China-based Kelun-Biotech has presented Phase I data for CLDN18.2 antibody-drug conjugate (ADC) SKB315 at the European Society for Medical Oncology (ESMO) congress, showing 37.5% objective response rate (ORR) and 8.2 month median progression-free survival (mPFS) in heavily pretreated gastric/gastroesophageal junction cancer patients. The candidate demonstrated manageable safety profile with 39.7% grade three or higher treatment-related adverse events (TRAEs), primarily haematological toxicities, without treatment-related deaths. SKB315 utilises novel topoisomerase I inhibitor payload with cleavable linker technology enabling bystander effect and reduced gastric toxicity through stable circulation and tumour-specific payload release.

The competitive CLDN18.2 ADC landscape includes Innovent Biologics' IBI343 showing 47.1% ORR at 8mg/kg dosing and Hengrui Medicine's SHR-A1904 with 25.0% response in high expressors. SKB315's differentiated design features a pH-sensitive cleavable linker and optimised drug-to-antibody ratio (DAR), demonstrating superior pre-clinical affinity and proliferation inhibition versus zolbetuximab. Kelun-Biotech plans combination studies with immunotherapy in first-line gastric cancer alongside expansion into pancreatic cancer and other CLDN18.2-positive malignancies.

PharmCube's NextBiopharm® database shows that SKB315 is under development in seven oncology indications. Click here to request a free trial for NextBiopharm®.