BridgeBio’s BBO-8520 is a selective, covalent KRAS(G12C) inhibitor which differentiates itself from the pack by engaging the (ON) state of the protein, potentially conferring increased clinical benefit in KRAS(G12C)-driven cancers, including overcoming resistance to current treatments. Disclosed at the 2024 AACR Annual Meeting in San Diego, is currently in a Ph. I trial in patients with advanced non-small-cell lung cancer. This article covers the structure, mechanism of action and preclinical efficacy that marks this compound out as one to watch.

Recently, a surge of (pre)clinical compounds inhibiting the NLRP3 inflammasome, often featuring a hexahydroindacene ring system, has emerged, including Nodthera’s ND-0796. In a push for new chemotypes, AZ and Mitsubishi Tanabe have disclosed their clinical compound, AZD4144, which is currently in Ph. I trials in healthy volunteers. The discovery story detailed their efforts to overcome PLD (phospholipidosis), genotoxicity, and hERG inhibition in a non-classical pharmacophore series. The discovery was presented by Anders Johansson at the EFMC-ISMC 2024 Meeting in Rome.

CDI (Clostridioides difficile) infection is a leading cause of healthcare-associated diarrhea with significant morbidity and mortality, and with the rise of hypervirulent and resistant strains, novel and selective antibiotics to treat these infections are needed. Cadazolid, a hybrid antibiotic that combines pharmacophores of two classes of antibacterials, demonstrated potent activity in vitro against relevant C. difficile strains, while avoiding native gut flora. Additionally, the compound was designed to be gut-restricted, with minimal systemic circulation following PO dosing.

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.

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.