- Biogen said it is not worried about competing with Eli Lilly as they both try to roll out drugs to treat the early stages of Alzheimer's disease.
- Biogen CEO Christopher Viehbacher said Eli Lilly's decision to stop dosing the drug after it clears a certain amount of toxic amyloid brain plaque in a patient may not be the best approach.
- Eli Lilly and Biogen may need to consider rolling out maintenance doses that will keep brain plaque levels low, the executive said during a Q1 2023 earnings call.
"I think it will be good if there are other players in the market, but I don't think we are too concerned about competing with donanemab," Christopher Viehbacher, the chief executive, said during the company's first quarter earnings call, referring to one of Eli Lilly's potential Alzheimer's treatments.
Clinical trial data on both Eli Lilly's donanemab and leqembi, a highly anticipated drug from Biogen and Japanese drugmaker Eisai, indicate they reduce a protein called amyloid. The protein builds up on the brain in Alzheimer's patients and disrupts cell function.
Researchers argue that the accumulation of amyloid plaque is a crucial first step toward the cognitive decline observed in Alzheimer's disease. More positive data on donanemab "further reinforces" that argument, according to Viehbacher.
But he said Eli Lilly's decision to stop dosing the drug after it clears a certain amount of amyloid plaque in a patient may not be the best approach to treating the disease.
"Most neurologists I talked to don't believe that fits anymore with the way we're thinking about the treatment of Alzheimer's," Viehbacher said.
Eli Lilly didn't immediately respond to a request for comment.
Patients in a phase two trial on donanemab stopped dosing as early as six months due to clearing amyloid plaque in their brains. Fewer than 100 patients received 12 months of the drug.
The Food and Drug Administration declined to grant accelerated approval for donanemab in part due to the lack of data on longer term use of the drug.
Viehbacher noted that amyloid plaque will accumulate in the brain again even after an Alzheimer's drug manages to clear it. He said that will likely require Eli Lilly and Biogen to roll out maintenance doses that will keep plaque levels low.
Biogen and Eisai expect the Food and Drug Administration to grant full approval of leqembi by the summer. The companies are already preparing to apply for approval of maintenance doses by the first quarter of 2024, Biogen said in its first quarter earnings report.
Eli Lilly has not announced similar maintenance dosing plans for donanemab. The company plans to unveil data from a phase three trial on donanemab during the second quarter this year.
The two drugmakers are racing to bring a new Alzheimer's treatment to the market after both of their previous drugs flopped.
Biogen is banking on the success of its drug leqembi after the disastrous approval and rollout of its old Alzheimer's drug aduhelm last year.
The company said it booked an $18 million loss from Alzheimer's disease treatments during the first quarter.
Eli Lilly is developing donanemab and another drug, remternetug, after the company's older treatment, solanezumab, failed to slow the progression of Alzheimer's in clinical trials.
An estimated 6.7 million Americans age 65 and older are living with Alzheimer's, according to the Alzheimer's Association. By 2050, that group is projected to rise to almost 13 million.
One in three seniors die with Alzheimer's or another form of dementia, which kills more people than breast cancer and prostate cancer combined, the association said.