Lundbeck, a global drugmaker based in Denmark, has agreed to buy La Jolla-based Longboard Pharmaceuticals for $2.6 billion to gain access to its novel epilepsy drug.

The acquisition announced Monday will expand Lundbeck’s existing portfolio of treatments for neurological conditions such as Parkinson’s disease, post-traumatic stress disorder and migraines. Lundbeck, which also manufactures the drug Lexapro, focuses on treatments for brain disorders.

Longboard’s lead drug candidate, bexicaserin, is an oral medication that could potentially treat seizures associated with rare forms of epileptic disorders. The novel drug is a superagonist — which is a chemical that binds to certain cell receptors and blocks a response from the body — targeting 5-HT2C receptors.

It has received “breakthrough therapy designation” from the U.S. Food and Drug Administration, which is an expedited development process to advance promising medicines that could be better than available treatments.

Bexicaserin is currently undergoing a global phase three clinical trial and is expected to launch at the end of 2028, according to the company. Lundbeck is projecting global sales potential for the drug at $1.5 billion to $2 billion.

The acquisition of Longboard — which was approved by both company’s boards — is expected to close by the end of this year. It is the largest deal in Lundbeck’s history, according to Reuters.

“This transformative transaction will become a cornerstone in Lundbeck’s neuro-rare franchise, with a potential to drive growth into the next decade,” said said Charl van Zyl, president and CEO of Lundbeck. “Bexicaserin addresses a critical unmet need for patients suffering from rare and severe epilepsies, for which there are very few good treatment options available.”

Lundbeck will pay a premium for Longboard’s stock — about $60 per share in cash.

The local company’s stock closed Friday at $38.90 per share, and spiked 51 percent on the news. It closed Monday at $58.99 per share on the Nasdaq Global Market.

“Lundbeck’s remarkable capabilities will accelerate our vision to provide increased equity and access for underserved (Developmental and Epileptic Encephalopathies) patients with significant unmet medical needs,” said Kevin R. Lind, president and CEO of Longboard in the announcement.

The local company is also developing a phase one treatment that seeks to modulate the receptors associated with neurological diseases such as, multiple sclerosis, lupus, Parkinson’s disease and Alzheimer’s disease.

Longboard was founded in 2020 by Arena Pharmaceuticals, another San Diego biopharma company that was later acquired by Pfizer. A year later, Longboard entered the public market through an approximately $80 million initial public offering.

The company has 50 full-time employees as of Feb. 29, according to Longboard’s SEC filing.

Lundbeck has approximately 1,000 employees in the United States, including staff at the Lundbeck La Jolla Research Center, just off North Torrey Pines Road.