New drug may alter Alzheimer's, Huntington's care

The Chief Executive of Medivation Inc said on Friday experimental drug Dimebon has the potential to transform care for both Alzheimer's and Huntington's disease and achieve blockbuster sales.

David Hung said Dimebon has shown impressive results in clinical studies in stabilizing the thinking and memory of patients with Alzheimer's disease for a year or longer and improving the memory of those with Huntington's, a hereditary disease that causes loss of brain cells and mental deterioration.

By contrast, Hung said most current Alzheimer's treatments only help patients about 12 weeks before the condition worsens and the only approved medicine for Huntington's actually worsens cognition.
"If we can get a drug out onto the market that is really effective and safe, that will probably increase the incentive of doctors to diagnose Alzheimer's early on and to treat it," Hung said in an interview.

That could greatly bolster the current $5 billion a year market for Alzheimer's drugs. The category is now dominated by Pfizer Inc's Aricept -- a drug deemed minimally effective in improving the symptoms of patients with the degenerative brain disease.

Medivation signed a partnership last year with Pfizer, the world's largest drugmaker, which entitles the tiny San Francisco-based biotechnology company to 40 percent of U.S. profits from Dimebon and an undisclosed royalty on overseas sales.

Hung said Dimebon met its primary goal in one pivotal study, as well as all four secondary goals, and raised no safety concerns.

That stands in contrast to a highly watched experimental drug for Alzheimer's being developed by Wyeth, called bapineuzumab, which failed to meet its primary goal in a mid-stage trial and caused brain swelling at higher doses.

"And for Huntington's disease, there were fewer adverse events with Dimebon than with placebo," Hung said.

Medivation licensed Dimebon from a privately held Russian company that had sold it as an antihistamine. But Hung said the drug seems to help Alzheimer's and Huntington's patients by preventing damage to mitochondria: tiny units of all cells that supply energy.

"A number of neuro-degenerative diseases appear to be caused by different things that harm mitochondria," he said, and cells, including neurons, become sick and die.

"If we can inhibit neuron injury or death, it's better to do it sooner than later" by attempting to diagnose Alzheimer's and Huntington's as early as possible and begin treatment.

Hung added that U.S. regulators are requiring Medivation to complete another successful pivotal trial before Dimebon can be approved for treatment of mild to moderate Alzheimer's. Several such trials are expected to be underway later this year.

Hung also expressed confidence in a second Medivation drug, called MDV3100, now being tested among patients with advanced prostate cancer who failed to benefit from standard treatment.

He said the drug has dramatically reduced the number of lingering cancer cells after surgery -- so-called circulating tumor cells -- a sign it may be able to prolong survival in planned late-stage studies.

Source : www.guardian.co.uk