NEW YORK – Biogen is "doubling down" on its drug development efforts in Alzheimer's disease, company President and CEO Christopher Viehbacher said Tuesday at the JP Morgan Healthcare Conference in San Francisco.
Biogen in recent years has faced setbacks in this franchise as it struggled to market Aduhelm (aducanumab) amid a controversial approval and mixed efficacy data. Although Aduhelm held the distinction of being the first anti-amyloid Alzheimer's drug to reach the US market, Biogen ultimately decided to discontinue development of the drug last year.
That experience didn't dissuade the company from advancing another Alzheimer's candidate. Leqembi (lecanemab), codeveloped by Biogen and Eisai, in 2023 became the second drug in the anti-amyloid class to reach the market and the first to earn traditional approval from the US Food and Drug Administration. Biogen continues to develop Leqembi and has a drug targeting a different Alzheimer's protein biomarker in its pipeline.
"There is still significant unmet need in Alzheimer's, and therefore, there is also significant commercial opportunity," Viehbacher said. "We're doubling down on Alzheimer's."
Leqembi's uptake will be slower than other drugs, he noted, in part because of its complexity, as it requires cognitive assessments, beta-amyloid testing, and imaging studies. Leqembi, which is indicated for early Alzheimer's patients with evidence of beta-amyloid pathology, is administered intravenously every other week, though Eisai and Biogen have proposed that patients eventually would be able to switch to less burdensome maintenance treatment.
Still, Viehbacher cited multiple opportunities to accelerate Leqembi's growth. The firm is pursuing FDA approvals in additional indications and gathering evidence on the drug's use in presymptomatic Alzheimer's.
Eisai, which leads development and regulatory submissions for Leqembi, has submitted applications with the FDA seeking approval for intravenous and subcutaneous forms of the drug that can be dosed as maintenance treatments after patients complete an initial regimen of infusions. The FDA is expected to decide on intravenous maintenance dosing later this month and subcutaneous maintenance dosing in August.
Cambridge, Massachusetts-based Biogen and Tokyo-based Eisai are also investigating a subcutaneous version of Leqembi that could be used in the initiation phase of treatment and are currently working to establish an optimal dose. They expect to receive a regulatory decision on this indication early next year.
A subcutaneous formulation could ease some of the burden on physicians and patients, since patients would be able to receive the drug at home and not have to travel to an infusion center, Viehbacher said. Even intravenous maintenance dosing would make the process more convenient by reducing the dosing to monthly instead of biweekly.
Viehbacher during his presentation highlighted the subcutaneous formulation as a "clear point of differentiation" between Leqembi and its other competitor on the market, Eli Lilly's Kisunla (donanemab), which was approved by the FDA last year. Kisunla is an intravenous infusion that's administered monthly until patients reach an established threshold of beta-amyloid clearance, at which point they can stop treatment.
Despite the potential of a growing class of anti-amyloid drugs, Viehbacher said he expects Leqembi and Kisunla will likely continue to lead the market through the end of the decade. "We're not as big and powerful as Lilly, but we'll be able to stand our ground on the competition," he said. "We have enough points of differentiation that we can be successful here."
The availability and adoption of blood-based tests to measure beta-amyloid pathology could also spur uptake by making such assessments more convenient and quicker to conduct. "If you can dispense with the lumbar puncture, and you can reduce the need for infusion beds, the burden on the physician will get lighter," Viehbacher said.
Separately, Eisai and Biogen are studying Leqembi in the Phase III AHEAD 3-45 study, which completed enrollment late last year. In this study, the companies are assessing whether Leqembi can be administered earlier to patients with elevated beta-amyloid, but without Alzheimer's symptoms, to delay or prevent cognitive decline.
Viehbacher suggested, down the line, it could become common to see seniors get tested for Alzheimer's biomarkers as part of routine blood work to identify their risk before symptom onset.
The other Alzheimer's drug in Biogen's pipeline, BIIB080, is an antisense oligonucleotide designed to reduce production of tau, another Alzheimer's-linked biomarker. The company is evaluating BIIB080, which it licensed from Ionis Pharmaceuticals, within the Phase II CELIA trial. In that study, patients receive either a placebo or the drug, which is administered intrathecally quarterly or semi-annually — less frequently than Leqembi and Kisunla. Biogen anticipates a data readout from the Phase II trial in the first half of next year.
Based on early clinical and biomarker trends from a Phase Ib trial, Viehbacher said he expects BIIB080 could potentially have greater efficacy than Leqembi by targeting tau. "Biogen's view is that Alzheimer's is really an amyloid-driven tauopathy," Viehbacher said.