The late reports have flooded in since the death of a teenager undergoing gene therapy last year. This prompted the NIH to send stern letters to researchers reminding them of their duty to report problems. One prominent US researcher said he was worried that poor results were being kept secret because of the financial damage they could cause to the funding companies.
Gene therapy is an experimental treatment for serious diseases including cancer.
DNA is inserted into the patient's cell, usually through the action of an infectious virus. Despite much research effort, no successful gene therapy treatment has yet been developed. The newly-revealed failures, detailed in the Washington Post newspaper, show that many patients suffered fevers, clotting abnormalities and serious drops in blood pressure. Problems were also caused by the medical procedures used to deliver the genetic material. Needle damage in patients being treated for brain tumours has apparently led to partial paralysis and speech impairment.