Top researchers who advised the U.S. Food and Drug Administration on Biogen Inc.’s Alzheimer’s drug blasted the agency for approving it, calling the decision a "regulatory failure” that is "at odds with the evidence.”

The New England Journal of Medicine opinion piece, signed by seven members of an advisory panel that opposed clearing Biogen’s Aduhelm, is another sign of persistent furor over the agency’s decision. Two committees of the House of Representatives investigating the approval have asked the Cambridge, Massachusetts-based biotech to turn over documents about the drug’s development and approval.

Doctors and patients are desperate for new treatments for Alzheimer’s disease, which afflicts more than 5 million Americans. While many researchers have backed the FDA’s move, the drug hasn’t been shown to slow cognitive decline, as two big trials sponsored by Biogen yielded contradictory results. Three of the panel members resigned in protest shortly after the FDA approved the drug.