31 August 2026, Abbisko Therapeutics Co., Ltd. ("Abbisko Therapeutics" hereafter, HKEX code: 02256.HK) today announced that the first patient has been dosed in the Phase I clinical study evaluating ABSK211, an oral, highly potent small-molecule pan-KRAS inhibitor with broad alteration coverage, for the treatment of patients with advanced solid tumors harboring KRAS alterations.

The ongoing Phase 1 clinical study aims to assess the safety, tolerability, efficacy and pharmacokinetics of ABSK211 in patients with advanced solid tumors harboring KRAS alterations.

KRAS is among the most frequently altered oncogenic driver genes across human cancers and is highly prevalent across multiple solid tumor types, including approximately 90% of pancreatic ductal adenocarcinomas, 45% of colorectal cancers, and 34% of non-small cell lung cancers. Due to the complexity and diversity of KRAS alteration subtypes, KRAS has long been regarded as one of the most challenging targets in oncology. While several programs are in ongoing clinical development, there remains a critical need for molecules with enhanced potency and selectivity.

Preclinical studies demonstrate ABSK211 exhibits broad and potent inhibitory activity across multiple major KRAS alterations, including KRAS G12D, G12C, G12S, G12V, G13D, and KRAS wild-type amplification. In vitro studies show that ABSK211 significantly inhibits proliferation of multiple KRAS-mutant tumor cell lines at sub-nanomolar to nanomolar concentrations, while exhibiting minimal activity in KRAS wild-type cell lines with normal copy numbers. In vivo studies further demonstrate that ABSK211 induces deep and durable tumor regression across multiple KRAS-altered tumor models with robust target engagement.

In addition, ABSK211 demonstrates promising potential in combination therapy settings across multiple tumor models. Preclinical study results show that combining ABSK211 with PRMT5 inhibitors, cetuximab, immunotherapy, and chemotherapy further enhances anti-tumor activity with potential for prolonged durable responses. These findings provide strong rationale to further explore ABSK211-based combination strategies in tumor types with a known prevalence of KRAS alterations, including pancreatic cancer, colorectal cancer, lung cancer, among several other KRAS-driven tumor types.

About ABSK211

ABSK211 is a novel orally bioavailable investigational small molecule pan-KRAS inhibitor independently developed by Abbisko Therapeutics. It is designed to target a broad spectrum of KRAS alterations, including common KRAS mutation subtypes, and select KRAS amplification settings. Preclinical data demonstrate encouraging anti-tumor activity and favorable selectivity of ABSK211 in both monotherapy and combination treatment settings, supporting its potential to provide a new therapeutic option for patients with KRAS-altered solid tumors. ABSK211 has received IND clearance from both the China NMPA and US FDA, and is on track for global clinical development having completed first patient dosing.

About Abbisko Therapeutics

Founded in 2016, Abbisko Therapeutics Co., Ltd. (HKEX: 02256) is a pharmaceutical company committed to the research, discovery, and development of innovative and differentiated medicines designed to address unmet medical needs in China and globally.

Adhering to international concepts and standards for drug development, Abbisko primarily centers on small molecules, emphasizing precision oncology and immuno-oncology, with a growing expansion into both non-oncology therapeutic areas and other modalities. Its self-developed Class 1 innovative drug, pimicotinib, has received approval from the China NMPA, while dozens of other candidates are currently in clinical development stages.

Abbisko is committed to creating first-in-class and best-in-class innovative drugs. Through an unwavering pursuit of scientific innovation, the company strives to provide transformative therapies with breakthrough efficacy for patients worldwide.

Please visit www.abbisko.com for more information.