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- Significant improvement in the overall safety profile of ABL503/ragistomig administered as a monotherapy at a 6-week interval
- Enhanced T-cell immune memory along with favorable modulation of the tumor microenvironment
Seoul (South Korea) – December 12, 2025, ABL Bio (CEO Sang Hoon Lee), a company specializing in bispecific antibodies, today announced that it successfully finished the poster presentation for ABL503/ragistomig at the European Society for Medical Oncology Immuno-Oncology Congress (ESMO IO) 2025, held on December 10.
ABL503/ragistomig is a PD-L1/4-1BB bispecific antibody co-developed by ABL Bio and NovaBridge Biosciences. It is designed to activate immune cells through 4-1BB only within the PD-L1–expressing tumor microenvironment. While PD-1/PD-L1 blockade inhibits cancer cells, 4-1BB is a target involved in activating T-cell proliferation and immune-memory function.
The 6-week interval (Q6W) monotherapy regimen of ABL503/ragistomig was evaluated in 20 patients with relapsed or refractory solid tumors who had previously received immuno-oncology (IO) therapy and exhibited PD-L1 expression. Among them, 17 patients were included in the efficacy analysis set. These participants represented a high unmet medical need population with no remaining standard treatment options.
“According to the poster presented at the conference, encouraging antitumor activity was maintained even when the dosing interval of ABL503/ragistomig was extended from every 2 weeks (Q2W) to every 6 weeks (Q6W), with a Disease Control Rate (DCR) of 58.8%. Among patients who had previously been exposed to PD-(L)1 inhibitors but had relapsed or were refractory, two cases of Partial Response (PR) were reported.
In addition, the 6-week interval monotherapy of ABL503/ragistomig demonstrated a markedly improved overall safety profile, with treatment-related adverse events of Grade 3 or higher occurring in 15% (3/20) of patients and Grade ≥3 elevations in liver function tests observed in 5% (1/20). No patients discontinued the trial due to treatment-emergent adverse events while receiving ABL503/ragistomig on the Q6W schedule, and notably, no cases of cytokine release syndrome (CRS) were reported.
Sang Hoon Lee, CEO of ABL Bio, stated, “What is particularly noteworthy in this data presentation is that despite the reduced drug exposure resulting from the extended dosing interval, we observed enhanced T-cell immune-memory function as well as favorable modulation of the tumor microenvironment, which had previously hindered T-cell activation.” He continued, “Based on these results, the 6-week dosing of ABL503/ragistomig at 3 mg/kg is a candidate dose level for future combination-therapy development. After completing another dose cohort (5 mg/kg Q6W), ABL Bio plans to expand the clinical strategy of ABL503/ragistomig into combination therapies and identify the most suitable development partners.”
About ABL Bio
ABL Bio is developing various clinical and non-clinical assets based on its bispecific antibody platform ‘Grabody’. Clinical projects for 8 pipelines, including ABL301 (SAR446159), ABL001 (tovecimig), ABL111 (givastomig), ABL503 (ragistomig), ABL105 (YH32367), ABL104 (YH32364), ABL103, and ABL202 (CS5001/LCB71), are underway for different indications in various countries, including the United States, China, Australia, and Korea. Currently, ABL Bio and Sanofi are in the process of transferring the clinical trial sponsorship of ABL301 (SAR446159) to Sanofi to conduct following clinical studies. ABL001 (tovecimig) has received Fast Track designation by the U.S. Food and Drug Administration (FDA). In addition, ABL111 (givastomig), co-developed with NovaBridge, has presented encouraging data from the Phase 1b clinical trial evaluating the triple combination therapy with nivolumab and chemotherapy in ESMO GI 2025. In addition, ABL Bio is continuously researching and developing several other product candidates, including bispecific antibody-drug conjugates (ADCs).
About NovaBridge
NovaBridge is a global biotechnology platform company committed to accelerating access to innovative medicines. We combine deep business development expertise with agile translational clinical development to identify, accelerate, and advance breakthrough assets. By bridging science, strategy, and execution, NovaBridge enables transformative therapies to progress rapidly from discovery toward patients in need.
The Company’s differentiated pipeline is led by givastomig, a potential best-in-class, bispecific antibody (Claudin 18.2 x 4-1BB), and VIS-101, a second-in-class, potentially best-in-class bifunctional biologic, targeting VEGF-A and ANG2.
Givastomig conditionally activates T cells via the 4-1BB signaling pathway in the tumor microenvironment where Claudin 18.2 is expressed. Givastomig is being developed to treat Claudin 18.2-positive gastric cancer and other gastrointestinal malignancies. The Company is also collaborating with its partner, ABL Bio, for the development of ragistomig, a bispecific antibody integrating PD-L1 as a tumor engager and 4-1BB as a conditional T cell activator, in solid tumors. Additionally, NovaBridge owns worldwide rights outside of China to uliledlimab, an anti-CD73 antibody that targets adenosine-driven immunosuppression in cancer.
VIS-101 targets VEGF-A and ANG-2 to provide more potent and durable treatment benefits for patients with wet age-related macular degeneration (wet AMD) and diabetic macular edema (DME). VIS-101 is currently completing a large, randomized, dose-ranging Phase 2 study for wet AMD. NovaBridge is the majority shareholder of Visara, and Visara controls global rights to VIS-101, outside of Greater China and certain countries in Asia.