The Food and Drug Administration granted traditional approval to Leqembi, the Alzheimer’s treatment jointly developed by Biogen and Eisai, Thursday afternoon.

In early June, external advisors to the FDA unanimously recommended Leqembi for full approval. The widely expected approval comes six months to the day after the FDA gave the drug a greenlight through its accelerated pathway program. 

“Today’s action is the first verification that a drug targeting the underlying disease process of Alzheimer’s disease has shown clinical benefit in this devastating disease,” said Teresa Buracchio, acting director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research, in a statement. “This confirmatory study verified that it is a safe and effective treatment for patients with Alzheimer’s disease.”

Leqembi’s initial launch has rolled out in strong fashion, complete with first recorded sales, prescription written and patient infusion over the past few months. The drug is on track to be a blockbuster, with one analysis projecting nearly $13 billion in global sales by 2028. This would be 17-times the sales total of Aricept, the second-longest approved Alzheimer’s drug.

Ivan Cheung, Eisai SVP, global Alzheimer’s disease officer, and president of the Americas region, said earlier this spring that the launch has been “smooth and very much on-track.”

In a statement following the announcement, Eisai CEO Haruo Naito applauded the company’s research efforts into the space over the past four decades.

“We continue to work to create broad and simple access to Leqembi for patients and to support diagnosis and treatment at the early stage of the disease,” Naito stated. “Eisai will diligently work to educate physicians on the safe and appropriate use of Leqembi to maximize its benefit to people living with early AD and their families.”

The success of Leqembi marks a significant comeback for Biogen in the Alzheimer’s space following the spectacular rise and fall of Aduhelm. Biogen’s previous leading treatment for the debilitating brain disease started off with promise, gaining accelerated approval from the FDA in June 2021.

However, in May 2022, Biogen punted on launching the drug due to lingering questions around its clinical safety, a decision by the Centers for Medicare and Medicaid Services (CMS) to restrict reimbursement for the drug, (which was initially priced at $56,000 per year), as well as poor sales. 

A subsequent congressional investigation highlighted a series of issues facing the development of the drug, its accompanying marketing plan, its clinical trial diversity and Biogen’s coziness with federal regulators. 

Four months after scuttling Aduhelm’s commercial infrastructure, Biogen released promising data results for what was then called lecanemab. In a Phase 3 trial, the drug met its primary endpoint in showing a “statistically significant” reduction in clinical decline among patients with early Alzheimer’s and met all its secondary endpoints.

“Today marks a breakthrough in the treatment of Alzheimer’s disease, and we are proud to be at the forefront of ushering in a new era of advances for a disease that was previously considered untreatable,” Biogen CEO Christopher A. Viehbacher said in a statement. “We would like to express our sincere appreciation to those who have worked tirelessly to find a treatment for this unrelenting disease, without whom this progress would not be possible.”

Similar to its troubled predecessor Aduhelm, Leqembi still faces a challenge when it comes to federal reimbursement.

A study published in JAMA Internal Medicine earlier this spring concluded that Leqembi could cost Medicare up to $5 billion per year if more than 216,000 beneficiaries are eligible for the treatment. Of note, Leqembi is priced at $26,500 per year, which an industry watchdog concluded is still 19% more than it should be. 

In March, the Veterans Health Administration announced it would cover Leqembi, which made it one of the first federal agencies to back the drug. However, CMS has demurred on loosening the national coverage determination for monoclonal antibodies directed against amyloid for treating Alzheimer’s disease until the FDA announced whether or not it would approve the drug. 

In light of the FDA decision, CMS issued a statement that broader Medicare coverage is now available for Leqembi. To qualify, patients will have to be enrolled in Medicare, diagnosed with mild cognitive impairment or mild Alzheimer’s disease dementia along with evidence of beta-amyloid plaque on the brain, as well as a have physician who participates in a qualifying registry.

“With FDA’s decision, CMS will cover this medication broadly while continuing to gather data that will help us understand how the drug works,” CMS Administrator Chiquita Brooks-LaSure said in a statement. “This is welcome news for the millions of people in this country and their families who are affected by this debilitating disease.”

In addition to patients, most healthcare professionals (HCP) have been eagerly awaiting the arrival of Leqembi through the traditional approval process.

A recent survey from Sermo found that 81% supported the drug’s full approval by the FDA, with 90% stating that Leqembi gives hope to patients living with Alzheimer’s. Still, 85% of respondents indicated that they had concerns about side effects from the drug, including the potential for amyloid-related imaging abnormalities, a type of brain bleeding and swelling.

Industry stakeholders, including the Alzheimer’s Association, applauded the FDA’s landmark decision, which comes after years of research and lobbying on behalf of patients.

“We appreciate today’s action by CMS and their efforts to reduce physician burden in their registry approach. It is clear that CMS leaders have listened to experts, advocates, people living with Alzheimer’s and families,” Alzheimer’s Association CEO Joanne Pike, DrPH said in a statement. “It is reflected in their plan for delivering coverage of traditionally approved treatments proven to deliver meaningful benefit.”

Howard Fillit, MD, co-founder and chief science officer of the Alzheimer’s Drug Discovery Foundation, commended the decision as “encouraging news” while also noting that Leqembi will bolster research efforts into the disease.

“Now, it is more important than ever to double down and widen our focus to developing the next generation of drugs based on the biology of aging that can lead to a combination therapy and precision medicine approach,” Fillit said in a statement.

George Vradenburg, chairman and co-founder of UsAgainstAlzheimer’s, called on CMS to expand access to the drug, noting that registries “everely limited patient access” and place additional burdens on HCPs.

“Leqembi’s traditional approval is a ray of hope for millions of patients who are doing everything in they can to enhance and extend their lives and reduce their families’ burdens,” Vradenburg said in a statement. “People with early-stage disease now have a weapon to fight Alzheimer’s. Finally, we have a drug that can slow the encroachment of Alzheimer’s into our families’ lives and livelihoods.

This story has been updated with additional commentary.