molecules of the month

The Genentech PI3Kα isoform-selective kinase inhibitor and mutant PI3Kα degrader inavolisib selectively depletes the oncogenic mutant p110α catalytic subunit of PI3Kα in cancer cells with active receptor tyrosine kinase (RTK) signaling. The gene encoding p110α, PIK3CA, is one of the most frequently mutated oncogenes, with over 2M cancer patients diagnosed annually with PIK3CA-mutant tumors. PI3Kα has been a target of significant interest for many years, but it has been challenging to identify drugs with significant benefit due to the toxicities associated with wild-type PI3K-family inhibition and negative feedback triggered by PI3K inhibition that activates RTK signaling, counteracting drug activity. By being highly selective for PI3Kα and selectively degrading mutant p110α by a mechanism that appears to depend on RTK activation,…