Xenon Pharmaceuticals Inc. (Nasdaq: XENE), a clinical stage biopharmaceutical company, today announced that it has commenced an underwritten public offering of $250 million of its common shares pursuant to its existing shelf registration statement. It is expected that the underwriters of the offering will be granted an option for a period of 30 days to purchase up to an additional $37.5 million of common shares at the public offering price, less the underwriting discounts and commissions. The offering is subject to market and other conditions, and there can be no assurance as to whether or when the offering may be completed.

Jefferies, SVB Leerink, Stifel and RBC Capital Markets are acting as joint book-running managers for the offering.