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- Non-clinical studies confirmed ABL503’s ability to restore the immune function of exhausted tumor infiltrating CD8+ T cells
- Studies also demonstrated that the combination of ABL503 and PD-1 blockade significantly inhibited tumor growth and enhanced the activation of TIL CD8+ T cells
- The study supports the exploration of the combination of ABL503 and anti-PD-1 inhibitors in improving anticancer effects in clinical trials
ABL Bio (CEO Sang Hoon Lee), a company specializing in bispecific antibody development, and Professor Soo Hyung Park’s research team at the Korean Advanced Institute of Science & Technology (KAIST) (President Gwang Hyeong Lee) Graduate School of Medical Sciences today announced the publication of non-clinical studies of ABL503 (ragistomig) in ‘Clinical Cancer Research (CCR)’, an internationally recognized journal of the American Association for Cancer Research (AACR).
ABL503 is a bispecific antibody that is being jointly developed by ABL Bio and its global partner I-Mab Biopharma using ABL Bio’s 4-1BB-based bispecific antibody platform ‘Grabody-T’. ABL503 simultaneously targets PD-L1, an immune checkpoint protein and 4-1BB, which is involved in immune T cell activation. It was developed to overcome the limited response rate and resistance to PD-(L)1 inhibitors as well as to improve off-target effects compared to other 4-1BB monoclonal antibodies. Promising data from Phase 1 clinical trials are underway in the United States and South Korea to evaluate ABL503 for patients with advanced solid tumors and were recently reported at the Annual Meeting of the American Society for Clinical Oncology (ASCO 2024).
The title of the paper, published by ABL Bio in CCR, is ‘Anti-4-1BB×PD-L1 Bispecific Antibody Reinvigorates Tumor-Specific Exhausted CD8+ T Cells and Enhances the Efficacy of Anti-PD-1 Blockade.’ The paper includes the encouraging results of non-clinical research on ABL503 combination therapy confirmed through in vitro and in vivo experiments. The study was jointly conducted by ABL Bio researchers, Professor Soo Hyung Park's research team at KAIST, Professor Seung Hyuk Jeon of Seoul National University Bundang Hospital, Professor Dae Hoon Han of Severance Hospital, and Professor Jun Sik Park of Soonchunhyang University Bucheon Hospital.
According to the paper, ABL503 restored the function of exhausted CD8+ T cells that did not respond to PD-1 inhibitors. The combination of ABL503 and a PD-1 inhibitor was confirmed to enhance the functional restoration of CD8+ T cells compared to PD-1 inhibitor monotherapy. Based on these results, the researchers explained that ABL503 may improve the anticancer effect of PD-1 inhibitor by enhancing the function of exhausted CD8+ T cells and inducing tumor growth inhibition.
Sang Hoon Lee, ABL Bio’s CEO said, “The non-clinical data reported in the CCR paper suggests that ABL503 has the potential to improve the anti-cancer efficacy of existing anti-PD1 agents. The combination of ABL503 and anti-PD1 treatments may show improved therapeutic effects in future clinical trials” and stated, “Encouraging Phase 1 results of ABL503 monotherapy were presented at ASCO 2024. Study results showed that treatment with ABL503 produced one complete response and six partial responses in patients previously treated with various types of anticancer drugs, including anti-PD-(L)1 therapy. Together, these data support further evaluation of ABL503 and its potential to become a globally recognized bispecific antibody.”
Meanwhile, ABL Bio is developing various clinical and non-clinical assets based on its bispecific antibody platform ‘Grabody’. More than 15 clinical projects for more than 7 assets, including ABL001, ABL111, ABL503, ABL105, ABL202, ABL301, and ABL103, are underway for different indications in various countries, including the United States, China, Australia, and Korea. In the case of ABL001, the U.S. Food and Drug Administration (FDA) recently granted Fast Track designation to support the rapid development of this new drug candidate. Meanwhile, ABL Bio is preparing to initiate clinical trials for ABL104. In addition, ABL Bio is continuously researching and developing several other product candidates, including bispecific antibody-drug conjugates (ADCs).