AZD5991

AZD5991 is a potent and direct inhibitor of Mcl-1 with high selectivity versus other Bcl-2 family proteins. AZD5991 binds directly to Mcl-1 and induces rapid apoptosis in cancer cells, most notably myeloma and acute myeloid leukemia (GI50 < 100nM), by activating the Bak-dependent mitochondrial apoptotic pathway. In a panel of cancer-derived cell lines of hematological or solid tumor origin, AZD5991 preferentially kills hematological cells^[1][3].

MOLP-8 cells are treated with AZD5991 or DMSO ontrol for 30 min. Then samples are centrifuged and pellet resuspended in ice-cold lysis buffer and incubated for 20 min on ice with vortexing every 5 min. Next, samples are centrifuged and protein concentration was assessed. Samples are pre-cleared for 30 min using rotation at 4 °C with 50% slurry of Protein A/G magnetic beads followed by incubation with anti-Mcl-1 antibody overnight at 4 °C with rotation. Protein A/G magnetic beads are then added for 1 h at 4 °C with rotation. Beads are washed four times with lysis buffer / PBS (1:1), then 10% sample reducing agent is added to each IP pellet followed by western blotting analysis.

AZD5991 shows potent antitumor activity in vivo with complete tumor regression in several models of multiple myeloma and acute myeloid leukemia after a single tolerated dose as monotherapy or in combination with venetoclax. In these in vivo studies, the cytotoxic activity of AZD5991 tightly correlates with induction of the mitochondrial apoptotic pathway as evidenced by cleavage of caspase-3 and PARP^[1].