Xenon Pharmaceuticals Announces Pricing of Upsized $650.0 Million Public Offering

VANCOUVER, British Columbia and BOSTON, March 10, 2026 (GLOBE NEWSWIRE) -- Xenon Pharmaceuticals Inc. (Nasdaq: XENE), a neuroscience-focused biopharmaceutical company dedicated to drug discovery, clinical development and commercialization of life-changing therapeutics for patients in need, today announced the pricing of its upsized underwritten public offering of 10,526,317 common shares and, in lieu of common shares to certain investors, pre-funded warrants to purchase up to 877,194 common shares pursuant to its existing shelf registration statement. The common shares are being offered at a public offering price of $57.00 per common share and the pre-funded warrants are being offered at a price of $56.9999 per pre-funded warrant. The gross proceeds to Xenon from the offering, before deducting underwriting discounts and commissions and other offering expenses payable by Xenon, are expected to be approximately $650.0 million. In addition, Xenon has granted to the underwriters of the offering an option for a period of 30 days to purchase up to an additional 1,710,526 common shares at the public offering price, less the underwriting discounts and commissions. The offering is expected to close on or about March 12, 2026, subject to the satisfaction of customary closing conditions.

J.P. Morgan, Jefferies, TD Cowen, Stifel, RBC Capital Markets, and William Blair are acting as joint book-running managers for the offering. Baird is acting as lead manager for the offering.

No securities are being offered or sold, directly or indirectly, in Canada or to any resident of Canada.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy the securities being offered, nor shall there be any sale of the securities being offered in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or other jurisdiction.

About Xenon Pharmaceuticals Inc.

Xenon Pharmaceuticals (Nasdaq: XENE) is a neuroscience-focused biopharmaceutical company dedicated to drug discovery, clinical development and commercialization of life-changing therapeutics for patients in need. Xenon’s lead molecule, azetukalner, is a novel, potent K

7 potassium channel opener in Phase 3 clinical trials for the treatment of epilepsy, major depressive disorder (MDD) and bipolar depression (BPD). Xenon is also advancing an early-stage portfolio of multiple promising potassium and sodium channel modulators, including K 7 and Na 1.7 programs in Phase 1 development for the potential treatment of pain. Xenon has offices in Vancouver, British Columbia, and Boston, Massachusetts.

Xenon and the Xenon logo are registered trademarks or trademarks of Xenon Pharmaceuticals Inc. in the US, Canada, and elsewhere. All other trademarks belong to their respective owner.

Source: Xenon Pharmaceuticals Inc.