Dr. David Reuben's phone started ringing nonstop Monday, after the Food and Drug Administration approved the first new drug for Alzheimer's disease in nearly two decades.
Reuben, director of the UCLA Alzheimer's and Dementia Care Program, said patients and, more often, patient's families, were clamoring for the drug.
They ask, "How can we get Mom on this drug?" or "How can I get this drug?" he said.
The approval of the drug, called aducanumab, has thrown doctors into a precarious position, forcing them to make difficult decisions about who should receive a pricey therapy with unclear benefits. Reuben also noted that despite approval, the therapy is not immediately available. Last year, an advisory panel to the FDA urged the agency to reject the drug, made by the Massachusetts-based biotech company Biogen, because clinical trials did not show it had a measured benefit.
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"To say that it works right now would be a lie," said Dr. Aroonsiri Sangarlangkarn, a geriatrician and an assistant professor of medicine at Temple University Hospital in Philadelphia. "I need better data for me to be able to say that there's a potential benefit that outweighs the risks," she said.
Aducanumab, sold under the name Aduhelm, is a monthly infusion meant to reduce clumps of proteins in the brain called amyloid, a marker of Alzheimer's disease. In theory, clearing the brain of amyloid plaques may slow the progression of the memory-robbing illness. While the drug was shown to reduce these plaques in trials, it did not show subsequent changes in how patients progressed.
"This is not, 'Bring Mom back to two years ago,'" said Dr. Babak Tousi, head of the clinical trials program at Cleveland Clinic's Lou Ruvo Center for Brain Health. However, "if it is used for the right patient, at the right time, you'd expect to see some slowdown of disease," said Tousi, who was also a principal investigator of clinical trials of aducanumab at the Cleveland Clinic.
But who is that right patient? To the surprise of some experts, the FDA did not specify on the drug's label that it should be limited to patients in the early stages of the disease. Trials only included patients in the earliest stages of dementia, called mild cognitive impairment. It's that group who might stand to benefit, but they are not easily diagnosed.
That's because mild cognitive impairment can be difficult to distinguish from signs of normal aging: Some memory slips are expected as people age, while others portend a true decline in brain function.
"It's going to be tricky identifying patients who are eligible for the medication," said Dr. Liron Sinvani, a geriatrician at the Feinstein Institutes for Medical Research at Northwell Health in New York.
Tousi agreed. "It's not easy," he said. "People can cover it up quite well."
Normal aging may include trouble remembering which night of the week a person dined on salmon, for example. A person with mild cognitive impairment, on the other hand, may have no idea what he or she ate last night for dinner.
By the time patients in the earliest stages of dementia are identified, it may be too late. Aducanumab has not been tested in patients with more severe dementia.
"By the time we get them, their memory impairment is more progressive," Sinvani said of her patients.
Indeed, Reuben estimated that just a fraction of his patients — 5 to 10 percent — may be helped by the drug.
What's more, any tangible results from aducanumab's clearing of amyloid may not be apparent for at least a year or more — at an estimated annual cost of $56,000. The best patients can hope for, experts say, is to lose as little memory function as possible.
"I think that the relevance of it will apply to few of my patients," Sinvani said. "But for a very specific population in which the patient and caregiver partners agree to participate and want to take the medication, I won't stop them."
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