A combination of two drugs used to treat colorectal cancer that has spread to other parts of the body and has already been treated with other anticancer drugs. It is also being studied in the treatment of other types of cancer. It is a combination of trifluridine and tipiracil hydrochloride. Lonsurf stops cells from making DNA, which may help keep cancer cells from growing and may kill them. Also called trifluridine and tipiracil hydrochloride.