17BetaHSD Type 5 Inhibitor

To provide a novel and excellent method for treating and/or preventing prostatic cancer, benign prostatic hyperplasia, acne, seborrhea, hirsutism, baldness, alopecia, precocious puberty, adrenal hypertrophy, polycystic ovary syndrome, breast cancer, lung cancer, endometriosis, leiomyoma and the like based on selective inhibitory activity against 17 HSD type 5. It was found that an N-sulfonylindole derivative, where the indole ring is substituted by a carboxy group, a carboxy-substituted lower alkyl group or a carboxy-substituted lower alkenyl group at its carbon atom, has potent selective inhibitory activity against 17 HSD type 5 and may become a therapeutic agent and/or preventive agent for benign prostatic hyperplasia, prostatic cancer and the like without accompanying adverse drug reactions due to a decrease in testosterone, and the present invention has thus been completed.