Gastroesophageal junction adenocarcinoma

In 2024, the field of cancer therapeutics has witnessed remarkable progress in targeting Claudin 18.2 (CLDN18.2). As a protein highly expressed in several malignancies—particularly gastrointestinal cancers such as gastric and pancreatic cancer—CLDN18.2 has emerged as a highly promising therapeutic target. Antibody-drug conjugates (ADCs) developed against this target, including Zolbetuximab, IBI-343, LM-302, and SHR-A1904, have shown encouraging preclinical and clinical results. These innovations not only improve patient survival but also pave the way for more personalized treatment approaches. By selectively recognizing and attacking tumor cells while minimizing damage to normal tissues, these agents are redefining the landscape of cancer therapy. CLDN18.2 is an isoform of Claudin-18, which belongs to the Claudin family of proteins. This family comprises transmembrane proteins that play crucial roles in maintaining tight junctions between epithelial and endothelial cells. Tight junctions function as both physical barriers, preventing the free passage of substances through the paracellular space, and as regulators of ion and small molecule permeability. The depiction of Claudin protein structures1 Structurally, Claudins share common features, including four transmembrane domains, two extracellular loops (ECL1 and ECL2), and intracellular N- and C-termini. CLDN18.2 is predominantly expressed in differentiated epithelial cells of the gastric mucosa, exhibiting highly specific expression under normal physiological conditions. However, during malignant transformation, the disruption of tight junctions caused by uncontrolled tumor proliferation can expose CLDN18.2 epitopes, making them accessible for targeted therapeutic intervention. Main characteristics of claudins2 From a proliferation perspective, evidence suggests that CLDN18.2 may interfere with intercellular communication and signal transduction pathways, influencing the cell cycle and promoting tumor growth. High expression of CLDN18.2 has been associated with increased tumor cell proliferation in several studies, likely due to its role in maintaining cell polarity and regulating cell growth. In terms of invasion and metastasis, abnormal activation of the CLDN18.2 gene may alter cell membrane functionality and enhance tissue permeability. This disruption facilitates tumor cells in breaching the basement membrane and invading surrounding tissues, thus promoting both local and distant metastases. Aberrant CLDN18.2 expression also impairs normal cell polarity and structural integrity, further weakening tissue barriers and enabling cancer cell dissemination. While CLDN18.2 expression is typically confined to gastric mucosal cells under normal conditions, it is significantly upregulated in various cancers, including gastric and pancreatic cancers. This persistent expression even after malignant transformation, combined with exposure of the epitope due to tight junction disruption, makes CLDN18.2 an attractive target for antibody-based therapies, particularly in cancers with limited treatment options. ADC Therapies Targeting CLDN18.2Zolbetuximab: The First Approved CLDN18.2-Targeted Monoclonal AntibodyZolbetuximab is the first globally approved therapeutic specifically targeting CLDN18.2. It is a chimeric IgG1 monoclonal antibody designed for the treatment of gastric and gastroesophageal junction (GEJ) adenocarcinomas. By binding selectively to CLDN18.2, a transmembrane protein highly expressed on certain gastric cancer cells, Zolbetuximab induces direct cancer cell death. Moreover, it activates two major immune-mediated mechanisms: antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). ADCC involves the recruitment of immune effector cells, such as natural killer (NK) cells, to the tumor site, leading to targeted destruction of cancer cells.CDC triggers the complement system to form membrane attack complexes (MACs) that lyse tumor cells.The development of Zolbetuximab was underpinned by its successful performance in two pivotal Phase III clinical trials—SPOTLIGHT and GLOW. In the SPOTLIGHT trial, Zolbetuximab combined with mFOLFOX6 chemotherapy significantly improved progression-free survival (PFS) and overall survival (OS) compared to chemotherapy alone: Median PFS: 10.61 months vs. 8.67 monthsMedian OS: 18.23 months vs. 15.54 monthsSimilarly, the GLOW trial demonstrated that Zolbetuximab combined with CAPOX chemotherapy also yielded superior outcomes compared to CAPOX alone. Based on these positive results, Zolbetuximab has received regulatory approval in multiple countries and regions, including Japan, the United States, and the European Union, for the treatment of specific subtypes of gastric cancer. It remains the first and only approved CLDN18.2-targeted therapy to date. Although initially developed for gastric and GEJ adenocarcinomas, Zolbetuximab’s therapeutic potential could extend to other malignancies, such as pancreatic, biliary tract, esophageal, and lung cancers, where CLDN18.2 expression is also elevated. Expression testing is typically required to identify patients who are most likely to benefit from Zolbetuximab therapy. As understanding of CLDN18.2 biology deepens, it is anticipated that Zolbetuximab could be explored in combination strategies, such as with immune checkpoint inhibitors or other targeted therapies, to further enhance efficacy and reduce adverse effects. Additionally, the success of Zolbetuximab has catalyzed the development of next-generation CLDN18.2-targeted agents, promising new hope for patients with limited treatment options. These advances are expected to significantly contribute to the evolution of personalized cancer care, enabling more precise, effective, and individualized therapeutic strategies. Bispecific Antibody LB-4330LB-4330 is a bispecific antibody developed by L&L Biopharma, designed to leverage its dual-targeting capability to activate CD8+ T cells within the tumor microenvironment, thereby enhancing the body's immune response against cancer. By doing so, LB-4330 not only directly attacks cancer cells but also mobilizes the patient’s immune system for a more effective and sustained anti-tumor response. The mechanism of action of LB-4330 relies on its unique structural design, which enables simultaneous binding to CLDN18.2 and specific receptors on the surface of CD8+ T cells. This dual specificity allows LB-4330 to accumulate at tumor sites and activate T cells, triggering the release of cytotoxic substances to kill cancer cells. Moreover, LB-4330 may also enhance anti-tumor immunity through additional, less well-characterized mechanisms, such as modifying the tumor microenvironment or improving dendritic cell function. These features position LB-4330 as a promising therapeutic candidate, particularly for patients with advanced or metastatic cancers that are resistant to conventional treatments. The major CD8+ T cell states in human tumors3 Currently, LB-4330 is in Phase II clinical development, focusing on evaluating its safety and efficacy in patients with advanced or metastatic solid tumors. According to information released by L&L Biopharma, LB-4330 has shown encouraging potential in an open-label, Phase Ib/II dose-escalation and expansion study. This study aims to explore the drug’s effects at various doses to identify an optimal dosing range that maximizes therapeutic benefit while minimizing adverse events. Although detailed clinical results have yet to be fully disclosed, preliminary data indicate that LB-4330 is well-tolerated and has demonstrated meaningful clinical activity in certain patient populations. Beyond its established indications in gastric cancer, pancreatic cancer, and ovarian cancer, researchers are investigating the potential of LB-4330 in other tumor types. Given the widespread expression of CLDN18.2 across multiple malignancies, LB-4330 could emerge as a broad-spectrum anti-cancer agent. Furthermore, as understanding of CLDN18.2 biology deepens and combination strategies with other therapies (such as chemotherapy, radiotherapy, or immunotherapy) are explored, the application prospects for LB-4330 appear increasingly expansive. Despite its promising profile, several challenges must be addressed before LB-4330 can be widely adopted. These include the need to accurately identify patients most likely to benefit from the therapy—often requiring precise measurement of CLDN18.2 expression—and the necessity for long-term safety evaluations. Additionally, further mechanistic studies, optimization of dosing strategies, and identification of ideal combination regimens with existing therapies will be critical to fully unlocking LB-4330’s therapeutic potential. CLDN18.2-Targeting ADCsSeveral antibody-drug conjugates (ADCs) have been developed to target Claudin 18.2 (CLDN18.2), including IBI-343, LM-302, SHR-A1904, ATG-022, Sonestatug vedotin, and SKB-315. These agents utilize a specific antibody to recognize and bind to CLDN18.2 antigens on the surface of cancer cells, delivering a potent cytotoxic payload intracellularly to induce tumor cell death. Developed by companies such as Innovent Biologics, LaNova Medicines, Hengrui Medicine, Antengene Corporation, and Kelun-Biotech, these ADCs span various stages of clinical development (from Phase II to Phase III) and show promise in treating gastric cancer, esophageal cancer, and other CLDN18.2-positive solid tumors. 1) IBI-343IBI-343 is an innovative ADC developed by Innovent Biologics. It combines a highly specific anti-CLDN18.2 antibody with a cytotoxic small-molecule drug. This design enables precise targeting of CLDN18.2-expressing tumor cells, facilitating selective delivery of the cytotoxic agent and minimizing damage to normal tissues, thus improving both safety and efficacy. In preclinical studies, a single administration of IBI-343 significantly inhibited tumor growth in xenograft models with low antigen expression, maintaining low tumor volumes for up to 21 days. This finding suggests that IBI-343 is not only effective against tumors with high CLDN18.2 expression but also shows robust activity in tumors with lower antigen levels. This bystander effect enhances IBI-343’s appeal as a cancer therapeutic, particularly in tumors with heterogeneous antigen expression within the tumor microenvironment. IBI-343 has been granted Breakthrough Therapy Designation by China’s National Medical Products Administration (NMPA) for two indications: (1) advanced gastric/gastroesophageal junction adenocarcinoma patients with positive CLDN18.2 expression who have received at least two prior systemic therapies, and (2) advanced pancreatic ductal adenocarcinoma patients with positive CLDN18.2 expression who have received at least one prior systemic therapy. This designation accelerates the development timeline and underscores the potential importance of IBI-343 as a novel treatment option, particularly for patients with difficult-to-treat cancers. 2) LM-302LM-302 is an antibody-drug conjugate (ADC) developed by Lanpu Biopharmaceuticals (also known as Lansion Biotechnology). This investigational therapy combines a highly specific anti-CLDN18.2 monoclonal antibody with a cytotoxic payload, monomethyl auristatin E (MMAE). The design enables the antibody to selectively bind to the CLDN18.2 antigen expressed on tumor cell surfaces and deliver the cytotoxic agent directly into cancer cells, thereby achieving targeted tumor cell killing. As of the latest updates, LM-302 has been granted three Orphan Drug Designations (ODDs) by the U.S. Food and Drug Administration (FDA) for the treatment of pancreatic cancer, gastric cancer, and gastroesophageal junction (GEJ) cancer. In China, LM-302 has advanced into Phase III clinical trials, indicating that the drug has demonstrated sufficient safety and preliminary efficacy in earlier studies and is now undergoing larger, more diverse patient evaluations to confirm its therapeutic potential. Moreover, LM-302 has been proposed for inclusion under China’s National Medical Products Administration (NMPA)/Center for Drug Evaluation (CDE) Breakthrough Therapy designation. The targeted indication is for patients with locally advanced or metastatic gastric or GEJ adenocarcinoma who are CLDN18.2-positive and have received at least two prior lines of systemic therapy. A Phase II clinical trial is also underway to evaluate the efficacy, safety, and tolerability of LM-302 in combination with toripalimab (an anti-PD-1 antibody) in patients with CLDN18.2-positive advanced gastrointestinal tumors. The primary endpoint of this study is to assess the efficacy of the LM-302 and toripalimab combination, with secondary objectives including safety, pharmacokinetics, immunogenicity, and the correlation between CLDN18.2/PD-L1 expression and antitumor activity. It is worth noting that Lanpu Biopharmaceuticals had previously entered into an exclusive licensing agreement with Turning Point Therapeutics, granting Turning Point rights to develop and commercialize LM-302 outside of Greater China and South Korea. However, following Bristol Myers Squibb’s acquisition of Turning Point, the licensing status of LM-302 has shifted, and the asset is now listed as "global" in ownership. 3) SHR-A1904SHR-A1904 is an ADC independently developed by Hengrui Medicine. It consists of a highly specific anti-CLDN18.2 antibody linked to a cytotoxic payload—a topoisomerase inhibitor (TOPOi). This design enables the ADC to selectively bind to CLDN18.2-expressing tumor cells and deliver its potent payload intracellularly, resulting in targeted cancer cell death. At the 2024 European Society for Medical Oncology (ESMO) Congress, early clinical data on SHR-A1904 were presented for the treatment of patients with CLDN18.2-positive gastric cancer and gastroesophageal junction adenocarcinoma (GC/GEJC). The results demonstrated manageable safety and promising antitumor activity, with an objective response rate (ORR) of 55.6% and a disease control rate (DCR) of 88.9%. Beyond gastric cancer, SHR-A1904 is also being investigated for other CLDN18.2-expressing solid tumors, highlighting its broad therapeutic potential. Notably, Hengrui Medicine entered into a collaboration agreement with Merck KGaA, Darmstadt, Germany, valued at up to €1.4 billion. Under this agreement, Merck has secured global exclusive development, manufacturing, and commercialization rights for SHR-A1904 outside of mainland China. This strategic partnership reflects strong international recognition of SHR-A1904's potential and positions it for global success. SHR-A1904 has been evaluated across multiple dose levels. The 6.0 mg/kg cohort demonstrated the best efficacy, achieving an ORR of 55.6% and a DCR of 88.9%. The safety profile was considered manageable, although some dose-limiting toxicities (DLTs) were observed at higher doses. With ongoing Phase III clinical trials, SHR-A1904 is poised to become a promising new treatment option for patients with CLDN18.2-positive cancers. Furthermore, through its international collaborations, SHR-A1904 is expected to benefit a broader patient population worldwide. ConclusionAs a member of the Claudin family, Claudin 18.2 (CLDN18.2) plays a vital role in maintaining tight junctions between epithelial and endothelial cells and is aberrantly overexpressed in various cancer types. This unique biological characteristic makes CLDN18.2 an ideal target for cancer therapy. Several CLDN18.2-targeted antibody-drug conjugates (ADCs)—including Zolbetuximab, IBI-343, LM-302, and SHR-A1904—have demonstrated significant antitumor activity with favorable safety profiles. Particularly, Zolbetuximab has achieved groundbreaking clinical success as the first approved therapy targeting CLDN18.2 for the treatment of gastric and gastroesophageal junction adenocarcinoma. Additionally, bispecific antibodies such as LB-4330, which enhance antitumor immune responses, are further expanding the therapeutic landscape of CLDN18.2 targeting. Globally, research on CLDN18.2-targeted therapies has become a major area of focus. More than 90 candidate therapies targeting CLDN18.2—including monoclonal antibodies, bispecific antibodies, CAR-T cells, and ADCs—are currently under development. The success of programs such as IBI-343 not only highlights the innovation capacity of Chinese biopharmaceutical companies but also provides valuable models for future drug development. As clinical trials progress and technologies advance, CLDN18.2-targeted therapies are expected to offer new hope for a broader range of cancer patients, driving forward the era of personalized medicine and precision oncology. These developments mark a deeper understanding of cancer biology and herald the arrival of more CLDN18.2-based therapies, ultimately benefiting patients worldwide. How to obtain the latest research advancements in the field of biopharmaceuticals? In the Synapse database, you can keep abreast of the latest research and development advances in drugs, targets, indications, organizations, etc., anywhere and anytime, on a daily or weekly basis. Click on the image below to embark on a brand new journey of drug discovery! Reference 1. Cao W, Xing H, Li Y, Tian W, Song Y, Jiang Z, Yu J. Claudin18.2 is a novel molecular biomarker for tumor-targeted immunotherapy. Biomark Res. 2022 May 31;10(1):38. doi: 10.1186/s40364-022-00385-1. PMID: 35642043; PMCID: PMC9153115.2. Kubota Y, Shitara K. Zolbetuximab for Claudin18.2-positive gastric or gastroesophageal junction cancer. Ther Adv Med Oncol. 2024 Jan 3;16:17588359231217967. doi: 10.1177/17588359231217967. PMID: 38188462; PMCID: PMC10768589.3. van der Leun AM, Thommen DS, Schumacher TN. CD8+ T cell states in human cancer: insights from single-cell analysis. Nat Rev Cancer. 2020 Apr;20(4):218-232. doi: 10.1038/s41568-019-0235-4. Epub 2020 Feb 5. PMID: 32024970; PMCID: PMC7115982.

KEYNOTE-689 marks the first positive trial in more than two decades for patients with resected locally advanced head and neck squamous cell carcinoma (LA-HNSCC) Results to be presented at American Association for Cancer Research (AACR) Annual Meeting 2025 during a Plenary Session and included in official meeting press program RAHWAY, NJ, USA I April 27, 2025 I Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced results from the Phase 3 KEYNOTE-689 trial evaluating KEYTRUDA ® (pembrolizumab), Merck’s anti-PD-1 therapy, as a perioperative treatment regimen for patients with stage III or IVA, resected, locally advanced head and neck squamous cell carcinoma (LA-HNSCC). Results at the first interim analysis of the trial showed KEYTRUDA significantly improved event-free survival (EFS) as part of a perioperative treatment regimen with adjuvant standard of care (SOC) radiotherapy with or without cisplatin compared to adjuvant standard of care (SOC) radiotherapy with or without cisplatin alone in patients with resectable LA-HNSCC. These data are being presented for the first time today during a Plenary Session at the American Association for Cancer Research (AACR) Annual Meeting 2025 (Abstract #CT001) and were selected for the AACR press program. After a median follow-up of 38.3 months (range, 9.0-66.5), treatment with KEYTRUDA before surgery (neoadjuvant), then continued in combination with standard of care radiotherapy (with or without cisplatin) after surgery followed by KEYTRUDA alone (adjuvant), reduced the risk of EFS events by 34% (HR=0.66 [95% CI, 0.49-0.88]; p=.0022) in the combined positive score (CPS) ≥10 population, by 30% (HR=0.70 [95% CI, 0.55-0.89; p=.0014) in the CPS ≥1 population and by 27% (HR=0.73 [95% CI 0.58-0.92]; p=.0041) in the intent-to-treat (ITT) population, compared to adjuvant radiotherapy (with or without cisplatin) alone in the ITT population. Among the CPS ≥10 population, median EFS was 59.7 months in the KEYTRUDA plus SOC group (95% CI, 41.1-not reached) versus 26.9 months (95% CI, 18.3-51.5) in the SOC group. Among the CPS ≥1 population, median EFS was 59.7 months (95% CI, 37.9-not reached) in the KEYTRUDA plus SOC group versus 29.6 months (95% CI, 19.5-41.9) in the SOC group. In the ITT population, median EFS was 51.8 months (95% CI, 37.5-not reached) in the KEYTRUDA plus SOC group versus 30.4 months (95% CI, 21.8-50.1) in the SOC group. The safety profile of KEYTRUDA was consistent with that observed in previously reported studies; no new safety signals were identified. “As the first positive trial in over two decades for patients with resectable, locally advanced head and neck squamous cell carcinoma, the presentation of these landmark results marks an important moment for these patients and those who care for them,” said Dr. Ravindra Uppaluri, the study’s co-principal investigator, director of Head and Neck Surgical Oncology, Brigham and Women’s Hospital and Dana-Farber Cancer Institute. “KEYNOTE-689 represents a meaningful development with a potential to provide an option that helps certain patients with LA-HNSCC reduce the risk of recurrence and disease progression earlier in their treatment journey.” “The addition of immunotherapy using KEYTRUDA to standard of care surgery and adjuvant (chemo)radiotherapy resulted in a significant reduction in the risk of event-free survival events by 27%, compared with standard of care therapy alone,” said study co-principal investigator Dr. Douglas Adkins, Professor, Division of Oncology, Washington University School of Medicine in St. Louis. “These results are notable as they mark the first time an anti-PD-1 therapy has demonstrated a statistically significant and clinically meaningful improvement in event-free survival in the neoadjuvant and adjuvant setting in earlier stages of head and neck squamous cell carcinoma.” The study also showed a statistically significant improvement in major pathological response (mPR) rate, a key secondary endpoint, in patients with CPS ≥10 (difference in mPR rates: 13.7% [95% CI, 9.7-18.7]; p<0.00001), CPS ≥1 (9.8% [95% CI, 7.0-13.3]; p<0.00001) and in the ITT population (9.3% [95% CI, 6.7–12.8, P<.00001), compared to adjuvant radiotherapy alone. A trend toward improvement in overall survival (OS), another key secondary endpoint, was observed in patients with CPS ≥10 (HR=0.72 [95% CI, 0.52-0.98])at the time of this interim analysis for the KEYTRUDA plus standard of care regimen versus standard of care alone. The OS results did not reach statistical significance at the time of this interim analysis. Due to the statistical testing hierarchy, formal testing was not performed in the CPS ≥1 and ITT populations. OS will be evaluated at the next interim analysis. “As the 12 th positive pivotal trial for a KEYTRUDA-based regimen in earlier-stage cancers, the results from KEYNOTE-689 are a testament to our commitment to address an unmet need in this important area of research,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “These compelling results illustrate the potential of this regimen to change the landscape of care for certain patients facing this challenging disease. We are working with the FDA and other global authorities to bring this new option to patients as quickly as possible.” A supplemental Biologics License Application (sBLA) for KEYTRUDA based on data from KEYNOTE-689 is under priority review with the U.S. Food and Drug Administration (FDA), with a Prescription Drug User Fee Act (PDUFA), or target action, date of June 23, 2025. KEYTRUDA is currently approved as monotherapy and in combination regimens for appropriate patients with metastatic or unresectable, recurrent HNSCC in the U.S., Europe, China, Japan and other countries around the world. For more information, please see the “Selected KEYTRUDA ® (pembrolizumab) Indications in the U.S.” section below. Study design and additional data from KEYNOTE-689 KEYNOTE-689 is a randomized, active-controlled, open-label Phase 3 trial (ClinicalTrials.gov, NCT03765918 ) evaluating KEYTRUDA as neoadjuvant treatment and KEYTRUDA in combination with standard of care radiotherapy (with or without cisplatin) as adjuvant treatment in treatment-naïve patients with newly diagnosed, stage III or IVA resectable, locally advanced head and neck squamous cell carcinoma (LA-HNSCC). Efficacy outcomes are classified by programmed cell death ligand 1 (PD-L1) combined positive score (CPS) status. The primary endpoint is EFS, which is defined as the time from randomization to the first occurrence of radiographic disease progression; local or distant progression or recurrence; or death due to any cause. The secondary endpoints include OS, mPR, pathological complete response and safety. The study enrolled 714 patients who were randomized 1:1 to receive: The safety profile of KEYTRUDA was consistent with that observed in previously reported studies. Grade ≥3 treatment-related adverse events (TRAEs) occurred in 44.6% of patients receiving KEYTRUDA plus standard of care radiotherapy versus 42.9% of patients receiving standard of care radiotherapy alone. TRAEs led to death in 1.1% of patients receiving the KEYTRUDA regimen (n=4) and 0.3% of patients receiving standard of care radiotherapy (n=1). No new safety concerns were identified. Immune-mediated adverse events (AEs) of any grade occurred in 43.2% of patients receiving the KEYTRUDA regimen, most commonly hypothyroidism (24.7%). About head and neck cancer Head and neck cancer describes a number of different tumors that develop in or around the throat, larynx, nose, sinuses and mouth. Most head and neck cancers are squamous cell carcinomas that begin in the flat, squamous cells that make up the thin surface layer of the structures in the head and neck. Locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is cancer that has grown outside the original location, but has not yet spread to distant parts of the body. There are several factors that greatly increase the risk of developing head and neck cancer, including tobacco and alcohol use and human papillomavirus (HPV). It is estimated there were more than 947,200 new cases of head and neck cancer diagnosed and over 482,400 deaths from the disease in 2022 globally. In the U.S., it is estimated there will be approximately 72,680 new cases of head and neck cancer diagnosed and more than 16,680 deaths from the disease in 2025. About Merck’s early-stage cancer clinical program Finding cancer at an earlier stage may give patients a greater chance of long-term survival. Many cancers are considered most treatable and potentially curable in their earliest stage of disease. Building on the strong understanding of the role of KEYTRUDA in later-stage cancers, Merck is evaluating our portfolio of medicines and pipeline candidates in earlier disease states, with more than 30 ongoing registrational studies across multiple types of cancer. About KEYTRUDA ® (pembrolizumab) injection, 100 mg KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD- L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells. Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient’s likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers. Selected KEYTRUDA ® (pembrolizumab) Indications in the U.S. Head and Neck Squamous Cell Cancer KEYTRUDA, in combination with platinum and fluorouracil (FU), is indicated for the first-line treatment of patients with metastatic or with unresectable, recurrent head and neck squamous cell carcinoma (HNSCC). KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with metastatic or with unresectable, recurrent HNSCC whose tumors express PD-L1 [Combined Positive Score (CPS) ≥1] as determined by an FDA-approved test. KEYTRUDA, as a single agent, is indicated for the treatment of patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy. Melanoma KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic melanoma. KEYTRUDA is indicated for the adjuvant treatment of adult and pediatric (12 years and older) patients with Stage IIB, IIC, or III melanoma following complete resection. Non-Small Cell Lung Cancer KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations. KEYTRUDA, in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, is indicated for the first-line treatment of patients with metastatic squamous NSCLC. KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with NSCLC expressing PD-L1 [Tumor Proportion Score (TPS) ≥1%] as determined by an FDA-approved test, with no EGFR or ALK genomic tumor aberrations, and is: KEYTRUDA, as a single agent, is indicated for the treatment of patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-approved test, with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving KEYTRUDA. KEYTRUDA is indicated for the treatment of patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery. KEYTRUDA, as a single agent, is indicated as adjuvant treatment following resection and platinum-based chemotherapy for adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC. Malignant Pleural Mesothelioma KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of adult patients with unresectable advanced or metastatic malignant pleural mesothelioma (MPM). Classical Hodgkin Lymphoma KEYTRUDA is indicated for the treatment of adult patients with relapsed or refractory classical Hodgkin lymphoma (cHL). KEYTRUDA is indicated for the treatment of pediatric patients with refractory cHL, or cHL that has relapsed after 2 or more lines of therapy. Primary Mediastinal Large B-Cell Lymphoma KEYTRUDA is indicated for the treatment of adult and pediatric patients with refractory primary mediastinal large B-cell lymphoma (PMBCL), or who have relapsed after 2 or more prior lines of therapy. KEYTRUDA is not recommended for treatment of patients with PMBCL who require urgent cytoreductive therapy. Urothelial Cancer KEYTRUDA, in combination with enfortumab vedotin, is indicated for the treatment of adult patients with locally advanced or metastatic urothelial cancer. KEYTRUDA, as a single agent, is indicated for the treatment of patients with locally advanced or metastatic urothelial carcinoma: KEYTRUDA, as a single agent, is indicated for the treatment of patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors who are ineligible for or have elected not to undergo cystectomy. Microsatellite Instability-High or Mismatch Repair Deficient Cancer KEYTRUDA is indicated for the treatment of adult and pediatric patients with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. Microsatellite Instability-High or Mismatch Repair Deficient Colorectal Cancer KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-approved test. Gastric Cancer KEYTRUDA, in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test. This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval of this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. KEYTRUDA, in combination with fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma. Esophageal Cancer KEYTRUDA is indicated for the treatment of patients with locally advanced or metastatic esophageal or gastroesophageal junction (GEJ) (tumors with epicenter 1 to 5 centimeters above the GEJ) carcinoma that is not amenable to surgical resection or definitive chemoradiation either: Cervical Cancer KEYTRUDA, in combination with chemoradiotherapy (CRT), is indicated for the treatment of patients with FIGO 2014 Stage III-IVA cervical cancer. KEYTRUDA, in combination with chemotherapy, with or without bevacizumab, is indicated for the treatment of patients with persistent, recurrent, or metastatic cervical cancer whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test. KEYTRUDA, as a single agent, is indicated for the treatment of patients with recurrent or metastatic cervical cancer with disease progression on or after chemotherapy whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test. Hepatocellular Carcinoma KEYTRUDA is indicated for the treatment of patients with hepatocellular carcinoma (HCC) secondary to hepatitis B who have received prior systemic therapy other than a PD-1/PD-L1-containing regimen. Biliary Tract Cancer KEYTRUDA, in combination with gemcitabine and cisplatin, is indicated for the treatment of patients with locally advanced unresectable or metastatic biliary tract cancer (BTC). Merkel Cell Carcinoma KEYTRUDA is indicated for the treatment of adult and pediatric patients with recurrent locally advanced or metastatic Merkel cell carcinoma (MCC). Renal Cell Carcinoma KEYTRUDA, in combination with axitinib, is indicated for the first-line treatment of adult patients with advanced renal cell carcinoma (RCC). KEYTRUDA is indicated for the adjuvant treatment of patients with RCC at intermediate-high or high risk of recurrence following nephrectomy, or following nephrectomy and resection of metastatic lesions. Endometrial Carcinoma KEYTRUDA, in combination with carboplatin and paclitaxel, followed by KEYTRUDA as a single agent, is indicated for the treatment of adult patients with primary advanced or recurrent endometrial carcinoma. KEYTRUDA, as a single agent, is indicated for the treatment of adult patients with advanced endometrial carcinoma that is MSI-H or dMMR, as determined by an FDA-approved test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation. Tumor Mutational Burden-High Cancer KEYTRUDA is indicated for the treatment of adult and pediatric patients with unresectable or metastatic tumor mutational burden-high (TMB-H) [≥10 mutations/megabase (mut/Mb)] solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. The safety and effectiveness of KEYTRUDA in pediatric patients with TMB-H central nervous system cancers have not been established. Cutaneous Squamous Cell Carcinoma KEYTRUDA is indicated for the treatment of patients with recurrent or metastatic cutaneous squamous cell carcinoma (cSCC) or locally advanced cSCC that is not curable by surgery or radiation. Triple-Negative Breast Cancer KEYTRUDA is indicated for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery. KEYTRUDA, in combination with chemotherapy, is indicated for the treatment of patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS ≥10) as determined by an FDA-approved test. Merck’s focus on cancer Every day, we follow the science as we work to discover innovations that can help patients, no matter what stage of cancer they have. As a leading oncology company, we are pursuing research where scientific opportunity and medical need converge, underpinned by our diverse pipeline of more than 25 novel mechanisms. With one of the largest clinical development programs across more than 30 tumor types, we strive to advance breakthrough science that will shape the future of oncology. By addressing barriers to clinical trial participation, screening and treatment, we work with urgency to reduce disparities and help ensure patients have access to high-quality cancer care. Our unwavering commitment is what will bring us closer to our goal of bringing life to more patients with cancer. For more information, visit http://www.merck.com/research/oncology . About Merck At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.merck.com and connect with us on X (formerly Twitter) , Facebook , Instagram , YouTube and LinkedIn . SOURCE: Merck

DUBLIN , April 25, 2025 /PRNewswire/ -- Jazz Pharmaceuticals plc (Nasdaq: JAZZ) today announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive opinion recommending the conditional marketing authorization of zanidatamab, an investigational dual human epidermal growth factor receptor 2 (HER2)-targeted bispecific antibody, as monotherapy for the treatment of adults with unresectable locally advanced or metastatic HER2-positive (IHC 3+)† biliary tract cancer (BTC) previously treated with at least one prior line of systemic therapy.1 "This positive CHMP opinion is a welcome step for physicians and patients in Europe who face a critical unmet need in HER2-positive biliary tract cancers, a rare and aggressive group of cancers with poor prognosis and limited treatment options," said Robert Iannone , MD., M.S.C.E., executive vice president, global head of research and development, and chief medical officer of Jazz Pharmaceuticals . "If approved, zanidatamab would be the first HER2-targeted therapy licensed for this difficult-to-treat cancer in the EU, marking an important milestone in addressing this unmet need. We look forward to the European Commission's decision and the opportunity to provide a new treatment option for patients." The CHMP recommendation is based on data from the Phase 2b HERIZON-BTC-01 trial, which evaluated zanidatamab in previously treated, inoperable, and advanced or metastatic HER2-positive BTC.2,3 While biliary tract cancers (BTCs), which include gallbladder cancer (GBC) and cholangiocarcinoma (CCA),4 account for less than 1% of all human cancers,5 CCA is the second most common primary liver cancer after hepatocellular carcinoma (HCC).5 It comprises approximately 10–15% of all primary liver cancers,4,5 and its global mortality rate has risen in recent decades.5 Most BTC cases are diagnosed at an advanced stage due to the vague or nonspecific nature of early disease symptoms,6 making curative surgery an option for only a minority of patients.5,7,8 Although chemotherapy and, more recently, immunotherapy-based combinations are used in the first-line setting, disease progression is common, and second-line treatment options are, in the absence of molecular analysis, largely limited to chemotherapy.5,7,9 HER2 overexpression or amplification has been identified as a distinct molecular subtype of BTC10,11 and is associated with a worse prognosis compared to HER2-negative BTC.12 Yet, no HER2-targeted therapies are currently approved for this indication in the European Union (EU). The CHMP's recommendation will now be reviewed by the European Commission which has the authority to approve medicines in all EU Member States, Iceland , Norway , and Liechtenstein , and is expected to make a final decision. About Zanidatamab Zanidatamab is a dual HER2-targeted bispecific antibody that simultaneously binds extracellular domains 2 and 4 on separate HER2 monomers (binding in trans). Binding of zanidatamab with HER2 results in internalization leading to a reduction of the receptor on the 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 tumor cell death.13 On November 20, 2024 , in the United States, the U.S. Food and Drug Administration (FDA) granted accelerated approval of zanidatamab-hrii (Ziihera®) 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.14 This accelerated approval was granted based on objective response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the ongoing Phase 3 HERIZON-BTC-302 confirmatory trial.14 Zanidatamab is also being investigated in multiple other clinical trials as a targeted treatment option for patients with solid tumors that express HER2. Zanidatamab is being developed by Jazz and BeiGene, Ltd. (BeiGene) under license agreements from Zymeworks, which first developed the molecule. Jazz has rights to commercialize zanidatamab in the U.S. , Europe , Japan and all other territories except for those Asia/Pacific territories that Zymeworks previously licensed to BeiGene, Ltd. [which are Asia (excluding Japan ), Australia and New Zealand ]. The FDA granted Breakthrough Therapy designation for zanidatamab development in patients with previously treated HER2 gene-amplified BTC, and two Fast Track designations for zanidatamab: one as a single agent for refractory BTC and one in combination with standard-of-care chemotherapy for 1L gastroesophageal adenocarcinoma (GEA). Additionally, zanidatamab has received Orphan Drug designations from FDA for the treatment of BTC and GEA, as well as Orphan Drug designation from the European Medicines Agency for the treatment of BTC and gastric cancer. About Biliary Tract Cancer Biliary tract cancers (BTC), including gallbladder cancer and intrahepatic and extrahepatic cholangiocarcinoma, account for <1% of all adult cancers worldwide and are often associated with a poor prognosis.5,7 Approximately 26% of patients with BTC are HER2-positive.10 The human epidermal growth factor receptor 2 (HER2) is a well-validated target for antitumor therapy in other cancers.7,15 Across the U.S., Europe, and Japan, approximately 12,000 people are diagnosed with HER2+ BTC annually.16 Most patients (>65%) are diagnosed with tumors that cannot be removed surgically.7 About Jazz Pharmaceuticals plc Jazz Pharmaceuticals plc (Nasdaq: JAZZ) is a global biopharma company whose purpose is to innovate to transform the lives of patients and their families. We are dedicated to developing potentially life-changing medicines for people with serious diseases — often with limited or no therapeutic options. We have a diverse portfolio of marketed medicines, including leading therapies for sleep disorders and epilepsy, and a growing portfolio of cancer treatments. Our patient-focused and science-driven approach powers pioneering research and development advancements across our robust pipeline of innovative therapeutics in oncology and neuroscience. Jazz is headquartered in Dublin, Ireland with research and development laboratories, manufacturing facilities and employees in multiple countries committed to serving patients worldwide. Please visit www.jazzpharmaceuticals.com for more information. Jazz Pharmaceuticals plc Caution Concerning Forward-Looking StatementsThis press release contains forward-looking statements, including, but not limited to, statements related to the European Commission's potential approval of zanidatamab for the treatment of adults with BTC in the EU and other statements that are not historical facts. These forward-looking statements are based on Jazz Pharmaceuticals' current plans, objectives, estimates, expectations and intentions and inherently involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks and uncertainties associated with the successful completion of regulatory activities and uncertain regulatory approval, and other risks and uncertainties affecting Jazz Pharmaceuticals and its development programs, including those described from time to time under the caption "Risk Factors" and elsewhere in Jazz Pharmaceuticals plc's Securities and Exchange Commission filings and reports (Commission File No. 001-33500), including Jazz Pharmaceuticals' Annual Report on Form 10-K for the year ended December 31, 2024 , and future filings and reports by Jazz Pharmaceuticals . Other risks and uncertainties of which Jazz Pharmaceuticals is not currently aware may also affect Jazz Pharmaceuticals' forward-looking statements and may cause actual results and the timing of events to differ materially from those anticipated. The forward-looking statements herein are made only as of the date hereof or as of the dates indicated in the forward-looking statements, even if they are subsequently made available by Jazz Pharmaceuticals on its website or otherwise. Jazz Pharmaceuticals undertakes no obligation to update or supplement any forward-looking statements to reflect actual results, new information, future events, changes in its expectations or other circumstances that exist after the date as of which the forward-looking statements were made. Media Contact: Kristin Bhavnani Head of Global Corporate Communications Jazz Pharmaceuticals plc CorporateAffairsMediaInfo@jazzpharma.com Ireland +353 1 637 2141 U.S. +1 215 867 4948 Investors: Jeff Macdonald Executive Director, Investor Relations Jazz Pharmaceuticals plc investorinfo@jazzpharma.com Ireland +353 1 634 3211 U.S. +1 650 496 2717 † IHC3+ stands for ImmunoHistoChemistry 3+ and refers to the highest level of HER2 protein overexpression in cancer cells References _______________________ 1 Meeting highlights from the Committee for Medicinal Products for Human Use (CHMP) 22-25 April 2025 | European Medicines Agency (EMA). European Medicines Agency (EMA). Published April 25, 2025 . Accessed April 25, 2025 . https://www.ema.europa.eu/en/news/meeting-highlights-committee-medicinal-products-human-use-chmp-22-25-april-20252 Pant, S et al. Zanidatamab in Previously Treated HER2-Positive Biliary Tract Cancer: Overall Survival and Longer Follow-Up From the Phase 2b HERIZON-BTC-01 Study. J Clin Oncol. 2024; 42(16_suppl). Abstract 4091.3 Harding J, Fan J, Oh D-Y, et al. Zanidatamab for HER2-amplified, unresectable, locally advanced or metastatic biliary tract cancer (HERIZON-BTC-01): a multicentre, single-arm, phase 2b study. Lancet Oncol. 2023;24(7):772-82. doi:10.1016/S1470-2045(23)00242-5.4 Mirallas O, López-Valbuena D, García-Illescas D , et al. Advances in the systemic treatment of therapeutic approaches in biliary tract cancer. ESMO Open. 2022;7(3):100503. doi:10.1016/j.esmoop.2022.100503.5 Vogel A, Bridgewater J, Edeline J, et al. Biliary tract cancer: ESMO Clinical Practice Guideline for diagnosis, treatment, and follow-up. Ann Oncol. 2023;34(2):127-40. doi:10.1016/j.annonc.2022.10.506.6 Rimassa, L., Khan, S., Koerkamp, B. G., Roessler, S.,et al. Mapping the landscape of biliary tract cancer in Europe : challenges and controversies. The Lancet Regional Health–Europe. 2025; 50, 101171. doi.org/10.1016/j.lanepe.2024.1011717 Chakrabarti, S., Kamgar, M., Mahipal, A. Targeted therapies in advanced biliary tract cancer: an evolving paradigm. Cancers. 2020;12(8), 2039. doi.org/10.3390/cancers120820398 Valle JW, Kelley RK, et al. Biliary tract cancer. Lancet . 2021;397(10272):428-44. doi:10.1016/S0140-6736(21)00153-7.9 Lamarca, A., Hubner, R. A., Ryder, W. D.,et al. Second-line chemotherapy in advanced biliary cancer: a systematic review. Annals of Oncology. 2025; 25(12), 2328-2338. doi.org/10.1093/annonc/mdu16210 Galdy S, Lamarca A, et al. HER2/HER3 pathway in biliary tract malignancies; systematic review and meta-analysis: a potential therapeutic target? Cancer Metastas Rev. 2017; doi: 10.1007/s10555-016-9645-x11 Hechtman, J. F., Liu, W., Sadowska, J.,et al. Sequencing of 279 cancer genes in ampullary carcinoma reveals trends relating to histologic subtypes and frequent amplification and overexpression of ERBB2 (HER2). Modern Pathology. 2015;28(8), 1123-1129. doi: 10.1038/modpathol.2015.5712 Vivaldi, C. HER2 overexpression as a poor prognostic determinant in resected biliary tract cancer. Oncologist. 2020;25(10):886-893. doi:10.1634/theoncologist.2019-0922.13 Weisser NE, Sanches M, Escobar-Cabrera E et al. An anti-HER2 biparatopic antibody that induces unique HER2 clustering and complement-dependent cytotoxicity. Nature Communications . 2023 Mar 13;14(1):1394. doi: 10.1038/s41467-023-37029-314 U.S. Food and Drug Administration . Ziihera® (zanidatamab-hrii) prescribing information. Accessdata.fda.gov. Updated November 2024 . Accessed April 22, 2025 . https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/761416s000lbl.pdf15 Meric-Bernstam, F., Beeram, et al. Zanidatamab, a novel bispecific antibody, for the treatment of locally advanced or metastatic HER2-expressing or HER2-amplified cancers: a phase 1, dose-escalation and expansion study. The Lancet Oncology. 2022; doi: 10.1016/S1470-2045(22)00621-016 Jazz Pharmaceuticals, Inc , Data on file. View original content to download multimedia:https://www.prnewswire.com/news-releases/jazz-pharmaceuticals-receives-chmp-positive-opinion-for-zanidatamab-for-the-treatment-of-advanced-her2-positive-biliary-tract-cancer-302438480.html SOURCE Jazz Pharmaceuticals plc