Boehringer refocuses PDE9 inhibition brain research after AD disappointment

The latest to join the ranks of failure in the search for a meaningful treatment for Alzheimer’s disease is Boehringer Ingelheim, which today announced that its Phase II Alzheimer’s disease trials with investigational compound BI 409306 had not met their efficacy endpoints.

The German family-owned pharma major says that, as a result, plans for further trials with BI 409306, a potent and selective phosphodiesterase E9A (PDE9A) inhibitor, in AD will therefore not be pursued. Instead, the company will refocus efforts on the ongoing schizophrenia trials with this compound.

These Alzheimer’s disease trials were part of an extensive clinical trial program exploring the efficacy of compounds which target malfunctioning of specific (glutamatergic) brain circuits as potential new treatments for specific symptoms and traits of a mental illness. As such, the investigational compound BI 409306 was explored in patients with cognitive impairment and those with memory dysfunction in schizophrenia and in Alzheimer’s disease. Further investigations will focus on two studies in schizophrenia, aimed at prevention of relapse and at prevention of occurrence of a first psychotic episode.