US-based clinical-stage biotechnology company SystImmune, Inc announced on Monday that it has received US Food and Drug Administration clearance for its Investigational New Drug application for BL-M11D1, an antibody-drug conjugate targeting CD33 on myeloid cells.

This approval supports the launch of a Phase 1 clinical trial, BLM11D1-HM-101, to assess the safety, tolerability, pharmacokinetics and preliminary efficacy of BL-M11D1 in patients with relapsed or refractory Acute Myeloid Leukemia.

Dr Jonathan Cheng, CMO at SystImmune, said that receiving the FDA Study-May-Proceed letter enables the initiation of our Phase 1 study with BL-M11D1, we believe that this novel, potentially best-in-class ADC can offer an important therapeutic option for patients with relapsed/refractory AML and look forward to implementing this study.

BL-M11D1 combines a CD33-binding monoclonal antibody with a topoisomerase I inhibitor, linked by a stable enzyme-cleavable linker. Upon binding to CD33, BL-M11D1 induces antibody-dependent cellular cytotoxicity and releases its cytotoxic payload, killing the tumour cells. FDA clearance marks a significant milestone in advancing SystImmune's clinical pipeline.