Investigational Drug
ASP2138
TrialFetch AI Analysis
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Overview
ASP2138 is an investigational treatment for cancers whose cells express claudin 18.2 (CLDN18.2). Early human results have been reported from a phase 1/1b trial in gastric, gastroesophageal-junction and pancreatic cancer. The findings are preliminary and do not establish whether ASP2138 improves survival or adds benefit to standard treatment. (annalsofoncology.org)
Mechanism of action
ASP2138 is a bispecific antibody designed to bind CLDN18.2 on cancer cells and CD3 on T cells, bringing the cells together so T cells can attack the cancer. (annalsofoncology.org)
Efficacy
In previously treated gastric or gastroesophageal-junction cancer, intravenous ASP2138 alone produced five partial responses among 36 patients given doses of at least 420 μg. At 12 weeks, 15 of those 36 patients (41.7%) had an unconfirmed partial response or stable disease. (annalsofoncology.org)
For subcutaneous ASP2138 combined with standard treatments, the sponsor reported unconfirmed objective response rates of 62.5% (15/24) with first-line pembrolizumab plus mFOLFOX6 and 37.5% (9/24) with second-line ramucirumab plus paclitaxel, at the 2,000 μg ASP2138 dose. These small, nonrandomized groups cannot show how much ASP2138 contributed to the responses. (astellas.com)
Safety
Among 132 patients given intravenous ASP2138 alone, 102 (77.3%) had a treatment-related adverse event. Cytokine-release syndrome occurred in 43.2% of patients with gastric or gastroesophageal-junction cancer and 23.4% of those with pancreatic cancer; grade 3 cytokine-release syndrome occurred in 3.7% of the gastric or gastroesophageal-junction group. Nausea and fever were also commonly reported. (annalsofoncology.org)
Further reading
- Phase 1/1b monotherapy results, Annals of Oncology
- Phase 1/1b monotherapy and combination abstract, Annals of Oncology
- Combination-response data, Astellas presentation
Last updated: Sep 2026
Active trials using ASP2138
Found 2 active trials using this drug:
TrialFetch AI summary: Adults with previously untreated, locally advanced unresectable or metastatic HER2-negative, CLDN18.2-positive gastric or GEJ adenocarcinoma and ECOG performance status 0–1 receive ASP2138 plus pembrolizumab and CAPOX or mFOLFOX6, or placebo plus chemotherapy with or without pembrolizumab. ASP2138 is an investigational CLDN18.2×CD3 bispecific antibody designed to direct T cells against CLDN18.2-expressing tumor cells.
ClinicalTrials.gov ID: NCT07673887
TrialFetch AI summary: Adults with CLDN18.2-positive, locally advanced unresectable or metastatic gastric/GEJ or pancreatic adenocarcinoma and ECOG 0–1 receive ASP2138 alone or in disease- and treatment-line–specific combinations with pembrolizumab plus mFOLFOX6, ramucirumab plus paclitaxel, or mFOLFIRINOX. ASP2138 is an investigational bispecific antibody that binds CLDN18.2 on tumor cells and CD3 on T cells to recruit T-cell activity.
ClinicalTrials.gov ID: NCT05365581
