Shiyao Group (01093): The results of the phase I/II clinical study of anti-PD-1/IL-15 bifunctional fusion protein SYS6090 (JMT108) single-agent treatment of advanced solid tumors were announced in the form of a quick oral report at the 2026 ESMO annual meeting

Zhitong Finance App News, Shiyao Group (01093) issued an announcement. The results of the first human phase I/II clinical study (this study) of SYS6090 (JMT108), an anti-procedural death receptor 1 (PD-1) /interleukin-15 (IL-15) bifunctional fusion protein developed by the Group in patients with advanced solid tumors (this study) were announced in the form of a quick oral report (ID: 1009RO) on October 25, 2026 at the 2026 European Society of Medical Oncology (ESMO) annual meeting.

The study was reported by Professor Lin Rongbo of Fujian Cancer Hospital on behalf of the research team. This report focuses on initial efficacy and safety data of this product in patients with hepatocellular carcinoma (HCC) and colorectal cancer (CRC), and reports on some of the relief observed in other tumors such as non-small cell lung cancer (NSCLC).

The study is an open-label, multi-center phase I/II clinical study to evaluate the efficacy and safety of this product in patients with advanced malignant solid tumors who have progressed or are intolerant to standard treatments. The phase I study included accelerated titration (0.01 mg/kg, once every 2 weeks), Bayesian optimal interval design (BOIN) dose escalation (0.1, 0.3, 1, 2, and 3 mg/kg, every 2 weeks), and a dose expansion phase to evaluate safety and initial efficacy; the phase II study expanded the cohort for selected tumors, and patients are still being enrolled. Key endpoints of the study included safety, objective response rate (ORR), and pharmacokinetics. The deadline for this data report is April 13, 2026.

The results of the phase I study showed that the product showed controllable safety features and initial anti-tumor activity in patients with advanced solid tumors. Among the evaluable HCC and CRC patients, ORR reached 40.0% and 21.1%, respectively. The above results support further evaluation of the clinical value of this product in CRC, HCC and other tumors. The Phase II cohort expansion study is successfully advancing patient enrollment.

This product is a recombinant all-human anti-PD-1 fusion protein with an asymmetrical structural bifunctional crystallizable fragment (Fc, a mutated immunoglobulin G1 (IgG1) subtype to reduce Fc segment-mediated immune function). The product targets PD-1 positive (PD-1 +) tumors in the left arm to infiltrate immune cells, blocks immunosuppressive function caused by the interaction between PD-1 and programmed death ligand 1 (PD-L1); and binds to IL-15 receptors through its right arm to activate downstream signaling pathways, further promoting the activation and proliferation of related immune cells.

Furthermore, the product's unique molecular design can not only reduce the abundance of PD-1 expression on PD-1 cell surface, but also reduce binding to interleukin-2 receptor beta subunit (IL-2Rβ) and interleukin-2 receptor gamma subunit (IL-2Rγ) on PD-1 negative cells, thereby reducing systemic toxicity induced by activation of non-targeted immune cells. Based on the positive data from this solid tumor study, the Group is currently actively promoting subsequent joint drug use exploration and plans to launch key clinical studies as soon as possible.