Imaging advocates are urging the federal government to fix a coverage gap for PET scans following the FDA’s full approval of Alzheimer’s drug Leqembi.

The U.S. Food and Drug Administration first announced its decision on Thursday, July 6, converting from the “accelerated” approval granted earlier this year to the traditional endorsement. Officials made the determination following a large clinical trial confirming the monoclonal antibody’s benefits.

Beta-amyloid imaging via a positron emission tomography scan is crucial to pinpointing patients who are candidates for the drug. However, Medicare has imposed a lifetime limit of just one such amyloid-detecting exam per patient, who also need to be enrolled in a clinical trial. 

“While traditional approval of Leqembi is a milestone for Alzheimer’s patients, we remain concerned that access may be limited because beta-amyloid scans remain under Medicare’s coverage with evidence development policy, which creates access barriers to this cutting-edge technology,” Patrick Hope, executive director of the Medical Imaging & Technology Alliance, said in a July 7 statement. “In addition to removing the one-time limit on PET scans, it’s essential that CMS remove beta-amyloid PET from the CED policy to ensure that Alzheimer’s patients receive an accurate diagnosis in order to benefit from Leqembi.”

The drug works by targeting and eliminating the protein that builds up in the brains of individuals with Alzheimer’s. Its full FDA approval comes after trial results showing that Leqembi slowed the rate of cognitive and functional decline by 27% when compared to a placebo. The Society of Nuclear Medicine and Molecular Imaging similarly highlighted the approval while noting that the FDA has failed to provide guidance about the specific amyloid test providers should use. SNMMI said it will continue to engage with the Centers for Medicare & Medicaid Services, hoping to secure coverage for ongoing PET exams as part of treatment, along with the initial scan to confirm the presence of such plaques.

“Amyloid PET scans are an essential tool that will allow physicians to identify appropriate candidates for Leqembi,” SNMMI President Helen Nadel, MD, said in a statement issued Monday, July 10. “PET scans should also be performed on patients after they begin taking lecanemab to ensure that the amount of amyloid plaque has decreased.”

CMS intends to soon propose a new national coverage determination that would loosen restrictions around PET payment, Inside Health Policy reported Monday.