Preclinical antitumor efficacy of ETN101, a novel oral anticancer agent with Wnt/ß-catenin signaling inhibition, TME modulation, and VEGFR2 targeting for advanced hepatocellular carcinoma treatment.

Abstract

e16138 Background: Hepatocellular carcinoma (HCC) is an important cancer in worldwide with over 900,000 new cases and approximately 830,000 deaths were reported in 2020. It ranks sixth in global cancer incidence and third in mortality, highlighting its worldwide significance. The high frequency of occurrence and elevated mortality rates contribute to a significant socio-economic burden. However, most patients are diagnosed in the middle and late stages, missing the optimal treatment. Therefore, it is necessary to develop novel, safe, and effective drugs for HCC inhibition, elucidating their mechanisms of action. Methods: Evaluation of ETN101 was utilized in subcutaneous xenograft and orthotopic animal models with human HCC cell lines. ETN101 was administered orally. The tumor volume, tumor weight, and bodyweight were measured, and cancer cell proliferation and apoptosis were also analyzed. The toxicity of ETN101 was investigated through GOT/GPT and histological analysis in the liver and kidney. The signaling mechanism of ETN101 was analyzed through kinase analysis, phosphorylation, in silico docking analysis, and RNA sequencing, both in vitro and in vivo. Results: ETN101 demonstrated approximately 30% tumor inhibition at 10 mg/kg group compared to control. Moreover, 20 mg/kg treatment group also showed significant tumor reduction in all individuals with one complete response (CR). Interestingly, all individuals exhibited CR from 40 to 82 mg/kg treatment groups. During the 10 administrations of Nexavar and Lenvatinib, individuals who showed proliferated tumors persistently were selected, followed by the administration of ETN101. All individuals exhibited either CR or significant reduction in tumor volume upon ETN101. After tracking complete responders for two months, there were no signs of tumor recurrence or metastasis. These results suggested that ETN101 has anticancer effect by regulating Wnt/ß-catenin pathway in tumor microenvironment (TME) with increasing the infiltration of cytotoxic T cells into the tumor. Furthermore, it targets VEGFR2, blocking angiogenesis-related signals to improve therapeutic effects in advanced HCC. Conclusions: Due to lack of effective single drugs for advanced HCC patients, combination therapy is used clinically. We developed ETN101, a monotherapy that targets VEGFR2 and modulates the TME with the same mechanism as the combination therapy. ETN101 also showed excellent efficacy in preclinical study and secured a broad safety margin relative to the effective dose. In addition, ETN101 was effective in those who are not responded to conventional targeted cancer therapies. It is anticipated that ETN101 could serve as a novel therapeutic strategy for advanced HCC patients.