Medivation and partner Pfizer are discontinuing development of dimebon (latrepirdine) for the treatment of Huntington disease due to its failure to show benefits in the Phase III Horizon trial. The Horizon trial found dimebon therapy had no beneficial effects in terms of either the mini-mental state examination (MMSE), which measures cognition, or the clinician’s interview-based impression of change plus caregiver input (CIBIC-plus) assessment, which measures global function. An ongoing open-label extension study will also be stopped.
Medivation and Pfizer are separately evaluating dimebon in a Phase III Concert study in Alzheimer disease patients and an associated open-label extension study. Topline data from Concert are expected during the first half of 2012.
Medivation teamed up with Pfizer to develop dimebon for the treatment of Alzheimer disease and Huntington disease back in 2008. Medivation received an up-front cash payment of $225 million and potentially another $500 million in development and regulatory milestones.