A drug used to treat recurrent ovarian epithelial, fallopian tube, or primary peritoneal cancer that has gotten better after treatment with anticancer drugs that included platinum. It is used to help keep the cancer from coming back again. Rucaparib camsylate is also used in patients whose cancer has certain mutations (changes) in the BRCA1 or BRCA2 genes and who have already been treated with at least two other types of anticancer drugs. It is also being studied in the treatment of other types of cancer. Rucaparib camsylate blocks an enzyme involved in many cell functions, including the repair of DNA damage. Blocking this enzyme may help keep cancer cells from growing and may kill them. Rucaparib camsylate is a type of poly (ADP-ribose) polymerase inhibitor. Also called AG014699, PARP-1 inhibitor AG014699, and Rubraca.