Apellis and Sobi have amended their partnership agreement for paroxysmal nocturnal hemoglobinuria (PNH) treatment Empaveli, or Aspaveli as it is known in Europe.

With the new deal, Stockholm-based Sobi will pay $275 million upfront and up to $25 million in potential milestones to reduce its ex-U.S. royalty obligations on Aspaveli. The milestones are tied to potential European Medicines Agency approval for Aspaveli to treat two rare kidney diseases—complement 3 glomerulopathy (C3G) and primary immune complex membranoproliferative glomerulonephritis (IC-MPGN).

Under the companies’ 2020 collaboration, Massachusetts-based Apellis was eligible for tiered royalties ranging from the high-teen-percentages to the low 20s based on sales of Aspaveli outside of the U.S. The new deal doesn’t affect Apellis’ exclusive commercialization rights for the product in the U.S.

The agreement is subject to defined caps tied to the performance of Aspaveli. Under the new deal, Sobi reduces its royalty obligations by 90% until these caps are reached. Afterward, the ex-U.S. royalty level returns to the parameters outlined in the pair's original agreement.

Empaveli generated $98 million in U.S. sales last year, an increase from $91 million in 2023. Sobi reported sales of Aspaveli at 333 million Swedish krona ($35 million) last year.

Apellis' top product is geographic atrophy drug Syfovre, which generated $612 million in sales in 2024, more than double its $275 million haul in 2023.

Apellis believes that Empaveli has blockbuster potential after posting “unprecedented” phase 3 results in C3G and IC-MPGN, according to Apellis CEO Cedric Francois, M.D., Ph.D. 

Analysts from Evercore and Mizuho Securities praised Apellis' move, with Evercore writing: "We like this deal. It undercuts a major source of investor nervousness coming into C3G launch (cash balance) without costing Apellis much in long-term value."

Evercore also noted a 2% share price increase for Apellis on Tuesday.

Related

Apellis Pharma and its rare disease, eyecare drugs draw takeover interest: Bloomberg

“We view this as a net positive for Apellis, as it not only strengthens the company’s balance sheet, it provides a key source of non-dilutive funding—for a company that, at least on our current projections, is not expected to turn profitable until 2029,” Mizuho's analysts added. “Given a slower than expected uptake for Syfovre (and a slower time to company profitability), we’re not surprised to see Apellis proactively address its balance sheet needs.”

The FDA is scheduled to render a decision on Empaveli in the C3G and IC-MPGN indications on July 28. Europe’s Committee for Medicinal Products for Human Use (CHMP) is expected to decide on Aspaveli in the indications by the end of this year.

“We are confident in our ability to reach patients with C3G and IC-MPGN globally following regulatory approvals, by leveraging our broad commercial footprint, deep rare disease expertise, and proven success in PNH,” Guido Oelkers, Sobi’s CEO, said in a release.