31 July 2023, Shanghai – Abbisko Therapeutics Co., Ltd. (“Abbisko Therapeutics” hereafter) announced that the clinical results of first-in-human study of FGFR4 inhibitor Irpagratinib（ABSK011）and the clinical results of first-in-human dose-escalating of PD-L1 inhibitor ABSK043 with advanced solid tumors will be presented at the 2023 European Society for Medical Oncology（ESMO）annual meeting to be held in Spain, from October 20 to 24, 2023. The Irpagratinib phase 1b data, since the first announcement at the end of 2022, includes further updates after enrolling more patients. Both research results will be the first of such release by a Chinese company for the respective target.

Abstract number: 1012P

Title: First-in-human study of ABSK011, a novel, highly selective fibroblast growth factor receptor (FGFR) 4 inhibitor for treating advanced hepatocellular carcinoma (HCC) with FGF19 overexpression.

Time：20-24 October 2023

Abstract number: 700P

Title: First-in-human dose-escalating study of ABSK043, a novel and oral small-molecule inhibitor of PD-L1, in patients with advanced solid tumors.

Time：20-24 October 2023

About Irpagratinib (ABSK011)

Irpagratinib (ABSK011) is a potent and highly selective small molecule inhibitor of FGFR4. Irpagratinib is being developed for the treatment of advanced HCC with hyperactivation of FGF19/FGFR4 signaling. The research studies have shown that about 30% of global HCC patients have FGF19/FGFR4 signaling, thus，the FGFR4 signaling pathway is a promising direction for the development of molecular targeted therapies in HCC. Irpagratinib demonstrated improved potency and anti-tumor efficacy compared to competitors as well as favorable physical-chemical properties in preclinical studies. According to Frost & Sullivan and the global competitive landscape of FGFR4 inhibitors, we believe that Irpagratinib is potentially a novel and leading FGFR4 inhibitor for the treatment of HCC patients with hyper-activation of FGF19/FGFR4 pathway. As of today, no FGFR4 inhibitors have been approved in the world.

Abbisko Therapeutics is also conducting a Phase II trial of Irpagratinib in combination with the anti-PD-L1 antibody, Atezolizumab, produced by F. Hoffmann-La Roche Ltd. and Roche China Holding Ltd. (“Roche”) in late-stage HCC patients with FGF19 overexpression in China's mainland. Patient enrollment is ongoing.

In November 2022, ABSK-011 was given the generic name “Irpagratinib” by the World Health Organization under the International Nonproprietary Name system.

About ABSK043

ABSK043 is a novel, orally administered small molecule PD-L1 inhibitor, displaying exceptional activity and high selectivity. Tumor cells can exploit immune checkpoints such as PD-1 and its ligand PD-L1 to evade immune detection and clearance, thereby suppressing or restricting T-cell responses. While several PD-1/PD-L1 monoclonal antibodies have been approved worldwide, there are currently no approved PD-1/PD-L1 small molecule drugs. ABSK043 selectively binds to the PD-L1 receptor and induces its internalization from the cell surface, effectively inhibiting the interaction of PD-1/PD-L1 and alleviating PD-L1-mediated suppression of T-cell activation. In several preclinical models, ABSK043 has demonstrated anti-tumor efficacy comparable to approved PD-L1 antibody drugs. At present, ABSK043 is undergoing Phase I clinical trial targeting solid tumors in Australia and China.