In a deal worth up to $95 million-plus, San Diego drugmaker Ionis Pharmaceuticals sold global rights to develop and commercialize its marketed drug Kynamro to Chicago-based Kastle Therapeutics.

The injectable drug is indicated as a treatment for a rare form of high cholesterol, homozygous familial hypercholesterolemia (HoFH).

Ionis, formerly Isis Pharmaceuticals, had been seeking a commercialization alternative since January, when it terminated its license agreement with Sanofi to co-market Kynamro.

"We believe Kastle Therapeutics has the expertise, financial resources, and initiative to maximize the commercial value of Kynamro,” said Ionis Chief Business Officer Sarah Boyce, in a statement. “Kastle's management team brings expertise in marketing orphan drugs for rare diseases which, combined with its ability to be nimble and focused, has the potential to greatly enhance the Kynamro brand.”

Kastle agreed to pay Ionis $15 million upfront, an additional $10 million due May 3, 2019, and up to $70 million in payments tied to achieving sales milestones. Beginning in 2017, Kastle will pay Ionis royalties on global sales of Kynamro in the mid to low teen percentage range.

Ionis stock trades on Nasdaq under the stock symbol IONS.