P1, N=0, Withdrawn, SparX Biotech(Jiangsu) Co., Ltd. | N=27 --> 0 | Trial completion date: Aug 2023 --> Aug 2024 | Not yet recruiting --> Withdrawn | Trial primary completion date: Mar 2023 --> Apr 2024

P1/2, N=320, Recruiting, Suzhou Transcenta Therapeutics Co., Ltd. | Trial completion date: Nov 2024 --> May 2025 | Trial primary completion date: Aug 2024 --> Feb 2025

In PD-L1low HER-2 negative GEAC, the benefit of first-line ICI is modest, yet significant. Further translational work is warranted to better select patients who could benefit from immunotherapy in this setting. Meanwhile, alternative therapeutic options such as zolbetuximab in Claudin18.2-positive disease must be taken into account.

"Roche...announced today that the VENTANA CLDN18 (43-14A) RxDx Assay is the first U.S. Food and Drug Administration (FDA) approved immunohistochemistry (IHC) companion diagnostic for determining CLDN18 protein expression in tumours of patients with gastric or gastroesophageal junction (GEJ) adenocarcinoma. These patients now may be eligible for treatment with Astellas' targeted therapy VYLOY (zolbetuximab)....VYLOY is the first FDA-approved treatment specifically targeting HER2-negative locally advanced unresectable or metastatic gastric or GEJ cancer patients whose tumours are CLDN18.2-positive."

P1/2, N=150, Active, not recruiting, Suzhou Transcenta Therapeutics Co., Ltd. | Recruiting --> Active, not recruiting | Trial primary completion date: Jun 2024 --> Nov 2024

P1, N=12, Completed, Innovent Biologics (Suzhou) Co. Ltd. | Recruiting --> Completed | Phase classification: P1a/1b --> P1 | N=48 --> 12

CLDN18.2-TAC T cells effectively eradicated established tumor xenografts in mice in the absence of observed off-target or on-target/off-tumor effects, elicited durable efficacy in recursive killing and tumor rechallenge experiments, and remained unreactive in coculture with human cells representing vital organs. Thus, the data demonstrate that CLDN18.2-TAC T cells can induce a specific and long-lasting anti-tumor response in various CLDN18.2-positive solid tumor models without notable TAC-dependent toxicities, supporting the clinical development of TAC01-CLDN18.2.

"Roche...announced today that the VENTANA CLDN18 (43-14A) RxDx Assay is the first immunohistochemistry (IHC) companion diagnostic test to receive CE Mark approval for determining CLDN18 protein expression in tumours of patients with gastric or gastroesophageal junction (GEJ) adenocarcinoma. These patients now may be eligible for treatment with Astellas’ targeted therapy VYLOY (zolbetuximab)...The new VENTANA CLDN18 (43-14A) RxDx Assay can help determine CLDN18.2 status and inform clinicians about the likelihood of patients benefiting from CLDN18.2 targeted therapy...The approval of the VENTANA CLDN18 (43-14A) RxDx Assay is based on the results of the SPOTLIGHT and GLOW clinical studies where it was used as the enrollment assay to identify patients whose tumours were CLDN18.2 positive."

A significant portion of surgically resected PCC specimens showed CLDN18.2 positivity. Additionally, since the expression level of CLDN18.2 gradually decreases with increased paraffin block storage time, reflex testing can be considered at the time of the cancer diagnosis.

The effect of antiemetics (dexamethasone, ondansetron, fosaprepitant, and olanzapine) on emesis induced by zolbetuximab was investigated. Fosaprepitant showed suppressive effects on emesis, and use of dexamethasone or concomitant use of fosaprepitant with other antiemetics tended to alleviate gastric tissue damage. The onset of emesis in humans receiving zolbetuximab may be associated with damage in the gastric mucosa, and antiemetics may mitigate gastrointestinal adverse events.

P1, N=305, Recruiting, Astellas Pharma Global Development, Inc. | Trial completion date: Dec 2026 --> Apr 2027 | Trial primary completion date: Jun 2026 --> Oct 2026

P2, N=393, Active, not recruiting, Astellas Pharma Global Development, Inc. | Trial completion date: Apr 2025 --> Aug 2026 | Trial primary completion date: Sep 2024 --> Aug 2026

P1, N=34, Completed, Zai Biopharmaceutical (Suzhou) Co., Ltd. | Phase classification: P1/2 --> P1

P1, N=12, Recruiting, Astellas Pharma Global Development, Inc. | Not yet recruiting --> Recruiting

At the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting, the final results of the phase 3 SPOTLIGHT trial were presented, demonstrating a significant survival benefit from the addition of the CLDN18.2-specific antibody zolbetuximab to chemotherapy in the first-line treatment of advanced gastroesophageal adenocarcinomas with ≥ 75% CLDN18.2 expression...In addition, several early-phase trials presented at ASCO 2024 investigate other CLDN18.2-targeting approaches in CLDN18.2-positive refractory advanced solid tumors, including the CLDN18.2-targeting antibody-drug conjugates LM-302 and IBI343, the bispecific anti-CLDN18.2/CD3 antibody IBI38, and the chimeric antigen receptor T cell therapy satricabtagene autoleucel. These novel approaches could potentially expand the benefit of CLDN18.2-targeting therapies to a broader range of tumor types and to tumors expressing lower levels of CLDN18.2.

In CD-associated small bowel adenocarcinomas, Cadherin 17 expression was frequently retained and Claudin 18 was frequently co-expressed. Claudin 18 had a positive correlation with the expression of gastric mucins. These results suggest that CD-associated small bowel adenocarcinomas may be candidates for Cadherin 17- and Claudin 18-targeted immunotherapies.

Patients in SPOTLIGHT and GLOW maintained measured HRQoL relative to baseline when treated with first-line zolbetuximab added to chemotherapy. Zolbetuximab plus chemotherapy improved PFS and OS without negatively affecting HRQoL in key PRO domains compared with placebo plus chemotherapy.

P1, N=305, Recruiting, Astellas Pharma Global Development, Inc. | Trial completion date: Jun 2026 --> Dec 2026

Several pre-analytical and analytical variables may interfere with adequate CLDN18.2 staining interpretation, thus this article provides practical guidance on CLDN18.2 testing and scoring in gastric/gastroesophageal junction adenocarcinomas in order to identify patients who may respond to targeted therapy with monoclonal antibodies directed against CLDN18.2. Based on available data, moderate to strong (2+/3+) membrane staining in ≥75% of adenocarcinoma cells is the proposed cut-off for clinical use of the monoclonal antibody anti-CLDN18.2 (zolbetuximab).

Importantly, both CLDN18.2 expression and the number of tumor-infiltrating NK cells were significantly higher in EBV-associated GC compared to other molecular subtypes. Our findings support the effectiveness of zolbetuximab in CLDN18.2-positive GC, and offer a novel insight into the treatment of this cancer type, highlighting its potential effectiveness for CLDN18.2-positive/EBV-associated GC.

P1, N=30, Recruiting, Zhejiang Provincial People's Hospital | Not yet recruiting --> Recruiting

P1, N=94, Recruiting, Zhejiang Doer Biologics Co., Ltd. | Trial primary completion date: Jun 2024 --> Jun 2025

Updated data indicate that the combination of TST001 plus nivolumab and CAPOX as the 1L treatment for patients with G/GEJ cancer is safe and well tolerated with very encouraging anti-tumor activities, especially for patients with high/medium CLDN18.2 expression when cross comparing to historical data.

P1, N=168, Recruiting, I-Mab Biopharma US Limited | N=102 --> 168 | Trial completion date: Dec 2024 --> Dec 2025 | Trial primary completion date: Sep 2024 --> Dec 2024

P1/2, N=194, Recruiting, L & L biopharma Co., Ltd., Shanghai China | Not yet recruiting --> Recruiting

Zolbetuximab is also undergoing regulatory review for HER2-, CLDN18.2+ advanced gastric or GEJ adenocarcinoma in the USA, the EU, China, Australia and several other countries. This article summarizes the milestones in the development of zolbetuximab leading to this first approval for the treatment of patients with CLDN18.2+ gastrointestinal malignancies.

CLDN18.2 was a highly prevalent biomarker in patients with HER2-negative, LA unresectable or mG/GEJ adenocarcinoma. CLDN18.2 positivity remained relatively stable over time in many patients. Biomarker testing for CLDN18.2 should be considered in standard clinical practice in these patients.

Due to the excellent targeting ability of zolbetuximab for CLDN18.2, [125I]I-zolbetuximab exhibits strong specific binding and retention with cells and tumors highly expressing CLDN18.2. However, the balance between mAb's longer cycle time in vivo and targeting binding and retention ability should be intensively considered for using this kind of radiopharmaceutical in the diagnosis and treatment of CLDN18.2-positive gastric cancer.

Further studies are needed to determine its role within current gastric cancer treatment sequencing, including HER2-targeted therapies and immunotherapies. Management strategies will also be needed to better mitigate zolbetuximab-related treatment side effects, including gastrointestinal (GI) toxicities.

Significant improvement in survival could be demonstrated by adding Zolbetuximab to known chemotherapy regimes in patients with gastro-esophageal junction adenocarcinoma with at least 75 % CLDN18.2 positive cancer cells. Our findings demonstrate, that 30.4 % of the included patients with PDAC would potentially be eligible for therapy with Zolbetuximab in a real-world patient cohort. Results of trials targeting Claudin 18.2 are pending in patients with PDAC.

P1, N=40, Recruiting, Second Affiliated Hospital of Guangzhou Medical University | Trial primary completion date: Dec 2025 --> Dec 2029

P1/2, N=194, Not yet recruiting, L & L biopharma Co., Ltd., Shanghai China

P1, N=30, Not yet recruiting, Zhejiang Provincial People's Hospital

Aim: To estimate the cost-effectiveness of zolbetuximab plus capecitabine/oxaliplatin (CAPOX) in CLDN18.2-positive, HER2-negative, mG/GEJ adenocarcinoma from the perspective of Chinese payers. Sensitivity analysis shows that the model was generally robust. Zolbetuximab plus CAPOX would not be a cost-effective first-line treatment regimen in CLDN18.2-positive, HER2-negative, mG/GEJ adenocarcinoma in China.

On average, participants assigned to zolbetuximab plus chemotherapy also lived 2.2 to 2.7 months longer, after starting the trial, than participants assigned to a placebo plus chemotherapy. These results suggest that zolbetuximab plus chemotherapy could be a new first treatment for people with CLDN18.2+ and HER2- stomach or GEJ cancer that is locally advanced unresectable or metastatic.Clinical Trial Registration: NCT03504397 (SPOTLIGHT); NCT03653507 (GLOW).

In conclusion, 123I-IMAB362 immuno-SPECT imaging offers an effective method for direct, noninvasive, and whole-body quantitative assessment of tumor CLDN18.2 expression in vivo. This approach holds promise for accelerating the monitoring and stratification of patients with gastric cancer.

P2, N=360, Not yet recruiting, Qilu Pharmaceutical Co., Ltd.

Phase 3 studies of zolbetuximab, a chimeric immunoglobulin G1 monoclonal antibody targeting CLDN18.2, combined with 5-fluorouracil/leucovorin plus oxaliplatin (modified FOLFOX6) or capecitabine plus oxaliplatin (CAPOX) in advanced or metastatic first-line gastric or gastroesophageal junction (G/GEJ) adenocarcinoma have demonstrated favorable clinical results with zolbetuximab. Furthermore, zolbetuximab combined with an anti-mouse programmed cell death-1 antibody more potently inhibited tumor growth compared with either agent alone. These results support the potential of zolbetuximab as a novel treatment option for G/GEJ adenocarcinoma.

P1, N=62, Completed, CARsgen Therapeutics Co., Ltd. | Active, not recruiting --> Completed | Trial completion date: Jun 2024 --> Sep 2023

P1/2, N=34, Completed, Zai Biopharmaceutical (Suzhou) Co., Ltd. | Recruiting --> Completed | N=162 --> 34 | Trial completion date: Oct 2024 --> Apr 2024

Zolbetuximab (IMAB362), an antibody specific for Claudin18.2, has been successfully tested in a phase III clinical trial, and the results of the study showed that combining Zolbetuximab with chemotherapy notably extends patients' survival and is expected to be a potential first-line treatment for patients with Claudin18.2(+)/HER-2(-) gastric cancer. Here, we systematically describe the biological properties and oncogenic effects of Claudin18.2, centering on its clinical-pathological aspects and the progress of drug studies in gastric cancer, which can help to further explore its clinical value.

CLDN18.2 will be an important target in GAC. Early understanding of how to target CLDN18.2 based on the level of expression (high, moderate, low) will be the key to success in this area. Studying these as separate entities should be considered. Resistance patterns, loss of CLDN18.2 expression, role in the refractory setting, and if any role in localized disease are questions that remain. Other targets for claudin that target claudin six and four are under investigation. Their role in GI malignancies will soon be further clarified.