A drug used to treat advanced prostate cancer and endometriosis stabilized memory in women with Alzheimer's disease for more than a year, according to a study conducted at the University of Wisconsin School of Medicine and Public Health.
That makes the drug, known as Lupron Depot, the most effective for slowing the progression of Alzheimer's for an extended period. However, because the patent on the drug has nearly expired, it promises little payoff as an Alzheimer's drug, so further research on its effects appears unlikely.
"I would hope someone would see its potential, repeat our study and see if they get the same results," said Dr. Richard Bowen, a lead author of the study who has been researching Lupron Depot's effect on Alzheimer's for two decades. "However, there's no exclusivity, so there's not much of a way for a company to fund research because there's little potential profit in it."
The clinical study, published online Jan. 22 in the Journal of Alzheimer's Disease, involved 109 women with mild to moderate Alzheimer's disease. About half received Lupron Depot, plus Aricept or some other commonly prescribed acetylcholinesterase inhibitor that temporarily slows memory decline in Alzheimer's patients. The other half received an acetylcholinesterase inhibitor plus a low dose of Lupron Depot alone, or a placebo.
Those who took a high dose of Lupron Depot with their acetylcholinesterase inhibitor showed almost no decline in their scores on a common memory test over one year, while those who took only an acetylcholinesterase inhibitor showed an average decline of 3.3 points. Surprisingly, those who took Aricept or its equivalent plus a small dose of Lupron Depot did worse, recording an average loss of 4.21 points on the memory test over a year.
Interest in Lupron Depot as a treatment for Alzheimer's began in 1995 when Bowen, then a physician in Sarasota, learned of a patient with prostate cancer and Alzheimer's disease whose memory problems halted for eight years while he was on the drug. Investigation showed that men taking Lupron Depot had a 50 percent reduction in their risk of Alzheimer's, so Bowen tried to raise the millions of dollars required to conduct a clinical trial. He helped create a company devoted to developing Lupron Depot as a treatment for Alzheimer's and set out to raise $85 million for a clinical study. The company failed, and research stopped, so Bowen presented the data at an Alzheimer's meeting last year, hoping to arouse interest in Lupron Depot as a treatment for Alzheimer's.
Although not approved for Alzheimer's, some doctors have prescribed Lupron Depot "off-label" in hopes of slowing Alzheimer's in their patients. Dr. Robert Tober of Naples, for example, has prescribed Lupron Depot to several men with Alzheimer's who also had prostate cancer.
"I spoke to families at length and said this is not an approved therapy for dementia, but it's widely used for prostate cancer," he said. "With an absolutely clear conscience I was able to say to people that Lupron Depot is a possible life preserver that will delay the progression of Alzheimer's. The downside was they had to buy the drug themselves, which was very expensive."
Family members told him these patients were more alert, and some even seemed to return to the way they used to be. "The family of the last person I treated said they thought God had sent me to them to provide this drug," he said. "I visited him five years later and he called me by name. He showed no evidence of the intellectual slide I've seen in Alzheimer's, but I have no way of proving the drug was responsible."
Tober approached executives of drug companies to make a case for Lupron Depot as a treatment for Alzheimer's, "but every one of them said this drug is off patent. One executive told me, 'I have a board of directors to face. You need a billionaire willing to spend a tenth of his billion to finance a study.' "
Tom Valeo writes on health matters. Contact him at firstname.lastname@example.org.