Backers of PET amyloid imaging, who have been on the edge of their seats waiting for a coverage decision from Centers for Medicare and Medicaid Services since January, received some disappointing news on July 3.

In its proposed decision memo for amyloid PET imaging, CMS said there was insufficient evidence to conclude that Amyvid, the drug used in PET amyloid scanning, improves health outcomes for Medicare beneficiaries with Alzheimer's and related dementia.

However, CMS did agree to cover one Amyvid PET scan to exclude Alzheimer's disease, but only for patients enrolled in clinical trials under what is known as a coverage with evidence development program.

"CMS appears to be challenging the value of an adjunctive tool that can assist physicians in making a more informed diagnosis for patients with cognitive impairment. Restricting coverage could hinder a timely and accurate diagnosis, which is in conflict with the advice of Alzheimer's disease experts and with the administration's National Alzheimer's Project Act," said Dr. Daniel Skovronsky, president of Avid Radiopharmaceuticals, Inc., a subsidiary of Eli Lilly and Company, in a statement. "In addition, it may stifle future innovation aimed at improving diagnosis."

Eli Lilly & Co.'s Amyvid received U.S. Food and Drug Administration approval last spring. It's used in PET scans to help physicians measure beta-amyloid plaque load in the brain, which is associated with Alzheimer's disease.

According to the language of Amyvid's FDA approval, a positive scan is not diagnostic for Alzheimer's, but a negative scan could help physicians rule out Alzheimer's in favor of other types of dementia.

The Medicare Evidence Development & Coverage Advisory Committee, or MEDCAC, voted in late January that there wasn't enough evidence to determine whether Amyvid could help improve outcomes for patients with early signs of cognitive dysfunction. Skeptics on the panel said they wanted more studies that include enough patients with unexplained mild cognitive impairment, thought to benefit most from the scans, and they also wanted proof that the drug actually changed patient management. Although the MEDCAC panel doesn't have the authority to make coverage decisions, CMS relies on its advice when making them.

In a statement released July 8, the Society of Nuclear Medicine and Molecular Imaging said that appropriate use criteria they released jointly with the Alzheimer's Association earlier this year highlights indications for which immediate coverage is warranted and demonstrates that "more than adequate evidence exists for Medicare to cover without additional onerous steps." They also said they do not believe coverage with evidence development is appropriate for this test, which the FDA has already approved, noting its clinical utility.

SNMMI is also working on a comprehensive education program for physicians who will be referring patients and those who will be reading the scans.

CMS is accepting public comment on the decision memo for PET amyloid imaging. A final decision is expected in October.