The addition of an extended lymphadenectomy and retroperitoneal soft-tissue clearance to a pancreatoduodenal resection does not significantly increase morbidity and mortality rates. Although the overall survival rate does not differ in the two groups, there appears to be a trend toward longer survival in node positive patients treated with an extended rather than a standard lymphadenectomy.
Purpose: Antibody-based cancer therapies have emerged as the most promising therapeutics in oncology. The purpose of this study was to discover novel targets for therapeutic antibodies in solid cancer. Experimental Design:We combined data mining and wet-bench experiments to identify strictly gastrocyte lineage^specific cell surface molecules and to validate them as therapeutic antibody targets. Results: We identified isoform 2 of the tight junction molecule claudin-18 (CLDN18.2) as a highly selective cell lineage marker. Its expression in normal tissues is strictly confined to differentiated epithelial cells of the gastric mucosa, but it is absent from the gastric stem cell zone. CLDN18.2 is retained on malignant transformation and is expressed in a significant proportion of primary gastric cancers and the metastases thereof. In addition to its orthotopic expression, we found frequent ectopic activation of CLDN18.2 in pancreatic, esophageal, ovarian, and lung tumors, correlating with distinct histologic subtypes. The activation of CLDN18.2 depends on the binding of the transcription factor cyclic AMP^responsive element binding protein to its unmethylated consensus site. Most importantly, we were able to raise monoclonal antibodies that bind to CLDN18.2 but not to its lung-specific splice variant and recognize the antigen on the surface of cancer cells. Conclusions: Its highly restricted expression pattern in normal tissues, its frequent ectopic activation in a diversity of human cancers, and the ability to specifically target this molecule at the cell surface of tumor cells qualify CLDN18.2 as a novel, highly attractive pan-cancer target for the antibody therapy of epithelial tumors.Gastroesophageal and pancreatic cancers are among the malignancies with the highest unmet medical needs (1). Gastric cancer is the second leading cause of cancer death worldwide. In 2002, f1.4 million people worldwide developed gastroesophageal cancers and 1.1 million died (2). Esophageal cancer incidence has increased in recent decades, coinciding with a shift in histologic type and primary tumor location. Adenocarcinoma of the esophagus is now more prevalent than squamous cell carcinoma in the United States and Western Europe, with most tumors located in the distal esophagus (3).The overall 5-year survival rates for gastroesophageal cancers are 20% to 25% despite the aggressiveness of established standard treatments associated with substantial side effects (4, 5). For pancreatic cancer, there is an even greater medical need. Due to the advanced state of the disease at the time of diagnosis, the prognosis is extremely poor, with median survival times of less than 6 months and a 5-year survival rate of <5.5%. The lack of a major benefit from the various newergeneration combination chemotherapy regimens for these cancers has stimulated research into the use of targeted agents, such as small molecule -based kinase inhibitors and monoclonal antibodies (mAb; ref. 6). However, mAbs, such as bevacizumab, cetuximab, and trastuzumab...
Background: Claudin 18.2 (CLDN18.2) is contained within normal gastric mucosa epithelial tight junctions; upon malignant transformation, CLDN18.2 epitopes become exposed. Zolbetuximab, a chimeric monoclonal antibody, mediates specific killing of CLDN18.2-positive cells through immune effector mechanisms. Patients and methods: The FAST study enrolled advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients (aged 18 years) with moderate-to-strong CLDN18.2 expression in 40% tumour cells. Patients received first-line epirubicin þ oxaliplatin þ capecitabine (EOX, arm 1, n ¼ 84) every 3 weeks (Q3W), or zolbetuximab þ EOX (loading dose, 800 mg/m 2 then 600 mg/m 2 Q3W) (arm 2, n ¼ 77). Arm 3 (exploratory) was added after enrolment initiation (zolbetuximab þ EOX 1000 mg/m 2 Q3W, n ¼ 85). The primary endpoint was progression-free survival (PFS) and overall survival (OS) was a secondary endpoint. Results: In the overall population, both PFS [hazard ratio (HR) ¼ 0.44; 95% confidence interval (CI), 0.29-0.67; P < 0.0005] and OS (HR ¼ 0.55; 95% CI, 0.39-0.77; P < 0.0005) were significantly improved with zolbetuximab þ EOX (arm 2) compared with EOX alone (arm 1). This significant PFS benefit was retained in patients with moderate-tostrong CLDN18.2 expression in 70% of tumour cells (HR ¼ 0.38; 95% CI, 0.23-0.62; P < 0.0005). Significant improvement in PFS was also reported in the overall population of arm 3 versus arm 1 (HR ¼ 0.58; 95% CI, 0.39-0.85; P ¼ 0.0114) but not in high CLDN18.2-expressing patients; no significant improvement in OS was observed in either population. Most adverse events (AEs) related to zolbetuximab þ EOX (nausea, vomiting, neutropenia, anaemia) were grade 1-2. Grade 3 AEs showed no substantial increases overall (zolbetuximab þ EOX versus EOX alone). Conclusions: In advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients expressing CLDN18.2, adding zolbetuximab to first-line EOX provided longer PFS and OS versus EOX alone. Zolbetuximab þ EOX was generally tolerated and AEs were manageable. Zolbetuximab 800/600 mg/m 2 is being evaluated in phase III studies based on clinical benefit observed in the overall population and in patients with moderate-to-strong CLDN18.2 expression in 70% of tumour cells.
BackgroundClaudin 18.2 (CLDN18.2) is physiologically confined to gastric mucosa tight junctions; however, upon malignant transformation, perturbations in cell polarity lead to CLDN18.2 epitopes being exposed on the cancer cell surface. The first-in-class monoclonal antibody, zolbetuximab (formerly known as IMAB362), binds to CLDN18.2 and can induce immune-mediated lysis of CLDN18.2-positive cells.Patients and methodsPatients with advanced gastric, gastro-oesophageal junction (GEJ) or oesophageal adenocarcinomas with moderate-to-strong CLDN18.2 expression in ≥50% of tumour cells received zolbetuximab intravenously every 2 weeks for five planned infusions. At least three patients were enrolled in two sequential cohorts (cohort 1300 mg/m2; cohort 2600 mg/m2); additional patients were enrolled into a dose-expansion cohort (cohort 3600 mg/m2). The primary end point was the objective response rate [ORR: complete and partial response (PR)]; secondary end points included clinical benefit [ORR+stable disease (SD)], progression-free survival, safety/tolerability, and zolbetuximab pharmacokinetic profile.ResultsFrom September 2010 to September 2012, 54 patients were enrolled (cohort 1, n = 4; cohort 2, n = 6; cohort 3, n = 44). Three patients in cohort 1 and 25 patients in cohorts 2/3 received at least 5 infusions. Antitumour activity data were available for 43 patients, of whom 4 achieved PR (ORR 9%) and 6 (14%) had SD for a clinical benefit rate of 23%. In a subgroup of patients with moderate-to-high CLDN18.2 expression in ≥70% of tumour cells, ORR was 14% (n = 4/29). Treatment-related adverse events occurred in 81.5% (n = 44/54) patients; nausea (61%), vomiting (50%), and fatigue (22%) were the most frequent.ConclusionsZolbetuximab monotherapy was well tolerated and exhibited antitumour activity in patients with CLDN18.2-positive advanced gastric or GEJ adenocarcinomas, with response rates similar to those reported for single-agent targeted agents in gastric/GEJ cancer trials.ClinicalTrials.gov numberNCT01197885.
In the mid 1990s, the hypothesis emerged that the upregulation or re-expression of a telomere-synthesising ribonucleoprotein, called telomerase, is a critical event responsible for continuous tumour cell growth. In contrast to normal cells, in which gradual mitosis-related erosion of telomeres eventually limits replicative life span, tumour cells have telomerase and show no loss of these chromosomal ends. These data suggest that telomere stabilisation may be required for cells to escape replicative senescence and to proliferate indefinitely. Because of the close association between telomerase and malignancy, both pathologists and clinicians expect this molecule to be a useful malignancy-marker and a new therapeutic target. This review focuses on the components of the human telomere and of the human telomerase enzyme. A synopsis of reports studying the clinical-diagnostic value of telomere length measurements, of telomerase activity analyses and of the in situ telomerase detection is given. Finally, a summary of recent experimental work that sheds new light on the biological role of this fascinating molecule is presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.