CSPC PHARMA (01093) has announced that results from the first-in-human Phase I/II clinical study of SYS6090 (JMT108), an anti-programmed death receptor 1 (PD-1)/interleukin-15 (IL-15) bispecific fusion protein developed by the company, in patients with advanced solid tumors were presented on October 25, 2026 at the 2026 European Society for Medical Oncology (ESMO) Congress as a rapid oral presentation (abstract number: 1009RO).
Professor Lin Rongbo from Fujian Provincial Cancer Hospital presented the findings on behalf of the research team. The presentation highlighted 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 including non-small cell lung cancer (NSCLC).
The study is an open-label, multicenter Phase I/II clinical trial 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 therapy. The Phase I portion included an accelerated titration cohort (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 a dose expansion phase to assess safety and preliminary efficacy; the Phase II portion consists of 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. Phase I study results 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, ORR reached 40.0% and 21.1%, respectively. These results support further evaluation of the product's clinical value 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 bispecific fusion protein incorporating IL-15, built on an Fc fragment (a mutated immunoglobulin G1 (IgG1) subtype designed to attenuate Fc-mediated immune functions). The product targets PD-1-positive (PD-1+) tumor-infiltrating immune cells through its left arm, blocking the immunosuppressive effects resulting from the interaction between PD-1 and programmed death ligand 1 (PD-L1); and binds to the IL-15 receptor through its right arm, activating downstream signaling pathways to further promote the activation and proliferation of relevant immune cells. Additionally, the product's unique molecular design can both reduce the expression level of PD-1 on the surface of PD-1+ cells and weaken binding to the 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 company is actively advancing subsequent combination therapy exploration and plans to initiate pivotal clinical studies as soon as possible.