Pfizer Inc. said Wednesday that its Alzheimer's drug candidate Dimebon did not meet its goal in a late stage clinical study, as the drug was no better than a placebo at treating the disease.
The compound Dimebon did not meet any of its main or secondary goals in the study, which involved 598 patients with mild to moderate Alzheimer's disease. Dimebon is considered one of Pfizer's key drug candidates and the company is running four other late stage trials of the drug.
"The results from the CONNECTION study are unexpected, and we are disappointed for the Alzheimer's community," said Dr. David Hung, president and CEO of Pfizer's partner Medivation. Medivation shares plunged on the news in premarket trading, losing about two-thirds of their value.
The study was designed to show Dimebon's effects on thinking and overall function. The patients, who were about 74 years old on average, were given either 60 milligrams of Dimebon per day or a placebo for six months.
The New York drugmaker is also testing Dimebon on patients with moderate to severe Alzheimer's. The drug is also being studied in combination with Aricept or Namenda, which are common Alzheimer's drugs, as a treatment for Huntington's disease. Huntington's is a genetic disorder that causes uncontrollable muscle twitches and jerks, followed by a deterioration in mental abilities. It is progressive and fatal.
Pfizer said it is evaluating data from the CONNECTION study with Medivation, and will determine the next steps for Dimebon. The companies entered a partnership in September 2008, and if Dimebon is approved, Medivation could get hundreds of millions in milestone payments, as well as royalties on sales of the drug.
Medivation shares tumbled $27.85, or 69 percent, to $12.40 ahead of Wednesday's market open. The stock finished at $40.25 on Tuesday.
Pfizer shares fell 19 cents to $17.41.
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