A controversial late phase trial on an experimental treatment for Alzheimer’s disease ended in unexpected failure, leaving San Francisco’s Medivation, looking for answers and physicians, patients, and family members of people with Alzheimer’s hoping a new treatment will emerge.

As there have been no new Alzheimer’s drugs approved for market since 2003, the trial for Dimebon was closely followed. Medivation, and its partner Pfizer, were looking to show, in this almost 600 patient trial, that the pharmaceutical improved thinking skills in patients with mild to moderate Alzheimer’s. Results, however, showed little difference from placebo results.

An earlier Phase II study done entirely in Russia had showed improvements in the cognitive skills of patients with Alzheimer’s, sparking hope that this multinational Phase III trial would be successful.