This invention relates to a neoadjuvant therapy for bladder cancer in bladder cancer patients who are scheduled for a cystectomy and methods of carrying out such a neoadjuvant therapy. In particular the invention relates to a composition comprising hexyl 5-ALA ester (HAL) or a pharmaceutically acceptable salt thereof for use in a neoadjuvant therapy for bladder cancer in a bladder cancer patient who is scheduled for a cystectomy, the therapy comprises instilling said composition into the bladder of said patient and exposing the inside of said bladder to light.