Radiation is used to either destroy tumors completely or to shrink them prior to surgical removal. Previous research had led to a promising compound called Idoxuridine (IUdR) which had been shown to significantly improve the effectiveness of radiotherapy. The drug however, could only be given intravenously (IV) and had many side effects for patients.
As a result of more recent research, a prodrug called IPdR has been developed. It is called a prodrug because by itself it has little or no pharmacological efficacy. It does however, allow for greater absorption into the body and once in the blood stream, metabolic enzymes oxidize IPdR into IUdR. It was discovered that a dose of 1200 mg per day of IPdR led to optimal blood levels of IUdR with minimal side effects and the prodrug can be taken in capsules instead of IV.
In one clinical study IPdR was administered to 18 patients with various advanced cancers including cancers of the esophagus, pancreas, liver and colon. The patients were administered IPdR for 28 days.
The researchers evaluated the tumors of 14 of the cancer patients 54 days later. CT and MRI scans revealed that the tumors disappeared altogether in one person, shrunk by 30% in three people and stagnated in nine others.