Abbisko Therapeutics Co. Ltd. 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)ann annual meeting to be held in Spain, from October 20 to 24, 2023. The Irpagratinib BID cohorts demonstrated a promising antitumor activity with an ORR of 40.7% in FGF19+ HCC pts with prior therapies.

Both research results will be the first of such release by a Chinese company for the respective target. Abbisko will present the following posters at the ESMO conference: First-in-human study of ABSK-011, a novel, highly selective fibroblast growth factor receptor (FGFR) 4 inhibitor for treating advanced hepatocellular carcinoma (HCC) with FGF19 overexpression. Background: FGF19 overexpression (+) is in ~ 30% of HCC with poor prognosis.

FGF19/FGFR4 signaling axis could be a therapeutic target for HCC2. ABSK-011 is an oral, highly selective, and potent FGFR4 inhibitor for treating FGF19+ HCC. conclusion: ABSK-011 was well-tolerated in HCC pts.

BID cohorts demonstrated a promising anti-tumor activity with anORR of 40.7% In FGF19+ HCC patients with prior therapies, which suggests that ABSK-011 may have clinical benefit through biomarker selection of FGF19. The study is still ongoing, and the efficacy of BID cohorts warrants further investigation. First-in-human dose-escalating study of ABSK043, a novel and oral small-molecule inhibitor of PD-L1, in patients with advanced solid tumors.

Immunotherapies targeting the PD-1/PD-L1 pathway with therapeutic antibodies have shown remarkable anti-tumor effects. ABSK043 is an oral small molecule PD-L1 inhibitor that potently blocks PD-1/PD- L1 interaction. Comparing to antibodies, small molecules render lower immunogenic risk and convenience in administration.

Here, the preliminary results from the dose escalation part of first-in-human (FIH) study of ABSK043 in patients with advanced solid tumors (NCT04964375). Results: ABSK043 was well tolerated up to 1000 mg BID with no DLT reported and has a safety profile consistent with monoclonal antibody immune checkpoint inhibitors. On-target PD effects were consistent with PD-L1 inhibition and data reported by anti-PD-(L)1 mAbs.

Preliminary anti-tumor activity was observed, and further investigation is warranted to explore the efficacy in a larger number of patients.