LEADS BIOLABS-B (09887) announced that the 67th ASH Annual Meeting was held in Orlando, Florida, from December 6 to 9, 2025. On the first day of the conference, the company's self-developed GPRC5D/CD3 bispecific antibody, LBL-034, designed for treating relapsed/refractory multiple myeloma (RRMM), was featured as the first oral presentation.

The Phase I/II clinical study of LBL-034, led by Professor Lu Jin from Peking University People's Hospital, was conducted across 17 centers nationwide. The study demonstrated that LBL-034 exhibited favorable safety and promising antitumor activity in RRMM patients, including refractory subgroups with high-risk features, showcasing best-in-class therapeutic potential.

Key clinical highlights of LBL-034 include: - Dose escalation up to 1,200 μg/kg without any dose-limiting toxicity (DLT) observed, with the maximum tolerated dose (MTD) not reached. - Adverse events related to quality of life were all Grade 1–2, mostly occurring in the first cycle and significantly decreasing in subsequent treatments, without affecting treatment continuity. - Low incidence of taste, skin, and nail toxicities, with a tendency for self-resolution.

In the 400–1,200 μg/kg dose range (n=40), the objective response rate (ORR) was 82.5%, with ≥ complete response (CR) at 52.5%, ≥ very good partial response (VGPR) at 72.5%, and minimal residual disease (MRD) negativity at 80.0%. At the 800 μg/kg dose level, ORR and ≥ CR reached 90.9% and 63.6%, respectively.

Notably, excellent efficacy was also observed in refractory RRMM patients within the 400–1,200 μg/kg range. For patients with extramedullary disease (EMD), ORR was 75.0%, including two cases achieving stringent complete response (sCR). In the 1,200 μg/kg group, EMD patients achieved a 100% ORR, with rapid shrinkage of EMD lesions observed.

Among patients previously treated with BCMA-targeted therapy, ORR was 85.7%, with CR/sCR at 57.1%. A sustained benefit trend was observed in the 400–1,200 μg/kg range, with a 12-month progression-free survival (PFS) rate of 61.2% (median follow-up: 9.6 months). For the 400 μg/kg group (n=11), the median follow-up reached 13.1 months, with a 12-month PFS rate of 56.8%.