WASHINGTON — The Food and Drug Administration on Thursday approved the first drug for the treatment of Alzheimer's disease, a debilitating brain ailment that robs millions of elderly people of their memory, independence and dignity.
Tacrine hydrochloride, or THA, which will be marketed under the brand name Cognex, has been shown in two trials to provide small but meaningful benefits for some patients suffering from mild-to-moderate Alzheimer's.
"Tacrine is the first drug shown to have some effect on the disease's devastating symptoms," FDA Commissioner David A. Kessler said in a statement. "It is not a cure for Alzheimer's disease, but it provides some relief for patients and their families."
Its manufacturer, Warner-Lambert Co. of Morris Plains, N.J., said the drug could be available within weeks. It is expected to cost about $1,500 a year.
Alzheimer's disease is believed to afflict as many as 4 million Americans, most of them elderly. It is rare in people younger than 50, but it strikes about 10% of those older than 65 and nearly half of those 85 and older.
It is characterized by memory loss, disorientation, depression and deterioration of bodily functions.
Its cause is unknown, but symptoms are produced by the death of brain cells that secrete acetylcholine, a chemical known as a neurotransmitter, which is essential to many thought processes.
Tacrine blocks the function of enzymes that normally break down excess acetylcholine, thereby making more of the neurotransmitter available to brain cells.
Alzheimer's disease is ultimately fatal, resulting in an estimated 100,000 deaths annually in the United States. It is the fourth leading cause of death among adults after heart disease, cancer and stroke.
Many medical experts, however, say they believe that the disease is underreported because those with Alzheimer's often die from pneumonia or cardiac arrest.
The cost of care has been estimated at about $100 billion annually in this country, according to the Alzheimer's Assn.
In addition to its effect on patients, Alzheimer's disease is also a crushing burden for their families and other loved ones because it commonly renders the stricken individuals confused, forgetful, bad-tempered and virtually unable to care for themselves.
The FDA's approval of THA was based on studies of patients with mild-to-moderate Alzheimer's. The studies showed the drug superior to a placebo in a test that evaluated memory and reasoning ability. The research also included an overall assessment of function by a trained clinician.
"We're very, very excited; yesterday we had nothing, and today we have something," said Stuart Roth, chairman of the Alzheimer's Assn. "It is a ray of hope. In some cases, this drug will help patients perform daily duties they couldn't do before--and it will also ease some of the suffering of the care-givers."
An FDA advisory panel recommended last March that THA be licensed based on new studies submitted by the manufacturer.
Warner-Lambert conducted the new research after a federal advisory committee concluded in July, 1991, that results of low-dose studies did not support approval of the drug and recommended new studies using higher doses over a longer period of time.
Paul Solomon, a neuropsychologist who conducted the high-dose studies for the company, said the drug "did not help everyone" but that "we have seen a meaningful difference for a significant number of patients and their families."
He said there is no way to predict in advance who would be helped by the drug.
Dr. William K. Summers, a psychiatrist-internist who discovered the drug while working at UCLA and conducted the earliest studies, called THA "the first great therapeutic advance in the treatment of a thus far untreatable disease."
Summers, whose initial 1986 study was heavily criticized by the FDA and other scientists for being overly optimistic and poorly designed, said he finds vindication in news of the drug's approval. "This is terrific," he said.
Summers, who has been on sabbatical from his private practice in Arcadia to work for approval of the drug, predicted that as many as 75% of Alzheimer's patients could benefit.
But Solomon said his clinical work showed the percentage who showed improvement after using the drug was not as high as 75%.
"We have to have more experience with the drug," he said.
THA can cause mild liver toxicity, which is reversible if use of the drug is halted promptly. For that reason, the FDA recommended that patients take the drug in gradually larger doses and that they undergo frequent blood tests to detect sensitivity to the treatment.
Other side effects include nausea, vomiting, diarrhea and rash, the FDA said.
THA has been available since February, 1992, under a special program that gives patients access to experimental drugs under evaluation. More than 7,400 patients have already received the drug under this program, the agency said.
Roth suggested that individuals seeking information about the drug or about the disease call the Alzheimer's Assn.'s 24-hour, toll-free telephone number, 1-800-272-3900.