Nanjing Leads Biolabs Co., Ltd. (Leads Biolabs) disclosed updated Phase I data for its GPRC5D/CD3 bispecific T-cell engager LBL-034 during an oral presentation at the 2026 ESMO Annual Meeting on 24 October 2026. The experimental therapy showed robust efficacy and a manageable safety profile in patients with relapsed/refractory multiple myeloma (RRMM) who had exhausted multiple prior treatments.
Patient Profile • As of 16 July 2026, the first-in-human trial had enrolled 56 RRMM patients with a median of 4.5 prior therapy lines (range: 3–12). • High disease complexity: 73.2 % were triple-class exposed, 57.1 % penta-drug exposed, and 60.7 % triple-class refractory. • Prior autologous stem-cell transplant and BCMA-directed CAR-T therapy had been administered to 28.6 % and 16.1 % of patients, respectively. Extramedullary disease (23.2 %) and high-risk cytogenetics (64.3 %) were common.
Efficacy Highlights (400–1,200 μg/kg cohorts, n = 41) • Median follow-up: 17.8 months. • Median progression-free survival (mPFS): 21.8 months; 15- and 18-month PFS rates were 62.0 % and 54.8 %, respectively. • Median duration of response (mDoR) not yet reached; 12- and 18-month DoR rates were 77.0 % and 68.4 %. • Time to complete response shortened with higher dosing: 5.60 months (400 μg/kg), 3.45 months (800 μg/kg), 3.06 months (1,200 μg/kg).
High-Risk Subgroup Outcomes • Extramedullary disease: 75.0 % overall response rate (ORR); 1,200 μg/kg cohort achieved 100 % ORR with rapid lesion shrinkage. • Prior BCMA-therapy failure: ORR 85.7 %; stringent complete response (sCR) 57.1 %. • Penta-drug exposed: ORR 73.9 %; sCR 34.8 %.
Safety Profile • No dose-limiting toxicities observed through 1,200 μg/kg; maximum tolerated dose not reached. • Cytokine release syndrome was predominantly low grade; only one Grade ≥3 event reported. • Two cases of ICANS resolved fully; no movement disorder or ataxia noted. • Adverse events were mostly Grade 1–2, concentrated in step-up dosing and cycle 1; incidence decreased in later cycles. Median treatment duration reached 11.3 months.
Mechanism and Regulatory Status LBL-034 is a 2:1 humanized bispecific antibody (two GPRC5D Fabs, one anti-CD3 scFv) generated via the proprietary LeadsBody platform to enable conditional T-cell activation and mitigate systemic toxicity. The candidate was granted U.S. FDA Orphan Drug Designation in October 2024 and Fast Track Designation in January 2026. Preparation for a Phase III clinical study is underway.
Caution Leads Biolabs emphasizes that development and commercialization of LBL-034 remain subject to clinical and regulatory outcomes, and no assurance can be given of eventual market approval.
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