Alzheimer’s drug Dimedon from Pfizer and Medication fails in crucial clinical study

Dimebon (latrepirdine) an investigational drug to treat Alzheimer’s disease failed in late phase clinical studies, Pfizer Inc and Medivation, Inc, the developers of the drug which was thought to be promising lead, announced.

Two Phase 3 trials (the CONNECTION study) data of dimebon (latrepirdine) showed that the drug did not meet its co-primary or secondary efficacy endpoints.

CONNECTION is a Phase 3, multi-national, double-blind, placebo-controlled safety and efficacy trial involving 598 patients with mild-to-moderate AD at 63 sites in North America, Europe, and South America.

Patients had a mean age of 74.4 years. More than 40 percent of the patients enrolled were in the United States.

Dimedon showed no statistically significant improvements for the 20 mg relative to placebo on cognition.

The 20 mg dimebon-treated patients also showed no statistically significant differences compared to placebo on the secondary efficacy endpoints.

Dimebon (latrepirdine) is an investigational oral medication being tested as a potential treatment for Alzheimer’s disease and Huntington disease.

Dimebon has a unique mechanism of action, distinct from currently available treatments. In preclinical studies, dimebon has been shown to protect brain cells from damage and enhance brain survival, potentially stabilising and improving mitochondrial function.

Mitochondria are critical to brain cell functioning as they are the primary source of energy for cells. Drugs that protect mitochondria or restore their function could potentially be a valuable treatment approach in AD.

Dimebon is being studied in four other ongoing randomized, double-blind, placebo-controlled Phase 3 studies, which currently are enrolling.

The CONCERT trial is a 12-month study testing dimebon in patients with mild-to-moderate Alzheimer’s disease who are taking donepezil, a commonly prescribed Alzheimer’s disease medication.

Glasgow Memory Clinic was conducting the CONCERT trial , a one-year international study set up to test the effectiveness, dimebon (latrepirdine), in patients currently taking Aricept (donepezil HCI tablets), the leading medication for Alzheimer’s disease worldwide.

More than 1,000 patients from across western Europe, the United States, Australia and New Zealand were expected to take part in the CONCERT trial and it is hoped that the combined medication will help stabilise the condition of those with Alzheimer’s by safely improving cognition (thinking and awareness), memory, daily functioning, behaviour and the ability to care for oneself.

CONCERT is an important study because dimebon is thought to work differently to current medications and this study will evaluate whether adding it to one of the most commonly used Alzheimer’s medications will provide a more effective symptomatic treatment to patients, stabilising their condition and ultimately improving their quality of life.

The CONTACT and CONSTELLATION trials are six-month trials testing dimebon in patients with moderate-to-severe Alzheimer’s disease taking currently approved AD medications.

In CONTACT, patients must also be taking donepezil, while in CONSTELLATION they must also be taking memantine, another commonly prescribed Alzheimer’s disease medication.

Dimebon is also being tested in the HORIZON trial, a six-month study evaluating dimebon in patients with Huntington disease.

The results from the CONNECTION study are unexpected, stated Dr. David Hung, president and chief executive officer of Medivation.

Alzheimer’s disease is a progressive degenerative brain disorder. The disease gradually destroys a person’s memory and ability to learn, reason, make judgments, communicate and carry out daily activities.

As the disease progresses, patients may experience changes in personality and behavior, such as delusions, hallucinations, anxiety and agitation.

Medivation and Pfizer have a global collaboration to develop and commercialize dimebon for the treatment of Alzheimer’s disease and Huntington disease. Under the terms of the agreement, the companies work together on the Dimebon development program.