GenFleet Therapeutics, a clinical-stage biotechnology company focusing on cutting-edge therapies in oncology and immunology, announced that the first patient has been dosed in a Phase 1/2 trial in China, conducted by GenFleet Therapeutics, evaluating GFH375/VS-7375, a KRAS G12D (ON/OFF) inhibitor.
GFH375 was selected as Verastem’s lead discovery program from its collaboration with GenFleet established in 2023. GFH375/VS-7375 is an oral, potent and selective KRAS G12D dual inhibitor of ON (GTP) and OFF (GDP) states. Preclinical data presented at the American Association for Cancer Research (AACR) Annual Meeting in April 2024 demonstrated oral bioavailability across preclinical species, strong anti-tumor activity as a single agent and potency against intracranial tumor models suggesting the potential to treat brain metastases.
The Phase 1 study is being conducted in approximately 20 hospitals currently in China and will evaluate the safety and efficacy of GFH375 in patients with advanced KRAS G12D mutant solid tumors. The Phase 1 study will determine the recommended Phase 2 dose (RP2D) and then further evaluate in Phase 2 the efficacy and safety of GFH375 in patients with advanced solid tumors, such as pancreatic ductal adenocarcinoma, colorectal cancer and non-small cell lung cancer.
About KRAS G12D Mutation and GFH375
RAS proteins, in active GTP-bound or inactive GDP-bound form, are binary molecular switches controlling cellular responses in signaling pathways including RAS-RAF-MEK-ERK and PI3K/AKT/mTOR. Three RAS genes encode for protein isoforms, namely Kirsten Ras (KRAS), Harvey Ras (HRAS) and Neuroblastoma Ras (NRAS), and KRAS is the most frequently mutated oncogene in humans. Among KRAS mutations, G12D, G12V, and G12C represent the top three most frequently mutated alleles. KRAS G12D mutation is commonly found in pancreatic ductal adenocarcinoma, colorectal cancer, and lung adenocarcinoma. A large percentage of patients harboring KRAS G12D mutation are found without smoking history and with poor response to PD-1 inhibitors. Mutant-selective G12D inhibitors hold promise to benefit large segments of KRAS-driven PDAC patients since KRAS G12D alterations are the most frequently occurring somatic change in PDAC patients (about 40%) who are reported to have an overall 5-year survival rate lower than 10%.
GFH375 is an orally active, potent, highly selective small-molecule KRAS G12D (ON/OFF) inhibitor designed to target the GTP/GDP exchange, thereby disrupting the activation of downstream pathways and effectively inhibiting tumor cell proliferation. Preclinical studies demonstrated that the inhibition of GFH375 on tumor growth is enhanced along with the increase in dosage and duration of treatment; GFH375 also demonstrated low off-target risk in kinase selectivity and safety target assays.
GenFleet entered into a discovery and development collaboration with Verastem Oncology (Nasdaq: VSTM) to advance three novel oncology discovery programs related to RAS pathway-driven cancers. The risk-sharing structure of the collaboration provides Verastem Oncology a milestone-based option to license up to three compounds. The licenses would give Verastem Oncology development and commercialization rights outside of China while GenFleet would retain rights inside of the Chinese mainland, Hong Kong, Macau, and Taiwan.
