Ionis Closes $770 Million Convertible Senior Notes Offering
San Francisco – November 17, 2025 – Cooley advised Ionis Pharmaceuticals, a commercial-stage biotechnology company inventing medicines that bring better futures to people with serious diseases, on its offering of $770 million aggregate principal amount of 0% convertible senior notes due 2030 in a private placement to qualified institutional buyers, pursuant to Rule 144A under the Securities Act of 1933, as amended, which includes the initial purchasers’ option to purchase an additional $70 million aggregate principal amount of notes.
The Cooley team advising Ionis was led by debt finance partners Mischi a Marca and Jason Savich, and capital markets partners Carlos Ramirez and Charlie Kim, with support from associates Winda Fung, Nicholaus Johnson, Jesse Schulman, Xueqing Li and Allie Pilmer.
Cooley previously advised Ionis on its $500.3 million underwritten public offering of common stock in September 2024, its $575 million convertible senior notes offering in June 2023, and its $1.1 billion royalty sale to Royalty Pharma in January 2023 (consisting of a $500 million upfront payment and up to $625 million in milestones).
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