RLY-2608 is an oral, mutant-selective PI3Kα allosteric inhibitor from Relay Therapeutics. Current FDA-approved PI3Kα modulator (alpelisib) and a clinically advanced molecule (inavolisib) are limited by their off-target toxicities associated with the inhibition of WT PI3Kα, leading to hyperglycemia and rash. RLY-2608 is currently in a Ph. I as a single agent and in combination with fulvestrant for HR+/HER2- breast cancer treatment. This article reviews the discovery of RLY-2608, its mechanism of mutant selectivity, how it compares to other molecules, recent clinical developments, and more.

BAY 2925976 is a novel oral ARα2C antagonist developed by Bayer for the treatment of OSA (obstructive sleep apnea), a widespread condition affecting nearly one billion people globally. Despite the availability of mechanical treatments like CPAP, poor adherence rates highlight the need for more effective interventions. BAY 2925976 demonstrated a preclinical proof of concept for ARα₂C modulation as a potential therapeutic approach for OSA. In this article, we detail the discovery of BAY 2925976, as highlighted by Michael Hahn at the ACS Fall 2024 First-Time Disclosures session in Denver, CO.

Genentech announced that fenebrutinib (GDC-0853), a non-covalent BTK inhibitor entering Ph. III, showed significant human CNS exposure and reduced new brain lesions in Ph. II for relapsing multiple sclerosis. Fenebrutinib is the only reversible BTK inhibitor in Ph. III for MS, and has the opportunity to differentiate on safety relative to covalent inhibitors. This case study highlights notable challenges overcome in the discovery of fenebrutinib including surprising metabolism, animal-specific on-target toxicity, and more.

KEAP1 inhibition/NRF2 activation has been hotly pursued in recent years for immunology indications; however, in oncology, NRF2 degradation has been posited as a novel therapeutic mechanism for specific cancers. Vividion has already disclosed work on covalent KEAP1 inhibitors, but at the recent ACS Fall 2024 meeting, the structure and discovery story of their clinical oral covalent activator of KEAP1 were disclosed, identified through careful analysis of the data from their inhibitor screen.

Sonrotoclax, BeiGene’s clinical-stage, orally bioavailable, next-generation inhibitor, targets both WT and mutated forms of the Bcl-2 protein by binding within a hydrophobic groove, similar to other inhibitors in its class. Explore this case study to see how sonrotoclax was rationally designed to potency against both WT and mutant Bcl-2 and address the limitations of first-generation inhibitors and more!