Therapeutic Targeting of ATR Yields Durable Regressions in Small Cell Lung Cancers with High Replication Stress

Using chemical genetic screens, scientists identified inhibition of ataxia telangiectasia and rad3 related (ATR), the primary activator of the replication stress response, and topoisomerase I (TOP1), nuclear enzyme that suppressed genomic instability, as synergistically cytotoxic in small cell lung cancer (SCLC).