As the “Guardian of the Genome,” the tumor suppressor transcription factor p53 has been a much sought-after target in oncology, with over 50% of malignancies showing mutations in p53. The p53(Y220C) mutant has been of particular interest as it creates a pocket which small molecule stabilizers are able to bind to and restore p53 function. PMV Pharma is the first to enter the clinic with their p53(Y220C) stabilizer rezatapopt, which was optimized from a hybrid of known binders and which is showing real promise against a swath of solid tumors.

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.

IAG933 is Novartis’ potential first-in-class small molecule inhibitor of the PPI between YAP/TAZ and TEAD, currently in a Ph. I trial for solid tumors with Hippo pathway alterations. This case study not only highlights a fascinating mechanism of action but also serves as an excellent example of how to leverage structural data to inform hit selection and guide lead optimization, how to employ multiparameter optimization to circumvent cardiotoxicity liabilities, and how to redirect metabolism.

RLY-2608 is an oral, mutant-selective PI3Kα allosteric inhibitor from Relay Therapeutics. Current FDA-approved PI3Kα modulator (alpelisib) and a clinically advanced molecule (inavolisib) are limited by their off-target toxicities associated with the inhibition of WT PI3Kα, leading to hyperglycemia and rash. RLY-2608 is currently in a Ph. I as a single agent and in combination with fulvestrant for HR+/HER2- breast cancer treatment. This article reviews the discovery of RLY-2608, its mechanism of mutant selectivity, how it compares to other molecules, recent clinical developments, and more.

Morphic Therapeutic’s MORF-627 is an oral αvβ6 integrin inhibitor designed to treat IPF by blocking the TGFβ pathway. The Morphic team leveraged SBDD and FEP+ during lead optimization to enhance permeability and isoform selectivity. This article highlights the team’s focus on inhibiting the “bent-closed” conformation of αvβ6 as well as the linker design that led to the “chameloenicity” of the lead compound. The impressive multispecies PK and in vivo efficacy of MORF-627 in preclinical models was unfortunately accompanied by oncogenic toxicity that prevented it from reaching clinical trials.