Structure-guided design of a selective BCL-XL inhibitor

Abstract

The prosurvival BCL-2 family protein BCL-XL is often overexpressed in solid tumors and renders malignant tumor cells resistant to anticancer therapeutics. Enhancing apoptotic responses by inhibiting BCL-X L will most likely have widespread utility in cancer treatment and, instead of inhibiting multiple prosurvival BCL-2 family members, a BCL-X L -selective inhibitor would be expected to minimize the toxicity to normal tissues. We describe the use of a high-throughput screen to discover a new series of small molecules targeting BCL-XL and their structure-guided development by medicinal chemistry. The optimized compound, WEHI-539 (7), has high affinity (subnanomolar) and selectivity for BCL-X ..