Novel ADC Receives FDA Fast Track Designation for Pancreatic Cancer

Grade 3 or higher neutropenia occurred in most patients.

The FDA has granted EBC-129, a novel antibody-drug conjugate (ADC), fast track designation for use in pancreatic ductal adenocarcinoma, according to a news release from The Experimental Drug Development Centre in Singapore.¹

The fast track designation facilitates the expedited development of EBC-129, allowing for more frequent discussion with the FDA as well as providing potential eligibility for priority review and accelerated approval, as well as rolling review of any future biologic license application.

"The FDA's fast track designation for EBC-129 underscores the promise of this novel ADC in addressing the critical need for expanded treatment options for [patients with] PDAC and represents an important step in our efforts to accelerate its development. We view this as both a validation of our efforts and a responsibility to move decisively to advance EBC-129 as a new option to patients in need," said Professor Damian O'Connell, chief executive officer of Experimental Drug Development Center, in a press release.

EBC-129 selectively targets a tumor-specific N-glycosylated epitope on both CEACAM5 and CEACAM6. The agent is being assessed in a phase 1 trial, and updated findings from the dose-escalation and dose-expansion portions will be presented at the 2025 ASCO Annual Meeting.

A total of 21 patients with PDAC were enrolled in the trial, with 6 in the dose-escalation portion and 15 in the dose-expansion portion.² At the data cut-off of January 16, 2025, 5 patients were continuing treatment, 12 had radiological progression, 3 had clinical progression, and 1 patient withdrew.

The overall response rate (ORR) at the 1.8 mg/kg and 2.2 mg/kg dose levels were 25.0% and 18.2%, respectively, with an ORR for all patients of 19.0% and 43% of patients experiencing any tumor shrinkage. The disease control rate (DCR) was 87.5%, 63.6%, and 71.4% at the 1.8 mg/kg and 2.2 mg/kg dose levels and in the whole population, respectively. The median progression-free survival (PFS) was 18 weeks, 12 weeks, and 12 weeks, respectively.

Regarding safety, 57% of patients experienced infusion-related reactions, with most being grade 1 or 2 and more frequently occurring at the 2.2 mg/kg dose level. Most reactions were resolved or reduced with premedication. Grade 3 or higher treatment-related adverse events in the 1.8 mg/kg and 2.2 mg/kg dose levels included neutropenia (50.0% vs 81.8%) and anemia (12.5% vs 18.2%). Increased amylase/lipase, vomiting, and increased aspartate aminotransferase were observed in 1 patient each, and grade 2 or higher peripheral neuropathy was observed in 2 patients.

The study is continuing recruitment in Colorado, Texas, and Singapore, with sites in Taiwan not yet recruiting.³

Reference

1. Experimental Drug Development Centre granted U.S. FDA fast track designation for antibody-drug conjugate EBC-129 to treat pancreatic ductal adenocarcinoma. News release. The Experimental Drug Development Centre. May 28, 2025. Accessed May 29, 2025. https://tinyurl.com/yv3rtm3w
2. Lentz R, Ng M, Yong W, et al. Clinical activity of EBC-129, a first-in class, anti N256-glycosylated CEACAM5 and CEACAM6 antibody-drug conjugate (ADC), in patients with pancreatic ductal adenocarcinoma (PDAC) in a phase 1 study. Presented at: 2025 ASCO Annual Meeting; May 30-June 3, 2025; Chicago, IL. Abstract 4018.
3. A study of EBC-129 in advanced solid tumours. ClinicalTrials.gov. Updated May 20, 2025. Accessed May 29, 2025. https://clinicaltrials.gov/study/NCT05701527