Mabwell (688062.SH), an innovation-driven biopharmaceutical company with a fully integrated industry chain, announced that the National Medical Products Administration (NMPA) has accepted the Investigational New Drug (IND) application for its innovative LILRB4/CD3 TCE bispecific antibody (R&D code: 6MW5311). The drug candidate is being developed for hematologic malignancies, specifically Acute Myeloid Leukemia (AML), Chronic Myelomonocytic Leukemia (CMML), and Multiple Myeloma (MM).

6MW5311 is the world's first innovative LILRB4/CD3 TCE bispecific antibody for which a clinical trial application has been submitted. It possesses broad prospects for clinical development and significant market potential. The U.S. IND application is currently in the pre-IND phase, with plans to formally submit it to the FDA in the second quarter of 2026.

6MW5311 is developed based on the T Cell Engager (TCE) technology platform and features a "2+1" asymmetric molecular structure. It simultaneously targets LILRB4 and CD3, forming an immunological synapse by bridging tumor cells and T cells, thereby activating T cells to efficiently kill tumors.

The molecule incorporates a unique steric hindrance design. This structure significantly reduces the binding activity of the CD3 antibody to T cells in the absence of tumor cells. T cells are specifically activated only when tumor cells are present, which substantially enhances safety while improving anti-tumor efficacy.

In vitro studies have demonstrated that 6MW5311 exhibits potent cytotoxic activity across multiple tumor cell lines and patient-derived samples. In vivo pharmacodynamic studies have shown that 6MW5311 achieves significant tumor inhibition in both LILRB4-high and LILRB4-low expressing AML tumor models. Notably, it achieved complete tumor clearance in high-expression models. Furthermore, 6MW5311 demonstrated a favorable safety profile in cynomolgus monkey safety evaluation models.

As a key technological approach for directly mobilizing T cells to kill tumors, TCE has shown significant clinical value in various lymphoma indications, with multiple products successfully launched. However, current treatments for AML and CMML primarily remain primarily limited to chemotherapy, hematopoietic stem cell transplantation, and targeted therapies for specific mutations; no TCE products have been approved for these indications to date.