Eisai, Biogen likely to miss early launch goal for Alzheimer's drug Leqembi

Even with Leqembi now sporting a full FDA approval and benefiting from the simpler Medicare coverage that distinction brings, Eisai and Biogen’s latest Alzheimer’s disease med appears to be moving slower than expected.

While Japan’s Eisai had set the goal to reach 10,000 patients with Leqembi by the end of its 2024 fiscal year, which wraps up in March, only 2,000 patients in the U.S. were receiving the amyloid-busting antibody as of Jan. 26, Eisai explained in a third-quarter earnings presentation.

That low rate of adoption isn’t for lack of demand, considering there are some 8,000 U.S. patients currently waiting to get on treatment, Keisuke Naito, Eisai’s global Alzheimer’s disease officer, said on a call with analysts this week.

“We understand that there is great demand from patients as well,” Naito said. “We believe that as the diagnosis and the treatment pathways are established and implemented … then we will be able to administer Leqembi to these patients.”

In the coming few months, Eisai expects the number of patients who can receive Leqembi to “increase rapidly,” Naito said. In particular, many patients are currently waiting for treatment in states such as New York, California and Florida.

Even still, Eisai’s goal to reach 10,000 patients by the end of its 2023 fiscal year will be “rather challenging,” Naito admitted.

As it stands, Leqembi is now bringing in about $1.5 million per week, according to Naito. For all of the third quarter, the drug generated 1.1 billion Japanese yen in U.S. sales (around $7.4 million).

As Eisai progresses with the launch, the company hopes to expand its Alzheimer’s business by introducing maintenance dosing and a subcutaneous formulation of Leqembi, which would provide “more convenience to patients,” he explained.

Meanwhile, the company has a major opportunity ahead of it thanks to the recent approval of Leqembi in China, where Eisai estimates there will be 17 million patients with mild cognitive impairment or mild dementia due to Alzheimer’s in 2024.

Eisai will be in charge of distributing the product in China, where it will focus on Alzheimer’s awareness and collaborate with specialists to improve the diagnostic environment, including that for blood-based biomarkers, the company said in a press release last month.

For 2024, Eisai is aiming to reach 1,500 patients in China, though it figures that growth will accelerate significantly in 2025 as diagnosis methods evolve, a company spokesperson told Reuters.