Eli Lilly’s donanemab treatment slowed disease progression

The Alzheimer’s treatment donanemab, which is made by Eli Lillywhich significantly slowed the progression of the mental illness, according to clinical trial data published Wednesday by the company.

Patients who received the monthly antibody infusion in an 18-month study showed a 35% slower decline in memory, thinking and the ability to perform daily tasks compared to those who did not receive the treatment, Eli Lilly data showed.

Patients who took donanemab were 39% more likely to progress to the next stage of the disease during the study, according to the trial results.

But the benefits of the treatment must be weighed against the risk of brain swelling and bleeding which can be severe and even fatal in rare cases. Three participants in the trial died from these side effects.

Lilly plans to apply for Food and Drug Administration approval of donanemab as soon as this quarter, according to the company. The trial examined individuals in the early stages of Alzheimer’s who had a confirmed presence of brain plaque associated with the disease.

Dr. Daniel Skovronsky, Lilly’s chief scientific and medical officer, said that donanemab showed the highest level of effectiveness in any Alzheimer’s treatment in a clinical trial. The company is working to get donanemab approved and on the market as soon as possible, he said.

And Skovronsky believes the FDA feels the same sense of urgency.

“Every day that goes by, some patients go through this early stage of Alzheimer’s disease and become more advanced and don’t benefit from treatment,” he said in an interview with CNBC. That’s a sense of urgency.”

Lilly previously applied for accelerated approval for donanemab.

The FDA rejected that request in January and asked the company to get more data on patients who received the antibody for at least 12 months. Lilly said the data was not available at the time because many patients were able to stop dosing at six months because the treatment cleared their schedule quickly.

Nearly half of the patients — 47% — who received donanemab showed no disease progression a year after treatment began, compared with 29% who did not receive the antibody, according to the data released Wednesday.

More than half of the patients completed the treatment in the first year and 72% completed it in 18 months due to brain plaque clearance.

In a separate measure, patients who received donanemab showed 40% less decline in their ability to perform daily activities at 18 months. This means they were able to manage their finances better, drive, pursue hobbies and hold conversations better than those who did not receive the treatment.

“These are the strongest phase 3 data to date for the treatment of Alzheimer’s. This confirms the turning point we are at for the field of Alzheimer’s,” said Maria Carrillo, chief scientific officer of the Alzheimer’s Association, in a statement.

Donanemab targets a brain plaque associated with Alzheimer’s disease. The treatment significantly reduced the plaque as early as six months after treatment, according to Lilly. Many patients saw such reductions that they tested negative for the presence of plaque on their PET scans, according to the company.

Donanemab cleared the record at six months in 34% of patients who had intermediate levels of a protein called tau that can be toxic and kill neurons. At 12 months, donanemab cleared the plaque in 71% of patients with the same tau levels.

“It should be clear that drugs that remove plaque, especially if you can completely remove plaque and do it quickly, can provide very important clinical benefits to the patient,” Skovronsky said in an interview.

“The earlier in the course of the disease you do this, the more you can slow the disease,” he said.

Dr. Eric Reiman, executive director of the Banner Alzheimer’s Institute, said the results don’t necessarily mean the plaque is gone completely, but Donanemab cleared the plaque to the point that the treatment removed evidence of can be measured. Two physicians at the Banner Alzheimer’s Institute who participated in the donanemab trial were principal investigators.

Donanemab can cause brain swelling and bleeding in patients that can be serious and even fatal in some cases. Three trial participants died from these side effects, according to Lilly.

These types of side effects have been seen in other Alzheimer’s antibody treatments such as Eisai’s and Biogen’s Leqembi, which received fast-track FDA approval in January.

Reiman said he is encouraged by the potential clinical benefit for patients but it is important to be clear about the risks.

“We also need to be clear that there are side effects, including an unusual but potentially serious risk,” Reiman said. “And we need to continue to do our best to understand what the risk is to individual patients, to inform patients and family caregivers and what we can do to reduce that risk,” he said.

About 24% of patients who received donanemab showed brain swelling on MRI, but only 6% showed actual symptoms. About 31% of patients had small brain bleeds called microhemorrhages, compared to 13.6% among patients who did not receive the treatment.

Lilly said most cases of brain swelling and bleeding were mild to moderate and patients were stabilized with proper care, but warned that serious life-threatening events could occur. About 1.6% of the swelling and bleeding cases were severe, according to Lilly.

Skovronsky said that all patients need to have a discussion with their doctor who will weigh the potential benefits of donanemab against the potential risks.

“On a population basis, our view is that its benefits outweigh its risks,” Skovronsky said.

“FDA is that steward for the US,” he said of the risk-benefit analysis that will determine whether donanemab gets approval.