Basis of Presentation

3 Months Ended

Mar. 31, 2017

We prepared the unaudited interim condensed consolidated financial statements for the three months ended March 31, 2017 and 2016 on the same basis as the audited financial statements for the year ended December 31, 2016. We included all normal recurring adjustments in the financial statements, which we considered necessary for a fair presentation of our financial position at such dates and our operating results and cash flows for those periods. Results for the interim periods are not necessarily indicative of the results for the entire year. For more complete financial information, these financial statements, and notes thereto, should be read in conjunction with the audited financial statements for the year ended December 31, 2016 included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission, or SEC.

In the condensed consolidated financial statements we included the accounts of Ionis Pharmaceuticals, Inc. and our wholly owned subsidiary, Akcea Therapeutics, Inc., which we formed in December 2014 and its wholly owned subsidiaries, Akcea Therapeutics UK Ltd, which Akcea formed in August 2016 and Akcea Intl Ltd., which Akcea formed in February 2017. Unless the context requires otherwise, “Ionis”, “Company,” “we,” “our,” and “us” refers to Ionis Pharmaceuticals, Inc. and its wholly owned subsidiary, Akcea Therapeutics, Inc.