Inavolisib is a PI3Kα isoform-selective kinase inhibitor and monovalent degrader of the mutant p110α catalytic subunit of mutant PI3Kα. The molecule selectively depletes mutant p110α in cancer cells with active RTK (receptor tyrosine kinase) signaling and is in several ongoing or planned Ph. III trials for breast cancer. In October 2024, it received FDA approval for use in combination with palbociclib and fulvestrant to treat adults with endocrine-resistant, PIK3CA-mutated, HR+/HER2- breast cancer. This article explains how it works, how it was discovered, and why it matters.

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.

NDI-101150 is an oral HPK1 inhibitor discovered by Nimbus Therapeutics and is currently in Ph. I/II clinical trial in advanced solid tumors. HPK1 is a compelling immuno-oncology target due to its critical role in regulating T-cells, B-cells, and dendritic cell-mediated immune responses. HPK1-deficient mice demonstrate enhanced anti-tumor T-cell responses and resistance to tumor growth. In this article, we detail the discovery of NDI-101150, as highlighted by Nimbus at the ACS Fall 2024 First-Time Disclosures session, interim results from the clinic, and more.

BMS-986408 is an oral, dual DGK ⍺ and ζ inhibitor currently in a Ph. I/II trial in patients with solid tumors. The compound was identified stemming from a phenotypic screening approach, and subsequent target deconvolution revealed DGK to be the target. If approved, it would be a first-in-class intracellular checkpoint inhibitor of DGK. This is an excellent case study on how to overcome a DILI risk associated with BSEP inhibition, as well as how to improve solubility and PK properties of your compounds through the introduction of polarity, reduction of aromatic rings, and increase in f(sp3).