An experimental cancer drug designed to cut off the blood supply that feeds tumours has shown promise in a small-scale trial on human volunteers, a study published online today says.The drug blocks an enzyme involved in the processing of nitric oxide, a chemical that helps maintain the tumour’s blood supply, thus enabling cancer cells to grow and divide.Doctors in London recruited seven women and 11 men in the test, a so-called Phase One trial under the lengthy three-phase process for assessing a new drug for safety and effectiveness.Twelve had lung cancer, five prostate cancer and one had cervical cancer.In eight patients who were given higher doses of the drug, L-NNA, scans showed that the blood volume in their tumours dropped sharply an hour after treatment, a fall that was maintained 24 hours later.As for side effects, three patients suffered from hypertension and three had palpitations or an excessive heartbeat rate.L-NNA stands for N-nitro-L-arginine, the enzyme that the blocker targets.The researchers, led by Quan-Sing Ng of the Mount Vernon Cancer Centre, say the “exciting” results warrant putting L-NNA through further trials. The paper is published by The Lancet Oncology journal.
