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.

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

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?

Nested Therapeutics’ lead asset, NST-628, is an oral, brain-penetrant pan-RAF–MEK non-degrading molecular glue that lacks paradoxical pathway activation. Read the full article to learn about NST-628’s fascinating mechanism of action preventing paradoxical pathway activation, how it differentiates from other RAS/RAF/MAPK pathway inhibitors, the likely molecular origin, preclinical profile supporting clinical development, why this might be an ideal combination partner, and why this molecule is a big deal.

BMS-986365 is a potential best-in-class heterobifunctional ligand-directed degrader of WT AR. This full case study details how this heterobifunctional degrader was engineered to have low intrinsic agonism and exert direct antagonism of WT AR through occupancy of its ligand-binding domain, how the dual modality of BMS-986365 results in deep AR pathway inhibition and allows antagonism to reinforce degradation to combat compensatory resistance mechanisms, its attractive preclinical profile, interim clinical data, how it differentiates from Arvinas’ first-to-clinic AR degraders, and more!