Singapore, 3 June 2025 – The Experimental Drug Development Centre (EDDC), Singapore's national platform for drug discovery and development, has announced the presentation of updated clinical data for the ongoing Phase 1 trial for EBC-129 at the 2025 Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago.
EBC-129 is a first-in-class antibody drug conjugate (ADC) targeting a novel, tumour-specific N256-glycosylated epitope on CEACAM5 and CEACAM6. The updated findings showed promising efficacy data from 21 heavily pre-treated pancreatic ductal adenocarcinoma (PDAC) patients across the dose escalation and the dose expansion portions of the Phase 1 study. Patients received EBC-129 at doses between 1.8 and 2.2 mg/kg, given once every 3 weeks. 17 out of 21 patients (81%) of the patients had received prior treatment with taxanes. 82% of patients had tumours which expressed the EBC-129 antigen at ≥1% at 3+ intensity and were therefore considered treatable. The overall response rates (ORRs) were 25% and 20%, with disease control rates (DCRs) of 87.5% and 63.6% and progression-free survival (PFS) of 19 and 12 weeks for 1.8 mg/kg and 2.2 mg/kg, respectively.
"Pancreatic adenocarcinoma remains one of the most challenging cancers to treat, particularly in the metastatic setting where resistance to standard therapies is common. The clinical signals observed with EBC-129 in refractory pancreatic adenocarcinoma, including tolerability, prolonged disease control and a confirmed response in a heavily pre-treated patient, are encouraging and clinically meaningful. Continued prioritisation of biology-guided trials targeting EBC-129 will be key to sustaining momentum in this important therapeutic effort," said Assistant Professor Robert W. Lentz, MD, Division of Medical Oncology, Department of Medicine, University of Colorado Anschutz School of Medicine.
This presentation follows the recent Fast Track Designation granted by the U.S. FDA for EBC-129 in the treatment of PDAC patients. This designation supports EDDC's efforts to accelerate the advancement of the programme through increased regulatory engagement and the potential for expedited review pathways.
Other Results to Date
The dose escalation study of the Phase 1 trial was open to all patients, while the ongoing dose expansion study comprises of three cohorts in PDAC, gastroesophageal adenocarcinoma (GEA) and tumour-agnostic patients with other immunohistochemistry (IHC)-positive solid tumours. Recruitment for the GEA and IHC-positive cohorts is still ongoing.
EBC-129 showed a manageable safety profile in the 58 patients treated so far, with uncomplicated neutropenia and infusion-related reactions as the main treatment-related adverse events (TRAEs) observed.
The EBC-129 antigen was also found to be highly expressed, with 52% to 100% of tumour tissues assessed during the trial showing moderate to high expression levels of ≥20% at 2+ and/or 3+. This included samples from gastroesophageal, appendiceal, colorectal and lung cancer patients, making EBC-129 a potentially viable treatment option for these cancers.
"We have seen encouraging signs of efficacy of EBC-129 as a single-agent therapy, even in heavily pre-treated patients with metastatic pancreatic cancer. This, combined with the observed safety profile, underscores the promise of EBC-129 as a possible treatment option for PDAC patients. As a first-in-class ADC that targets both CEACAM5 and CEACAM6, EBC-129 has also shown potential against a range of other solid tumours, and we look forward to expanding clinical evaluations with the ongoing dose expansion cohorts and accelerating the development of EBC-129 to address critical unmet needs in cancer," said Professor Damian O'Connell, CEO of EDDC.
About EBC-129
EBC-129 is an ADC that targets a tumour-specific N256-glycosylation site conserved on CEACAM5 and CEACAM6. CEACAM5 and CEACAM6 are known to have functional importance in tumour formation, migration and metastasis. In the ongoing trial, the tumour-specific marker is found to be widely expressed in multiple solid tumour types, including gastric, oesophageal, pancreatic, lung, colorectal, and appendiceal cancers, based on an analytically validated immunohistochemistry (IHC) assay. The payload used in EBC-129 is monomethyl auristatin E (MMAE), which has been extensively tested and approved for clinical use in other marketed ADCs, and has demonstrated synergy with PD-1 inhibitors. The ongoing Phase 1 trial of EBC-129 is assessing the safety and tolerability of EBC-129 as a single agent and in combination with pembrolizumab in patients with advanced solid tumours. Enrolment for the PDAC cohort in the Phase 1 dose expansion study is now complete, while recruitment continues for the gastroesophageal adenocarcinoma (GEA) and IHC-positive cohorts.
