After being widely criticized for approving the use of a new drug to treat all Alzheimer's patients, despite only limited evidence that it works, the Food and Drug Administration has stepped back from that decision. The agency announced its new instructions Thursday that say Aduhelm is intended only for people in the early stages of the disease, the Washington Post reports—patients with mild cognitive impairment or early dementia. The FDA and Biogen, which makes the drug, said that's who took part in Aduhelm's clinical trials. The change in the instructions that appear on the label could mean that 1.5 million people are candidates for the treatment instead of 6 million, per the New York Times. An FDA spokesman said the agency acted in response to "confusion regarding the intended population for treatment."
One expert involved on one of the clinical trials said the pool of eligible candidates for treatment should be narrowed even more. People with diabetes and high blood pressure weren't included in the trials, Dr. Lon Schneider said. Nor were people who take blood thinners. So "we don't know any extent of increased risk" for such patients, he said, adding that the Aduhelm label should have a warning to those people. The treatment received "accelerated approval" from the FDA, which told Biogen to produce a study confirming that the treatment helps patients in nine years. The company said the label update was its idea, after conferring with physicians, the agency, and patient advocates, per the Wall Street Journal. Biogen stock is up 29% since Aduhelm was approved a month ago. (The cost of the drug could threaten the future of Medicare.)