Biogen and Eisai have spent much of Leqembi’s launch convincing physicians and patients that it’s safe to treat Alzheimer’s disease. With patients now hitting the 18-month mark of treatment, the conversation is finally shifting to efficacy.
With the launch of Alzheimer’s disease medicine Leqembi charting “slow and steady” growth, Biogen CEO Chris Viehbacher said that promotion can now turn to the actual benefits of the product.
“There was an awful lot of effort at the start just to explain care pathways and the side effects and the reimbursement,” the CEO explained during Biogen’s fourth quarter earnings call Wednesday morning. “And I think now we can actually focus a lot more on the value proposition and treating patients. I think there’s a huge opportunity in expanding the prescriber base.”
Leqembi brought in $87 million for the quarter, including U.S. sales of $50 million. The result was above analysts’ consensus, which was around $76 million, and represents about 30% quarter-on-quarter growth. Viehbacher expects the upward trend to continue, with IV maintenance formulations.
“It is clear that in the short term, we have a lot of capacity constraints, but I think we’ve made a lot of progress in relieving some of those,” Viehbacher said.
Viehbacher noted that outside of the U.S., sales growth is strong, thanks to partner Eisai’s marketing prowess in Asia. Typically, drugs launch and grow quickly in the U.S. first, the CEO added.
Leqembi has now been on the market long enough that the first patients are hitting the 18-month treatment mark, Viehbacher said. These patients have seen their classic Alzheimer’s amyloid-beta plaques cleared, but the data show they must continue treatments to prevent the plaques from coming back. Viehbacher said this differentiates Biogen from competitor Eli Lilly, which allows patients to stop taking its Kisunla once their plaques are clear.
“It’s not just about plaque clearance, it’s about maintaining that clearance,” Viehbacher said.
Viehbacher said the data show Leqembi could stabilize about 76% of patients, which is a stat that needs to become central to demonstrating the value of the medicine.
“People forget that this is a fatal disease,” the CEO said of Alzheimer’s.
To drive growth, Biogen has applied for subcutaneous administration for maintenance treatment with the FDA, which would bring the treatment into patients’ homes. With a target action date of Aug. 31, 2025, Viehbacher expects that to begin making an impact in the latter half of the year. An application for subcutaneous initiation treatment is planned for 2026.
Biogen would also like to see FDA approvals for more Alzheimer’s diagnostics that can help patients avoid a PET scan or lumbar puncture.
“Something like 50% of patients who actually manage to get into a neurologist are actually not eligible for treatment because they’re too far advanced in their disease,” Viehbacher said on the earnings call. “So if we could actually triage some of these patients, particularly at the primary care level, then we can actually get a higher quotient of patients who visit a neurologist actually being eligible for treatment.”
Biogen is testing Leqembi in a Phase III trial for patients with presymptomatic Alzheimer’s. A key readout is expected in 2028. The company is also testing BIIB080 in a Phase II trial for Alzheimer’s.
“We obviously continue to believe that Alzheimer’s can be a significant market, and that’s why we’re investing not only in tau, but in other modalities,” Viehbacher said. “The unmet need is incredible.”
A Worthy Hypothesis
Elsewhere in Alzheimer’s, Novo Nordisk is testing its mega-blockbuster GLP-1 against the disease in the Phase III Evoke and Evoke+ trials. Results from Evoke are expected in the second half of this year, according to Novo’s investor presentation from fourth quarter earnings.
Asked whether the standard of care in Alzheimer’s could shift if the results are positive, Biogen’s Head of Development Priya Singhal said on the call that her team is watching the study closely. “It’s a very interesting hypothesis . . . and it’s worthy of exploring.”
But Singhal pointed to the long history of failure in drug development for the brutal neurodegenerative disease—something Biogen knows plenty about with its former medicine Aduhelm, who received an FDA greenlight in June 2021 only to be pulled from the market in January 2024 after much controversy. (See timeline.)
“What I think is really important to continue to remember is that when you’re tackling something like Alzheimer’s disease, you need to tackle the central pathology,” Singhal said. “We continue to believe that an anti-amyloid agent like Leqembi that really addresses plaque but continues to address soluble, toxic species after plaque clearance, will have an important role to play.”
