CSPC PHARMA (01093): Results of the Phase I/II Clinical Study of the Anti-PD-1/IL-15 Bifunctional Fusion Protein SYS6090 (JMT108) as Monotherapy for Advanced Solid Tumors Presented as a Rapid Oral Presentation at the 2026 ESMO Congress

CSPC PHARMA (01093) announced that the results of the first-in-human Phase I/II clinical study (the "Study") of SYS6090 (JMT108) (the "Product"), an anti-programmed death receptor 1 (PD-1)/interleukin-15 (IL-15) bifunctional fusion protein developed by the Group, in patients with advanced solid tumors were presented as a rapid oral presentation (number: 1009RO) at the 2026 European Society for Medical Oncology (ESMO) Congress on October 25, 2026. The Study was presented by Professor Lin Rongbo of Fujian Cancer Hospital on behalf of the research team. This presentation focused on disclosing the preliminary efficacy and safety data of the Product in patients with hepatocellular carcinoma (HCC) and colorectal cancer (CRC), and reported partial responses observed in other tumor types such as non-small cell lung cancer (NSCLC). The Study is an open-label, multicenter Phase I/II clinical study designed to evaluate the efficacy and safety of the Product in patients with advanced malignant solid tumors who have progressed on or are intolerant to standard treatment. The Phase I study included an 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, once every 2 weeks) and dose expansion phase to evaluate safety and preliminary efficacy; the Phase II study is a cohort expansion in selected tumor types and is currently still enrolling patients. The primary endpoints of the Study include safety, objective response rate (ORR) and pharmacokinetics. The data cutoff date for this presentation was April 13, 2026. Results from the Phase I study showed that the Product demonstrated a manageable safety profile and preliminary antitumor activity in patients with advanced solid tumors. Among evaluable patients with HCC and CRC, the ORR reached 40.0% and 21.1%, respectively. These results support further evaluation of the clinical value of the Product in CRC, HCC and other tumor types. The Phase II cohort expansion study is progressing smoothly with patient enrollment. The Product is a recombinant fully human anti-PD-1 asymmetric bifunctional crystallizable fragment (Fc, a mutated immunoglobulin G1 (IgG1) subtype, to attenuate Fc-mediated immune functions) fusion protein fused with IL-15. The Product targets PD-1-positive (PD-1+) tumor-infiltrating immune cells through its left arm, blocking the immunosuppressive function caused by the interaction between PD-1 and programmed death ligand 1 (PD-L1); and binds to the IL-15 receptor through its right arm, activating its downstream signaling pathways to further promote the activation and proliferation of relevant immune cells. In addition, the unique molecular design of the Product can both reduce the expression abundance of PD-1 on the surface of PD-1+ cells and attenuate binding to the interleukin-2 receptor beta subunit (IL-2R) and interleukin-2 receptor gamma subunit (IL-2R) 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 advancing subsequent combination therapy exploration and plans to initiate pivotal clinical studies as soon as possible.