Lundbeck Throws In the Towel on Alzheimer’s Drug

Phase 3 results cast doubt on 5-HT6 receptor inhibitors

Denmark’s Lundbeck has stopped working on its investigational Alzheimer’s medication idalopirdine after two phase 3 studies failed to demonstrate clinical efficacy, according to the company’s latest financial report. The drug is the latest in a long line of Alzheimer’s failures over the past several years.

“In September, we communicated that the first clinical phase 3 study investigating idalopirdine for the treatment of Alzheimer’s disease was not successful,” the company reported. “In February 2017, the two remaining studies in the clinical phase 3 programme evaluating the safety and efficacy of idalopirdine were finalized. In line with the results seen in the first study, idalopirdine was safe and well tolerated. The efficacy profiles in all three clinical studies do not, however, demonstrate efficacy as observed in the positive clinical phase 2 study and hence do not suffice to support a regulatory submission.”

The setback casts further doubt on the use of 5-HT6 (serotonin) receptor antagonists in patients with Alzheimer's disease (AD), following the discontinuation by Pfizer of another 5-HT6 antagonist last year.

5-HT6 blockers are designed to promote the release of acetylcholine, a neurotransmitter needed for normal cognition. The idea is to use them in combination with the acetylcholinesterase inhibitor donepezil (Aricept, Eisai/Pfizer) to help patients with mild-to-moderate AD.

Sources: Lundbeck Annual Report; February 8, 2017; and Reuters; February 8, 2017.