DA-3501 / Dong-A, AbTis - LARVOL DELTA

A First-In-Human Phase I/IIa Study to Evaluate DA 3501 in Patients With Advanced Gastric or Gastro-esophageal Junction Adenocarcinoma and Pancreatic Ductal Adenocarcinoma (clinicaltrials.gov) - P1 | N=51 | Recruiting | Sponsor: Dong-A ST Co., Ltd. | Not yet recruiting ➔ Recruiting | Initiation date: Feb 2026 ➔ May 2026

Enrollment open • First-in-human • Trial initiation date • Esophageal Cancer • Gastric Cancer • Gastroesophageal Cancer • Gastroesophageal Junction Adenocarcinoma • Oncology • Pancreatic Cancer • Pancreatic Ductal Adenocarcinoma • Solid Tumor • CLDN18

DA-3501 (AT-211): Evaluation of immune-mediated antitumor activity and combination immunotherapy potential of a site-specific CLDN18.2-targeting antibody-drug conjugate (ADC) (AACR 2026) - "However, acquired resistance to CLDN18.2-directed antibodies such as zolbetuximab and trastuzumab highlights the need for next-generation therapeutics with distinct mechanisms of action. DA-3501 (AT-211) is a site-selectively conjugated CLDN18.2-targeting ADC that exerts strong immune-mediated antitumor effects, even in models derived from patients resistant to existing antibody therapies. These results highlight the dual mechanism of action of DA-3501—combining direct cytotoxicity and Fc-driven immune activation—and support the development of rational ADC-immunotherapy combinations as a promising strategy in the evolving landscape of ADC-based cancer treatment."

ADC • IO biomarker • Gastric Cancer • Oncology • Pancreatic Cancer • Solid Tumor • CLDN18

Overcoming target heterogeneity in gastric cancer with an eKiH-engineered CLDN18.2×HER2 bispecific ADC (AACR 2026) - "We previously developed DA3501 (AT-211), a CLDN18.2-targeting ADC currently advancing toward Phase 1 evaluation. The DA3501 antibody clone demonstrates enhanced affinity and internalization compared with zolbetuximab... This BsAb is a rationally engineered CLDN18.2×HER2 bispecific ADC designed to overcome target heterogeneity in GC. Together with the DA3501 program, it broadens therapeutic coverage of CLDN18.2/HER2-expressing tumors and combination-strategy studies, including ICI co-therapy."

ADC • Bispecific • Heterogeneity • IO biomarker • Gastric Cancer • Oncology • Solid Tumor • CLDN18 • HER-2

…Dong-A ST and Aptis will present five posters on bispecific ADCs targeting CLDN18.2, HER2, AXL, NECTIN4, and PD-L1. [Google translation] (Korea IT Times) - "Among them, the CLDN18.2-targeting ADC, DA-3501 (AT-211), showed strong immune-mediated antitumor effects in gastric cancer models resistant to existing treatments. The bispecific ADC platform is expected to deliver more potent and durable anticancer effects compared to single-target therapies."

Preclinical • Gastric Cancer

A First-In-Human Phase I/IIa Study to Evaluate DA 3501 in Patients With Advanced Gastric or Gastro-esophageal Junction Adenocarcinoma and Pancreatic Ductal Adenocarcinoma (clinicaltrials.gov) - P1 | N=51 | Not yet recruiting | Sponsor: Dong-A ST Co., Ltd.

First-in-human • New P1 trial • Esophageal Cancer • Gastric Cancer • Gastroesophageal Cancer • Gastroesophageal Junction Adenocarcinoma • Oncology • Pancreatic Cancer • Pancreatic Ductal Adenocarcinoma • Solid Tumor • CLDN18

Dong-A ST files IND for gastric and pancreatic cancer ADC candidate DA-3501 (Chosun Biz) - "Dong-A ST announced on the 24th that its antibody-drug conjugate (ADC) subsidiary, Aptis, has filed an Investigational New Drug (IND) application to enter domestic Phase 1 clinical trials for the ADC candidate ‘DA-3501 (AT-211).’ The two companies plan to develop DA-3501 as a treatment for high-difficulty solid tumors such as gastric and pancreatic cancers."

IND • New P1 trial • Gastric Cancer • Pancreatic Cancer