RMC-6236 is a non-covalent pan-RAS(ON) inhibitor from Revolution Medicines, which shows remarkable efficacy in tumors driven by RAS mutants that were previously considered “undruggable,” such as G12V/D/A/S, G13X, and Q61X. RMC-6236 exerts its action via a “tri-complex” mechanism, gluing RAS to the ubiquitously expressed chaperone protein, cyclophilin A. Our in-depth article covers the presentation given at the AACR 2024 meeting, which outlines the discovery and preclinical profile of RMC-6236 as well as the latest clinical updates.

Nurix Therapeutics’ NX-1607 is the first oral small molecule inhibitor of CBL-B to enter clinical trials. CBL-B negatively regulates immune activation in T, B, and NK cells; while immune checkpoint inhibitors are often effective, they have limitations, including lack of efficacy in certain cancers, patient variability, and resistance. NX-1607 enhances T cell activation by gluing CBL-B in an inactive conformation and, driven by preclincial data, NX-1607 is currently in a Ph. I trial. This article details its discovery story and initial clincial results, presented at the ACS Spring 2024 meeting.

ORIC-533, a potential best-in-class oral inhibitor of CD73 from ORIC Pharmaceuticals, is currently in a Ph. Ib trial for relapsed/refractory multiple myeloma (MM). It inhibits the CD73-mediated conversion of AMP to adenosine which generates an immunosuppressive tumor microenvironment and has the potential to be a next-generation immunotherapy. The in-depth use of X-ray structures led the team to discover a novel set of phosphonate bioisosteres which acheived bioavailability in a polar scaffold. The structure and discovery of ORIC-533 were recently disclosed at the ACS Spring 2024 Meeting.

Deciphera’s DCC-3116 is an oral ULK1/2 inhibitor targeting the autophagy pathway, a key mechanism of tumor survival and resistance to targeted therapy. Currently in two open-label Ph. I/II trials as a monotherapy and in combination with RTK pathway inhibitors, the structure and discovery of this first-in-class compound were recently presented at the ACS Spring 2024 meeting.

STX-478 is a wild-type-sparing, oral, CNS-penetrant, novel allosteric inhibitor of mutant phosphatidylinositol-3 kinase α (PI3Kα), targeting a cryptic pocket near the ATP-binding site. PI3Kα plays a central role in many cancers, and has been recently highlighted in coverage of 2021 Molecule of the Year nominee and PI3Kα degrader inavolisib. Currently approved PI3Kα modulators are limited by their off-target activities on WT PI3Kα and other kinases, leading to significant side effects including hyperglycemia and rash.