Istisociclib (KB-0742, KB0742) is a potent, orally bioavailable, selective CDK9 inhibitor with IC50 of 6 nM (CDK9/cyclin T1 inhibition).
KB-0742 displays >60-fold selectivity over CDK2/12/13, and >200-fold over other CDKs.
KB-0742 rapidly downregulates nascent transcription, preferentially depleting short half-life transcripts and AR-driven oncogenic programs.
Oral administration of KB-0742 significantly reduced tumor growth in CRPC models.
