A panel of advisers to US health regulators backed a drug to slow Alzheimer's disease on Monday setting the stage for its expected approval for patients at an early stage of the disease.
The advisers voted unanimously that the drug's benefits outweighed its risks, which include side effects like brain swelling and bleeding that will have to be monitored.
"I thought the evidence was very strong in the trial showing the effectiveness of the drug," said panel member Dean Follmann, a National Institutes of Health statistician.
The drug, donanemab, is from pharmaceutical company Eli Lilly and has been shown to slow cognitive decline due to Alzheimer's.
Lilly's approach to studying its once-a-month treatment prompted questions from the US Food and Drug Administration (FDA) reviewers.
Patients in the company's study were grouped based on their levels of a brain protein, called tau, that predicts the severity of cognitive problems. That led experts to question whether patients might need to be screened for tau before getting the drug.
But most panellists thought there was enough evidence of the drug's benefit to prescribe it broadly, without screening for the protein.
Stopping treatment
A review panel looked at the data due to unusual approaches in how the drug was tested, including taking patients off the drug when they reached low levels of amyloid, sticky brain plaque that contributes to Alzheimer's.
Lilly scientists suggested stopping treatment is a key advantage of the drug, which could reduce side effects and costs.
But FDA staff said Lilly provided little data supporting the optimal time to stop or how quickly patients might need to restart treatment.
Despite those questions, many panellists thought the possibility of stopping doses held promise.
“It’s a huge cost savings for the society, we’re talking about expensive treatment, expensive surveillance,” said Dr Tanya Simuni of Northwestern University.
She and other experts said patients would need to be tracked and tested to see how they fare and whether they need to resume treatment.
Side effects
The main safety issue with donanemab was brain swelling and bleeding, a problem common to all amyloid-targeting drugs. Most cases identified in Lilly's trial were mild.
Three deaths in the donanemab study were linked to the drug, according to the FDA, all involving brain swelling or bleeding. One of the deaths was caused by a stroke, a life-threatening complication that occurs more frequently among Alzheimer's patients.
FDA's panel agreed that those risks could be addressed by warning labels and education for doctors as well as medical scans to identify patients at greater risk of stroke.
