WASHINGTON: Two US drug firms say they will stop development of an Alzheimer's drug because it failed in two late-stage clinical trials. Bapineuzumab, made by Pfizer and Johnson & Johnson, was designed to halt build-up of plaque in the brain. But it failed to improve cognitive or functional performance compared with a placebo in certain patients. Both firms announced on 23 July that the first clinical trial of the intravenous (IV) version of bapineuzumab had failed. In that study, patients with a gene that is associated with a greater risk of Alzheimer's were tested. But results with the group were largely the same as with those who did not have the gene, who were tested in the second study. The second trial's end means that additional studies on the IV version will not take place; however, Johnson and Johnson said a study of subcutaneous use would continue. A similar drug being developed by Eli Lilly, solanezumab, is also considered a long-shot to succeed, but results of the trials will not be available until later this year.