Arcus Biosciences recently disclosed the structure and discovery story of their oral HIF-2α inhibitor casdatifan (AB521) at the ACS Fall 2024 First Time Disclosures session in Denver. Read on to find out how the team overcame serum shifts and metabolism issues to deliver into the clinic what could potentially be a best-in-class compound, superior to the recently approved inhibitor, belzutifan.

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.

BMS-986397 is a potential first-in-class CRBN-based selective CK1α molecular glue degrader. CK1α promotes tumor growth by enhancing MDM2 and MDMX degradation of the tumor suppressor p53. Since AML has a low TP53 mutation rate, activating the p53 pathway is a promising approach; however, p53 activators have faced challenges due to hematological toxicities. Targeting CK1α degradation offers an alternative approach. The BMS team sought to develop a CELMoD® for CK1α degradation. This article outlines the discovery of BMS-986397, as presented at the ACS Fall 2024 meeting in Denver, CO.

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.

Nuvalent’s lead compound, NVL-520, is an oral, brain-penetrant, TRK-sparing, and potential best-in-class ROS1 kinase inhibitor that recently entered Ph. II of the ARROS-1 trial (NCT05118789) in patients with advanced ROS1-positive NSCLC. This article highlights what makes the Nuvalent’s NVL-520 program scientifically notable, including what gives it a potential best-in-class profile as a ROS1 inhibitor, the emerging toxicology of hard-to-avoid off-targets, an interesting synthetic route to the small macrocycle, and more.