PLX-4545 is an oral CRBN-based molecular glue degrader of IKZF2 in Ph. I trials. It potentially addresses anti-tumor immunity suppression within the TME, critical in checkpoint blocker resistance. Tumors use IKZF2 to regulate the function of regulatory T cells and inhibit effector T cells. IKZF2 depletion in regulatory T cells enhances the anti-tumor response. The discovery and structural data of PLX-4545 were presented by Kevin Freeman-Cook at the ACS Fall 2024 First-Time Disclosures session in Denver, CO. We are reporting the discovery story and its potential impact on immuno-oncology.

Novartis’ HRO761 is an oral allosteric WRN helicase inhibitor, aimed at treating MSI-high and dMMR tumors. This article details the discovery of HRO761 and highlights the importance of selecting appropriate assays during early HTS as well as transferable medicinal chemistry strategies to optimize permeability and solubility through the modulation of LipE, neutral TPSA, chameleonicity, and non-classical zwitterions. It also explores the X-ray structure of HRO761 bound to WRN, how it differentiates from Vividion's VVD-214, its preclinical activity, clinical status, chemical synthesis, and more!

Pfizer’s oral, CDK4-selective inhibitor PF-07220060 has the potential to revolutionize treatment of HR+/HER2- breast cancer through avoiding the neutropenia DLTs associated with SoC CDK4/6 drugs and permitting greater coverage of the desired CDK4 target. Our full article outlines data presented at AACR 2024, covering the molecule’s course from in silico-informed screen, through structurally enabled optimization against CDK6 and GSK-3β to promising preclinical profile. Fresh clinical data showed efficacy and tolerability supporting PF-07220060's clinical progression.

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.

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.