• The safety findings for the ZIIHERA plus TEVIMBRA and chemotherapy arm were generally consistent with the known effects of the components of the combination regimen, and no new safety signals were identified.

Project Orbis pathway

BeOne plans to participate in the FDA's Project Orbis, an initiative that provides a framework for collaborative review of oncology products among international partners, for the submission of the HERIZON-GEA-01 data in territories in which BeOne holds the ZIIHERA license. With this pathway, BeOne aims to accelerate approval and patient access to this treatment, recognizing the global significance of the HERIZON‑GEA‑01 results, which demonstrated meaningful survival improvements in a disease where outcomes have remained largely unchanged for more than a decade.

About the HERIZON-GEA-01 Phase 3 Trial

HERIZON-GEA-01 (NCT05152147) is a global, randomized, open-label Phase 3 trial, conducted jointly with Jazz Pharmaceuticals, to evaluate and compare the efficacy and safety of ZIIHERA plus chemotherapy, with and without TEVIMBRA, to the standard of care (trastuzumab plus chemotherapy) as first-line treatment for adult patients with advanced/metastatic HER2+ GEA. The trial randomized 914 patients from approximately 300 trial sites in more than 30 countries. Patients for this trial had unresectable locally advanced, recurrent or metastatic HER2+ GEA (adenocarcinomas of the stomach or esophagus, including the gastroesophageal junction), defined as 3+ HER2 expression by IHC or 2+ HER2 expression by IHC with ISH positivity per central assessment. Patients were randomized to the three trial arms: ZIIHERA in combination with chemotherapy and TEVIMBRA; ZIIHERA in combination with chemotherapy; and trastuzumab plus chemotherapy. The trial is evaluating dual primary endpoints, PFS per blinded independent central review (BICR) and OS.

About Gastroesophageal Adenocarcinoma

Gastroesophageal adenocarcinoma (GEA), which includes cancers of the stomach, gastroesophageal junction, and esophagus, is the fifth most common cancer worldwide. Approximately 20% of GEA patients have HER2-positive disease^1,2,3, which has high morbidity and mortality, and patients are urgently in need of new treatment options. The overall prognosis for patients with GEA remains poor, with a global five-year survival rate of less than 30% for gastric cancer and about 19% for GEA.⁴

About ZIIHERA (zanidatamab)

ZIIHERA (zanidatamab) is a bispecific human epidermal growth factor receptor 2, or HER2-directed antibody that binds to two extracellular sites on HER2. Binding of zanidatamab with HER2 results in internalization leading to a reduction in HER2 expression of the receptor on the tumor cell surface. Zanidatamab 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.⁵

Zanidatamab is being developed in multiple clinical trials as a targeted treatment option for patients with solid tumors that express HER2. Zanidatamab is approved in China for the treatment of patients who have unresectable, locally advanced, or metastatic HER2-high expression (IHC 3+) biliary tract cancer (BTC) and who have received prior systemic therapy. ZIIHERA has also been granted accelerated approval in the U.S. and conditional marketing authorization in the European Union for eligible BTC patients. Zanidatamab is being developed by Jazz and BeOne under license agreements from Zymeworks, which first developed the molecule. BeOne has licensed zanidatamab from Zymeworks in Asia (excluding India and Japan), Australia and New Zealand. Jazz Pharmaceuticals has rights in all other regions.

ZIIHERA is a registered trademark of Zymeworks BC Inc.

About TEVIMBRA (tislelizumab)

TEVIMBRA is a uniquely designed humanized immunoglobulin G4 (IgG4) anti-programmed cell death protein 1 (PD-1) monoclonal antibody with high affinity and binding specificity against PD-1. It is designed to minimize binding to Fc-gamma (Fcγ) receptors on macrophages, helping to aid the body's immune cells to detect and fight tumors.

TEVIMBRA is the foundational asset of BeOne's solid tumor portfolio and has shown potential across multiple tumor types and disease settings. The global TEVIMBRA clinical development program includes more than 15,000 patients enrolled to date in 30+ countries and regions across 72 trials, including 22 registration-enabling studies. TEVIMBRA is approved in 50 countries, and more than 1.9 million patients have been treated globally.

Select Important Safety Information

Serious and sometimes fatal adverse reactions occurred with TEVIMBRA treatment. Warnings and precautions include severe and fatal immune-mediated adverse reactions, including pneumonitis, colitis, hepatitis, endocrinopathies, dermatologic adverse reactions, nephritis with renal dysfunction, and solid organ transplant rejection. Other warnings and precautions include infusion-related reactions, complications of allogeneic HSCT, and embryo-fetal toxicity.

Please see full U.S. Prescribing Information including the U.S. Medication Guide.

The information in this press release is intended for a global audience. Product indications vary by region.

About BeOne

BeOne Medicines is a global oncology company that is discovering and developing innovative treatments for cancer patients worldwide. With a portfolio spanning hematology and solid tumors, BeOne is expediting development of its diverse pipeline of novel therapeutics through its internal capabilities and collaborations. The Company has a growing global team spanning six continents who are driven by scientific excellence and exceptional speed to reach more patients than ever before. To learn more about BeOne, please visit www.beonemedicines.com and follow us on LinkedIn, X, Facebook and Instagram.

Forward-Looking Statement

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and other federal securities laws, including statements regarding the potential benefits of ZIIHERA and TEVIMBRA; the potential of TEVIMBRA plus ZIIHERA and chemotherapy to shift the treatment paradigm in first-line HER2-positive metastatic GEA; the potential opportunity to expand access; BeOne's expectations regarding ZIIHERA's and TEVIMBRA's clinical development and regulatory milestones; BeOne's plans to submit the data for publication; and BeOne's plans, commitments, aspirations, and goals under the heading "About BeOne." Actual results may differ materially from those indicated in the forward-looking statements as a result of various important factors, including BeOne's ability to demonstrate the efficacy and safety of its drug candidates; the clinical results for its drug candidates, which may not support further development or marketing approval; actions of regulatory agencies, which may affect the initiation, timing, and progress of clinical trials and marketing approval; BeOne's ability to achieve commercial success for its marketed medicines and drug candidates, if approved; BeOne's ability to obtain and maintain protection of intellectual property for its medicines and technology; BeOne's reliance on third parties to conduct drug development, manufacturing, commercialization, and other services; BeOne's limited experience in obtaining regulatory approvals and commercializing pharmaceutical products and its ability to obtain additional funding for operations and to complete the development of its drug candidates and achieve and maintain profitability; and those risks more fully discussed in the section entitled "Risk Factors" in BeOne's most recent quarterly report on Form 10-Q, as well as discussions of potential risks, uncertainties, and other important factors in BeOne's subsequent filings with the U.S. Securities and Exchange Commission. All information in this press release is as of the date of this press release, and BeOne undertakes no duty to update such information unless required by law.

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