Halted 2 April 2001. Immune Network Ltd. reported last week that the company's Canadian Phase I clinical study has been halted due to an unexplained incidence of adverse findings in blood samples from healthy volunteers.
Studies are now under way to investigate the cause of the adverse effects.
Previous studies in other countries have not reported such adverse effects and the drug, originally developed to treat leprosy, and dapsone is currently in Phase II trials in a number of countries as a potential therapy for Alzheimer's disease. Researchers became interested in dapsone following reports of a low incidence of Alzheimer's among elderly leprosy patients. The report of adverse effects will not influence the ongoing DAD200 international Phase II trials. See our factsheet on dapsone . Common side effects of the drug are gastrointestinal in nature, with a small percentage of patients experiencing nausea, vomiting, anorexia, diarrhea and weight loss.