Basis of Presentation (Policies)

9 Months Ended

Sep. 30, 2018

Basis of Presentation [Abstract]

Basis of Presentation

We prepared the unaudited interim condensed consolidated financial statements for the three and nine months ended September 30, 2018 and 2017 on the same basis as the audited financial statements for the year ended December 31, 2017. 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, 2017 included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission, or SEC.

Consolidation

In the condensed consolidated financial statements, we included the accounts of Ionis Pharmaceuticals, Inc. and the consolidated results of our majority owned affiliate, Akcea Therapeutics, Inc. and its wholly owned subsidiaries, which we formed in December 2014. Prior to Akcea’s initial public offering, or IPO, in July 2017, we owned 100 percent of Akcea. From the closing of Akcea’s IPO in July 2017 through mid-April 2018, we owned approximately 68 percent of Akcea. In the second and third quarters of 2018, we received additional shares of Akcea’s stock related to our license of TEGSEDI and AKCEA-TTR-L_Rx to Akcea, increasing our ownership percentage to approximately 75 percent. We reflected the increase in our ownership in these financial statements. In October 2018, we received an additional 1.7 million shares of Akcea’s stock when TEGSEDI received marketing authorization in the U.S., increasing our ownership to approximately 76 percent. Refer to the section titled “Noncontrolling Interest in Akcea” in Note 2, Significant Accounting Policies, for further information related to our accounting for our investment in Akcea.