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.

Inavolisib is a PI3Kα isoform-selective kinase inhibitor and monovalent degrader of the mutant p110α catalytic subunit of mutant PI3Kα. The molecule selectively depletes mutant p110α in cancer cells with active RTK (receptor tyrosine kinase) signaling and is in several ongoing or planned Ph. III trials for breast cancer. In October 2024, it received FDA approval for use in combination with palbociclib and fulvestrant to treat adults with endocrine-resistant, PIK3CA-mutated, HR+/HER2- breast cancer. This article explains how it works, how it was discovered, and why it matters.

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!

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.

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.