GenFleet Therapeutics, a clinical-stage biotechnology company focusing on cutting-edge therapies in oncology and immunology, announced the latest findings of GFH547, an oral panRAS (ON) inhibitor, in a late-breaking research abstract at the 2024 American Association for Cancer Research (AACR) Annual Meeting.

GFH547 is developed with novel mechanism of action by reshaping and repurposing intracellular cyclophilin A (CypA) protein to target active RAS proteins across most wild/mutant subtypes. Preclinical data demonstrated profound panRAS inhibitory activity of GFH547 and it holds the potential to overcome adaptive and acquired resistance against SIIP (switch II pocket)-based KRAS inhibitors.

"Secondary mutations detected among subjects in clinical studies of KRAS inhibitors have paved the way for the development of future therapies, and GFH547 is anticipated as a new-generation inhibitor to combat the drug resistance. GenFleet's KRAS G12C inhibitor (GFH925) has had its New Drug Application accepted with Priority Review Designation in China. From the first-generation KRAS inhibitor to a new-generation pan-RAS inhibitor, the continuous achievements underscore GenFleet's insight into the development of RAS pathway targeted therapies. The top-tier development also showcases the depth of GenFleet's cutting-edge pipeline and its value potential." stated Fusheng Zhou, Ph.D., Vice President of GenFleet's Drug Discovery Department. 

Abstract Title: GFH547: An orally bioavailable, cyclophilin A-hijacking panRAS (ON) inhibitor with broad spectrum anti-tumor activities

Abstract No.: LB165/11

• The GFH547-Cyp A-RAS tripartite complex inhibits most wild/mutant subtypes of active, GTP-bound RAS proteins

GFH547 has demonstrated preliminary efficacy to inhibit RAS proteins across most subtypes including the KRAS mutant proteins commonly found in human tumors (especially harboring G12C, G12D and G12V mutations). Compared with targeting RAS proteins or the RAS-RAF complex alone, the recruitment of CypA into the tripartite complex induces more profound inhibition of RAS pathway (including the RAS proteins and their downstream interaction with RAF).

The deep inhibition of KRAS pathway was observed following a single oral administration of GFH547 in KRAS mutant CDX tumors. GFH547 also demonstrates dose-dependent anti-tumor activity and drives tumor regression in KRAS mutant tumor models.

• GFH547 is superior to the mainstream SIIP-based KRAS inhibitors in overcoming adaptive and acquired resistance

GFH547 is resistant to RTK activation by EGF stimulation which attenuates potency of current mainstream SIIP-based KRAS inhibitors. It is also effective to cells carrying secondary KRAS mutations causing acquired resistance to SIIP-based KRAS inhibitors. Overall, GFH547 demonstrates promising bioavailability, kinase selectivity and safety in the preclinical research.

About RAS and GFH457

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、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.

GFH547 is a novel small-molecule panRAS (ON) inhibitor hijacking Cyp A to target active, GTP bound RAS proteins of most wild/mutant subtypes, including most commonly found KRAS mutant (G12C, G12D, G12V, etc.) proteins. Preclinical research of GFH547 demonstrates dose-dependent anti-tumor activity and drives tumor regression in multiple KRAS mutant tumor models. GFH547 is also superior to the mainstream SIIP (switch II pocket)-based KRAS inhibitors in overcoming adaptive and acquired resistance.