Tuesday, Pfizer Inc. (PFE) and Medivation Inc. (MDVN) announced the initiation of Contact and Constellation, two Phase 3 trials of the investigational drug Dimebon in patients with moderate-to-severe Alzheimer's disease.
Alzheimer's disease is a neurodegenerative disorder that affects more than 5.3 million families in the United States each year. The disease carries an annual societal price tag of $148 billion, according to the Alzheimer's Association. It destroys brain cells, which causes memory loss and problems with thinking, and the behavior of patients with the disease can deteriorate to the point that it affects work, lifelong hobbies and social function. Alzheimer's gets progressively worse, and it is fatal.
The company noted that the Contact study will assess as primary endpoints the potential benefits of adding Dimebon to ongoing treatment with donepezil HCI tablets on neuropsychiatric symptoms and activities of daily living. The Constellation study will evaluate as primary endpoints the effects of adding Dimebon to memantine HCI, another standard of care, on cognition, memory and activities of daily living. Pfizer said that in preclinical studies, Dimebon has been shown to protect brain cells from damage and enhance brain cell survival, potentially by stabilizing and improving mitochondrial function.
In preclinical studies, Dimebon has been shown to protect brain cells from damage and enhance brain cell survival, potentially by stabilizing and improving mitochondrial function. The Dimebon mechanism is distinct from currently available AD medications.
The company revealed that these studies are part of a comprehensive late stage clinical development program, currently consisting of seven trials, to assess the safety and efficacy of Dimebon across all stages of Alzheimer's disease, as monotherapy and in combination with currently available Alzheimer's treatments, and in Huntington disease.
Dimebolin hydrochloride, branded as Dimebon, is an antihistamine drug which has been used clinically in Russia since 1983. 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 are working in partnership to advance the Phase 3 development program with the goal of submitting a new drug application to the FDA and bringing Dimebon to market in the United States.
PFE is currently being traded at $16.80 down $0.15 or 0.88% on a volume of 14.039 million shares on the NYSE.
MDVN is traded at $26.38 up $0.23 or 0.88% on the Nasdaq.
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June 12, 2026 17:14 ET Major central bank action was the focus this week in economic news. The European Central Bank became the first major central bank to move in response to the rising inflationary pressures in the backdrop of the conflict in the Middle East. In North America, the U.S. inflation and trade data as well as Canada’s central bank decision gained attention. The Chinese trade data was the main news in Asia.