STX-478 is a wild-type-sparing, oral, CNS-penetrant, novel allosteric inhibitor of mutant PI3Kα (phosphatidylinositol-3 kinase α) 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.

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.

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.

AbbVie’s ABBV-467 is a highly potent, selective MCL-1 (myeloid cell leukemia-1) inhibitor which entered the clinic in 2022 in a Ph. I trial in patients with advanced hematologic cancers. MCL-1 has had a rough time in the clinic with multiple trials being halted or terminated due to cardiac toxicity, which is suspected to be an on-target effect. AbbVie’s approach with ABBV-467 was to target a highly potent/short half-life compound which could induce rapid apoptosis and tumor regressions in a short exposure period before the onset of any adverse events. Is this the end for MCL-1?

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).