9bgb
Tri-complex of Daraxonrasib (RMC-6236), KRAS Q61H, and CypA
Structural highlights
DiseaseRASK_HUMAN Defects in KRAS are a cause of acute myelogenous leukemia (AML) [MIM:601626. AML is a malignant disease in which hematopoietic precursors are arrested in an early stage of development.[1] Defects in KRAS are a cause of juvenile myelomonocytic leukemia (JMML) [MIM:607785. JMML is a pediatric myelodysplastic syndrome that constitutes approximately 30% of childhood cases of myelodysplastic syndrome (MDS) and 2% of leukemia. It is characterized by leukocytosis with tissue infiltration and in vitro hypersensitivity of myeloid progenitors to granulocyte-macrophage colony stimulating factor. Defects in KRAS are the cause of Noonan syndrome type 3 (NS3) [MIM:609942. Noonan syndrome (NS) [MIM:163950 is a disorder characterized by dysmorphic facial features, short stature, hypertelorism, cardiac anomalies, deafness, motor delay, and a bleeding diathesis. It is a genetically heterogeneous and relatively common syndrome, with an estimated incidence of 1 in 1000-2500 live births. Rarely, NS is associated with juvenile myelomonocytic leukemia (JMML). NS3 inheritance is autosomal dominant.[2] [3] [4] [5] [6] [7] Defects in KRAS are a cause of gastric cancer (GASC) [MIM:613659; also called gastric cancer intestinal or stomach cancer. Gastric cancer is a malignant disease which starts in the stomach, can spread to the esophagus or the small intestine, and can extend through the stomach wall to nearby lymph nodes and organs. It also can metastasize to other parts of the body. The term gastric cancer or gastric carcinoma refers to adenocarcinoma of the stomach that accounts for most of all gastric malignant tumors. Two main histologic types are recognized, diffuse type and intestinal type carcinomas. Diffuse tumors are poorly differentiated infiltrating lesions, resulting in thickening of the stomach. In contrast, intestinal tumors are usually exophytic, often ulcerating, and associated with intestinal metaplasia of the stomach, most often observed in sporadic disease.[8] [9] [10] Note=Defects in KRAS are a cause of pylocytic astrocytoma (PA). Pylocytic astrocytomas are neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors.[11] Defects in KRAS are a cause of cardiofaciocutaneous syndrome (CFC syndrome) [MIM:115150; also known as cardio-facio-cutaneous syndrome. CFC syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. Heart defects include pulmonic stenosis, atrial septal defects and hypertrophic cardiomyopathy. Some affected individuals present with ectodermal abnormalities such as sparse, friable hair, hyperkeratotic skin lesions and a generalized ichthyosis-like condition. Typical facial features are similar to Noonan syndrome. They include high forehead with bitemporal constriction, hypoplastic supraorbital ridges, downslanting palpebral fissures, a depressed nasal bridge, and posteriorly angulated ears with prominent helices. The inheritance of CFC syndrome is autosomal dominant. Note=KRAS mutations are involved in cancer development. FunctionRASK_HUMAN Ras proteins bind GDP/GTP and possess intrinsic GTPase activity. Publication Abstract from PubMedOncogenic RAS mutations are among the most common in human cancers. To target the active, GTP-bound state of RAS(ON) directly, we employed an innovative tri-complex inhibitor (TCI) modality. Formation of a complex with an intracellular chaperone protein CypA, an inhibitor, and a target protein RAS blocks effector binding, inhibiting downstream RAS signaling and tumor cell proliferation. Herein, we describe the structure-guided SAR journey that led to the discovery of daraxonrasib (RMC-6236), a noncovalent, potent tri-complex inhibitor of multiple RAS mutant and wild-type (WT) variants. This orally bioavailable bRo5 macrocyclic molecule occupies a unique composite binding pocket comprising CypA and SWI/SWII regions of RAS(ON). To achieve broad-spectrum RAS isoform activity, we deployed an SAR campaign that focused on interactions with residues conserved between mutants and WT RAS isoforms. Concurrent optimization of potency and drug-like properties led to the discovery of daraxonrasib (RMC-6236), currently in clinical evaluation in RAS mutant advanced solid tumors (NCT05379985; NCT06040541; NCT06162221; NCT06445062; NCT06128551). Discovery of Daraxonrasib (RMC-6236), a Potent and Orally Bioavailable RAS(ON) Multi-selective, Noncovalent Tri-complex Inhibitor for the Treatment of Patients with Multiple RAS-Addicted Cancers.,Cregg J, Edwards AV, Chang S, Lee BJ, Knox JE, Tomlinson ACA, Marquez A, Liu Y, Freilich R, Aay N, Wang Y, Jiang L, Jiang J, Wang Z, Flagella M, Wildes D, Smith JAM, Singh M, Wang Z, Gill AL, Koltun ES J Med Chem. 2025 Mar 8. doi: 10.1021/acs.jmedchem.4c02314. PMID:40056080[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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