Eton (NASDAQ: ETON) secures LIBERVANT license with milestones up to $47.5 million

What happened

Eton Pharmaceuticals, Inc. (NASDAQ: ETON) signed an exclusive U.S. license and supply agreement with Aquestive Therapeutics, Inc. on October 13, 2026. The deal gives Eton the right to sell LIBERVANT (diazepam) buccal film in the U.S. for acute seizure clusters in patients with epilepsy, subject to regulatory approvals. LIBERVANT has tentative approval from the U.S. Food and Drug Administration for patients age 2 to 5 and ages 12 and older. It also has Orphan Drug Designation.

Eton paid a $10.0 million upfront license fee. It also owes up to $47.5 million in regulatory and commercial milestones, plus mid-teens royalties on annual net sales. Aquestive will be the exclusive manufacturer and supplier under a 20-year supply agreement.

Key numbers

Metric	Latest	Change	Source
Upfront license fee	$10.0 million		SEC 8-K
Milestone payments	up to $47.5 million		SEC 8-K
First U.S. commercial sale milestone	$10.0 million		SEC 8-K
FDA approval milestone for ages 6 to 11	$2.5 million		SEC 8-K
U.S. seizure rescue market opportunity	exceeds $450 million annually		Press release
Patient preference for buccal film	71%		Press release

Read more: Eton Pharmaceuticals (ETON) stock analysis and investment case

Why it matters

OptimistFi's case is that Eton works if its rare-disease platform keeps turning niche products into profitable growth faster than launch costs erode the economics. This deal adds a neurology asset and, according to the press release, broadens the rare-disease portfolio and gives Eton a new commercial platform.

The release also says LIBERVANT offers an alternative to existing nasal and rectal seizure rescue treatments. Patient research cited in the release found 71% preferred the film versus 13% for nasal spray, assuming equivalent efficacy. The $10.0 million upfront fee is about 21.1% of the $47.5 million milestone cap. Commercial availability is only anticipated in April 2027, subject to final FDA approval.

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What's next

Eton expects commercial availability in April 2027, subject to final FDA approval. The Type 9 NDA to add ages 6 to 11 has a PDUFA target action date of March 29, 2027.

Approval by then would trigger the $2.5 million milestone and support the broader label. A delay or denial would push that payment out. The first U.S. commercial sale would trigger $10.0 million, or $5.0 million if full FDA approval for ages 2 to 5 has not been received.

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