Abstract 1963
Background
Claudin 18.2 (CLDN18.2), a gastric mucosa tight junction protein, is aberrantly expressed in various cancers. IMAB362, an anti-CLDN18.2 monoclonal antibody, specifically binds to CLDN18.2-positive cancer cells. This first-in-human (FIH), dose-escalation study evaluated the clinical effects of IMAB362 in patients with advanced gastroesophageal cancer (GEC) after a single IV infusion.
Methods
This phase 1 study (NCT00909025), conducted at 6 centers in Germany and Latvia, enrolled patients (≥18 yrs) with advanced GEC into 5 sequential dose-escalations cohorts (33, 100, 300, 600, 1000 mg/m2) that followed a 3 + 3 design. Safety/tolerability, including determination of maximum tolerated dose (MTD) based on emergence of dose-limiting toxicities (DLTs), was the primary objective; secondary objectives included assessment of the IMAB362 pharmacokinetic (PK) profile, immunogenicity, and antitumor activity (assessed by RECIST v1.0).
Results
All 15 enrolled patients (median age 61.3 years [range: 46–76]) had received ≥1 prior chemotherapy with nearly half (n = 7/15; 47%) having undergone previous radiotherapy. All IMAB362 doses tested were generally well tolerated; as no DLT was observed within 4 weeks of treatment the MTD was not established. Mild-to-moderate gastrointestinal disorders (eg, nausea, vomiting) were the most common treatment-related adverse events (AEs); however, no clear dose dependency was observed. Neither of the 2 serious AEs (grade 2 odynophagia [300 mg/m2]; grade 3 urinary retention [600 mg/m2]) was considered treatment related. No antibodies against IMAB362 were detected. Most patients (n = 12/15; 80%) showed progressive disease at Weeks 4–5 after a single IMAB362 IV infusion; however, 1 patient in the 600 mg/m2 dose group had stable disease for ∼2 months postinfusion. The linear, dose-proportional PK profile supports IMAB362 dosing at 300–600 mg/m2 every 2 weeks.
Conclusions
Single-dose administration of IMAB362 was well tolerated up to 1000 mg/m2 in this FIH dose-escalation study. These results encourage further clinical testing of IMAB362 in patients with CLDN18.2-positive GEC.
Clinical trial identification
NCT00909025, May 18, 2009
Legal entity responsible for the study
Ganymed Pharmaceuticals AG, A company of Astellas Pharma, Inc.
Funding
Ganymed Pharmaceuticals AG, A company of Astellas Pharma, Inc.
Disclosure
U. Sahin: Stock option owner, ex-shareholder and cofounder of Ganymed Pharmaceuticals AG, founder, CEO, shareholder of Biontech Holding, several patents issued to this work that have been acquired by Astellas. M. Schuler: Work at University Hospital Essen, University Duisburg-Essen and Rurlandklinik. Grant from Novartis, personal fees from AstraZeneca, Boehringer Ingelheim, BMS, Celgene, Lilly, Novartis, Roche, Alexion, MSD. M. Utsch: Employee of Ganymed Pharmaceuticals AG, a company of Astellas Pharma, Inc, patent PCT/EP2012/002210 issued. C. Huber: Grants from Fed. Min. of Ed. & Res GER, during conduct of study, personal fees from Ganymed Pharmaceuticals AG & Biontech, grants from and board member of cluster individualized imt-ci3, and president Assoc. CIMT. Ö. Türeci: Stock option owner, ex-shareholder, cofounder & CEO of Ganymed Pharmaceuticals AG, consultancy fees from Astellas, several patents issued to this work that have been acquired by Astellas. All other authors have declared no conflicts of interest.