Eton Pharmaceuticals launched IMPAVIDO (miltefosine) capsules in the United States on Sept. 28, beginning commercial sales under exclusive U.S. rights secured earlier this year from an affiliate of Knight Therapeutics. The launch was disclosed in a Form 8-K filed with the Securities and Exchange Commission and marks Eton’s addition of the orphan drug to its commercial portfolio.
Eton’s exclusive U.S. commercialization rights took effect Sept. 26 under a supply and distribution agreement signed May 18. The company said the launch incorporates IMPAVIDO into its existing rare-disease commercial infrastructure, including Eton Cares patient support and centralized distribution through Anovo Specialty Pharmacy.
IMPAVIDO is an FDA-approved oral treatment for certain forms of leishmaniasis, a parasitic disease. The drug is indicated for visceral leishmaniasis caused by Leishmania donovani, specified forms of cutaneous leishmaniasis and mucosal leishmaniasis caused by Leishmania braziliensis in adults and adolescents at least 12 years old and weighing at least 30 kilograms.
The commercial arrangement carries $4.25 million in fixed fees during its initial term, which runs through March 31, 2032. Eton is scheduled to make payments of $125,000 in July 2026, $1.25 million in April 2027, $1 million each in June 2028 and June 2029, and $875,000 in June 2030.
Eton can also owe up to $4 million in additional payments if cumulative net sales reach $50 million, $100 million, $150 million and $200 million. Under the agreement, Eton will pay the supplier 55% of annual net sales up to $7 million and 50% of annual net sales above that level, while the supplier remains responsible for product and regulatory costs and Eton covers sales and marketing expenses.
The economics give Eton a relatively limited fixed commitment compared with a traditional acquisition, but the company will share a substantial portion of product revenue with the supplier. Eton previously disclosed that IMPAVIDO generated $8.1 million in U.S. sales during 2025, according to Symphony Health data.
The company said IMPAVIDO has been commercially available in the United States since 2016, meaning Eton’s move represents a change in commercial responsibility rather than a new regulatory approval for the drug. Eton said it plans to expand hospital on-site availability through consignment inventory and will use Anovo to coordinate urgent access for time-sensitive patient needs.
The launch adds to Eton’s broader expansion of its rare-disease portfolio. In August, the company reported second-quarter 2026 product sales of $37.6 million, up 99% from a year earlier, and raised its full-year revenue outlook to more than $145 million. At that time, Eton said it expected to begin commercializing IMPAVIDO in September.
Eton has described the product as complementary to its orphan-drug commercialization model, while its second-quarter management commentary indicated that IMPAVIDO was expected to contribute multiple millions of dollars annually once commercialized. The company also noted that the product’s margin would be lower than some of its other products because of the revenue-sharing structure.
IMPAVIDO’s launch adds another established therapy to Eton’s commercial portfolio without requiring the company to fund the product’s manufacturing and regulatory costs. The company will instead bear the U.S. sales and marketing costs and retain the commercial economics remaining after contractual payments to the supplier.
