Another second-generation selective CDK9 inhibitor, voruciclib, was demonstrated to downregulate Mcl-1 expression in AML cells and synergize with venetoclax both in vitro and in mouse xenograft models, demonstrating promising potential as a combinational therapy.109 A phase I escalation study is currently recruiting patients with B cell malignancies and AML to determine the safety and preliminary efficacy of voruciclib after treatment with standard therapy (NCT03547115). Here, CDK9 is linked to acute myeloid leukemia.