FDA Approves Second Alzheimer's Drug That May Slow Disease Slightly: NPR

WASHINGTON — U.S. authorities have approved a new Alzheimer's drug that may slow the disease somewhat, giving patients in the early stages of the incurable, memory-destroying disease a new option.

The Food and Drug Administration on Tuesday approved Eli Lilly's Kisunla for mild to early cases of Alzheimer's dementia. It is only the second drug to be convincingly shown to slow cognitive decline in patients, following the approval last year of a similar drug from Japanese pharmaceutical company Eisai.

The delay seen with both drugs is a matter of months — about seven months, in the case of Lilly's drug. Patients and their families will have to weigh that benefit against the downsides, which include regular IV infusions and potentially dangerous side effects such as brain swelling.

Doctors who treat Alzheimer's say the approval is an important step after decades of failed experimental treatments.

“I’m glad I have options to help my patients,” said Dr. Suzanne Schindler, a neurologist at Washington University in St. Louis. “It’s hard as a dementia specialist — I diagnose my patients with Alzheimer’s and then I watch them get worse every year and progress until they die.”

Both Kisunla and the Japanese drug Leqembi are lab-made antibodies, administered intravenously, that target one contributor to Alzheimer’s: the buildup of sticky amyloid plaque in the brain. Questions remain about which patients should receive the drugs and how long they might benefit.

Approval of the new drug was expected after an outside panel of FDA advisers unanimously voted in favor of its benefits during a public meeting last month. That approval came despite several questions from FDA reviewers about how Lilly studied the drug, including allowing patients to stop treatment after their plaque reached very low levels.

The cost varies by patient, depending on how long they take the drug, Lilly said. The company also said a year of therapy would cost $32,000 — higher than the $26,500 price of a year of Leqembi.

The FDA's prescribing information states that doctors may consider stopping the drug after brain scans show patients have minimal plaque.

More than 6 million Americans have Alzheimer's. Only those with early or mild disease will qualify for the new drug, and an even smaller subset will likely undergo the multi-step process required to get a prescription.

The FDA approved Kisunla, known chemically as donanemab, based on the results of an 18-month study in which patients who received the treatment declined about 22 percent slower in terms of memory and cognitive abilities than patients who received a sham infusion.

The main safety concern was brain swelling and bleeding, a problem common to all plaque-targeting drugs. The rates reported in Lilly’s study — including 20% ​​of patients with microbleeds — were slightly higher than those reported with rival Leqembi. However, the two drugs were tested in slightly different types of patients, making it difficult to compare the drugs’ safety, experts say.

Kisunla is administered once a month through an IV, while Leqembi needs to be administered twice a month. This can make it easier for caregivers who bring their loved ones to a hospital or clinic for treatment.

“It is certainly more attractive to have an infusion once a month than every two weeks,” Schindler said.

Lilly's drug has another potential advantage: Patients can stop taking it if they respond well.

In the company's study, patients were taken off Kisunla once their brain plaque reached nearly undetectable levels. Nearly half of the patients reached that point within a year. Stopping the drug could reduce the costs and safety risks of long-term use. It's not yet clear how soon patients would need to resume infusions.

Logistical hurdles, poor insurance coverage and financial concerns have all slowed the rollout of rival Leqembi, which Eisai is marketing with U.S. partner Biogen. Many smaller hospitals and health systems aren’t yet ready to prescribe the new plaque-targeting Alzheimer’s drugs.

First, doctors must confirm that dementia patients have the brain plaque targeted by the new drugs. Then they must find a drug infusion center where patients can receive therapy. Meanwhile, nurses and other staff must be trained to perform repeated scans to check for brain swelling or bleeding.

“These are all things that a physician has to have in place,” said Dr. Mark Mintun, who leads Lilly's neuroscience division. “Until they're in place, a patient who comes into their office is not going to be offered this therapy.”