Kastle Therapeutics has acquired global rights to develop and commercialize the marketed drug Kynamro® (mipomersen sodium) injection from Ionis Pharmaceuticals for up to $95 million-plus.
Kynamro is indicated as a treatment for a rare form of high cholesterol, homozygous familial hypercholesterolemia (HoFH).
The deal marks Kastle’s first acquisition since it was formed last year. Kastle focuses on acquiring, developing, and commercializing pharmaceuticals targeted toward diseases with high unmet medical needs.
“Kynamro fits our strategy perfectly,” Kastle President Bryan Stuart said in a statement. “With Kynamro, Kastle aims to bring an established rare disease therapy to more patients in the U.S. and other regions through the pursuit of additional indications and regulatory approvals worldwide.”
Ionis—which changed its name in December 2015 from Isis Pharmaceuticals—had been seeking a commercialization alternative since January, when it terminated its license agreement with Sanofi, a Genzyme Company, to co-market Kynamro: “We’ve been disappointed with the performance of Genzyme for quite a while,” Ionis CBO Sarah Boyce told the San Diego Union-Tribune at the time.
In today’s statement, Boyce added that Kastle has begun initiatives to identify new patients to bring onto therapy in the U.S. and plans to pursue marketing approval in other countries.
“We believe Kastle Therapeutics has the expertise, financial resources, and initiative to maximize the commercial value of Kynamro,” Boyce said. “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.”
Kynamro is indicated as an adjunct to lipid-lowering medications and diet to reduce low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apo B), total cholesterol (TC), and non-high-density lipoprotein cholesterol (non HDL-C) in patients with HoFH.
Kynamro is designed to work by reducing LDL-C through prevention of the formation of atherogenic lipoproteins. Kynamro blocks the production of apo B, the protein that provides the structural core for LDL and other atherogenic particles.
Kastle agreed to pay Ionis $15 million upfront, another $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.
However, 3% of the cash payments that Ionis receives from Kastle—up to $2.85 million—plus a 3% royalty on Kynamro sales—will be earned by Genzyme.