This study is being done to determine if the study drug, Olaparib has an effect on urothelial carcinoma or other non-prostate genitourinary cancers in people with DNA-repair changes in their genes.

This study aims to determine if Olaparib is better or worse than the usual approach for urothelial cancer or other non-prostate genitourinary cancers. There is no standard of care for these cancers, but people who are not participating in a study are usually treated with single-drug taxane chemotherapies (e.g. paclitaxel, abraxane, docetaxel).

Olaparib is approved by the U.S. Food and Drug Administration (FDA) and is taken orally.

Participants will receive Olaparib continuously for as long as they respond to the study drug.