Eisai's Alzheimer's drug Leqembi gaining ground with US neurologists, but most waiting on full approval: Spherix

U.S. neurologists are “cautiously optimistic” about using Eisai’s Leqembi in Alzheimer’s disease as concerns about safety and the need for the FDA’s full green light for the drug remain high barriers to uptake.

That’s according to a new survey and report out by drug launch analyst Spherix Global Insights, which in March asked 73 neurologists working in the U.S. about their use and receptivity of Leqembi, which was partially approved by the FDA at the start of the year.

Now launched, the drug finds itself at a strange junction. It still does not have a full FDA approval; that isn’t set to come until early July. While there is another new drug on the market for Alzheimer’s—namely Aduhelm, which Eisai helped create with Biogen—that drug is commercially dead in the water.

The Centers for Medicare & Medicaid Services (CMS) refused to cover payments of Aduhelm, which was also hit by the controversial way the FDA approved the drug in 2021. The drug passed the regulatory hurdle despite some serious safety and efficacy questions, not least from the FDA’s own drug review experts who denied its approval at the drug’s advisory committee and were overruled by the FDA proper several months later.

That leaves Leqembi, which works in a similar way to Aduhelm, in a “fraught market,” Spherix notes, despite not having any real competition.

CMS said in February that it wouldn't cover Leqembi, but three weeks later, the U.S. Veterans Health Administration decided to cover the treatment. Eisai has placed a $26,500 annual list price on the amyloid beta plaque reducing agent, nearly half the original price of Aduhelm at launch.

Spherix said that there was a “healthy proportion” of survey respondents already prescribing the therapy one month after commercial availability, though it did not reveal the exact numbers in its release.

It also found that most who were surveyed “intend to wait” until the drug gets full FDA approval, “meaning broader uptake will be delayed." But there is good news should that happen as nearly all respondents “expect to prescribe the brand, with most starting in the first year following traditional approval,” according to the report.

However, there are safety concerns from the drug that could pose a barrier. The worry centers on amyloid-related imaging abnormalities (ARIA), a serious safety signal that could mean an edema common in many anti-amyloid drugs on the market and in trials, which requires close monitoring of patients.

Most neurologists in the Spherix survey expressed “at least moderate concern regarding ARIA in Leqembi-treated patients, with only a minority believing that the benefits of the [drug] outweigh the risks of ARIA,” the report noted.

As one interviewed neurologist summarized ARIA-related concerns, “Every time a patient has a complaint, you’re going to be saying, ‘Do I need to scan them? Do I need the MRI? Is it ARIA?’”

Spherix still sees the drug as a potential big seller. Another analyst group, Evaluate Vantage, also sees Leqembi gaining commercial steam throughout the decade. Its experts recently pegged worldwide sales at $3 billion in 2028, while GlobalData places the figure at roughly $4.6 billion.