Chiesi Farmaceutici’s CHF-6523 is an inhaled, lung-restricted, selective PI3Kδ inhibitor designed to provide relief to patients with COPD. Its development involved optimization of permeability and solubility as well as identification of a solid form amenable for dry powder inhalation. Disclosed at the EFMC-ISMC 2024 joint conference in Rome, Italy, this article covers the structure, development, and early clinical data of CHF-6523, which ultimately indicates that PI3Kδ inhibition may not provide clinical effect in reduction of lung inflammation.

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.

BAY 2413555 is a M2R PAM that has the potential to counter parasympathetic withdrawal and restore autonomic balance in heart failure patients. The preclinical and clinical data of BAY 2413555 showed it has positive effects on heart rate and heart rate variability and a relatively long human t1/2 of 37 h. The Ph. I trial, however, was terminated in March 2024 due to findings from a chronic toxicology study. This article covers the discovery of BAY 2413555, presented by Alexandros Vakalopoulos of Bayer at the EFMC-ISMC 2024 conference in Rome and published in the Journal of Medicinal Chemistry.

Sovleplenib (HMPL-523) is an orally bioavailable Syk inhibitor being developed by HUTCHMED and is currently in Ph. II and Ph. III clinical trials for several autoimmune diseases. Derived from an HTS hit and SAR optimization, the discovery story of sovleplenib serves as an excellent case study on how to design a next-generation Syk inhibitor devoid of off-target kinase activity, mitigated hERG activity, 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.