Basis of Presentation	9 Months Ended
Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	2. Basis of presentation: These unaudited interim consolidated financial statements are presented in U.S. dollars and include the accounts of the Company and its wholly-owned subsidiary, Xenon Pharmaceuticals USA Inc., a Delaware corporation. All intercompany transactions and balances have been eliminated on consolidation. The accompanying unaudited interim consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, these consolidated financial statements do not include all of the information and footnotes required for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements and notes for the year ended December 31, 2023 included in the Company’s 2023 Annual Report on Form 10-K filed with the SEC and with the securities commissions in British Columbia, Alberta and Ontario on February 29, 2024. These unaudited interim consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, which, in the opinion of management, are necessary for a fair presentation of results for the interim periods presented. The results of operations for the three and nine month periods ended September 30, 2024 and 2023 are not necessarily indicative of results that can be expected for a full year. These unaudited interim consolidated financial statements follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company included in the Company’s 2023 Annual Report on Form 10-K for the year ended December 31, 2023, with the exception of the policy described in note 3 below. Correction of prior period error During the quarter ended September 30, 2024, the Company determined that accretion of discounts on marketable securities was incorrectly presented within proceeds from marketable securities as part of net cash provided by investing activities on the consolidated statements of cash flows. As a result, a correction was made to the prior period to reclassify the amount of accretion of discounts on marketable securities within net cash used in operating activities, resulting in an increase in net cash used in operating activities and an increase in net cash provided by investing activities of $5,849 from the amounts that were previously reported. The Company evaluated the materiality of the presentation error, both quantitatively and qualitatively, and concluded it was not material to the consolidated financial statements for any prior period. These presentation changes had no effect on the previously reported consolidated balance sheets, consolidated statements of operations and comprehensive loss, or consolidated statements of shareholders’ equity.

Basis of Presentation

9 Months Ended

Sep. 30, 2024

Basis of presentation:

These unaudited interim consolidated financial statements are presented in U.S. dollars and include the accounts of the Company and its wholly-owned subsidiary, Xenon Pharmaceuticals USA Inc., a Delaware corporation. All intercompany transactions and balances have been eliminated on consolidation.

The accompanying unaudited interim consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, these consolidated financial statements do not include all of the information and footnotes required for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements and notes for the year ended December 31, 2023 included in the Company’s 2023 Annual Report on Form 10-K filed with the SEC and with the securities commissions in British Columbia, Alberta and Ontario on February 29, 2024.

These unaudited interim consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, which, in the opinion of management, are necessary for a fair presentation of results for the interim periods presented. The results of operations for the three and nine month periods ended September 30, 2024 and 2023 are not necessarily indicative of results that can be expected for a full year. These unaudited interim consolidated financial statements follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company included in the Company’s 2023 Annual Report on Form 10-K for the year ended December 31, 2023, with the exception of the policy described in note 3 below.

Correction of prior period error

During the quarter ended September 30, 2024, the Company determined that accretion of discounts on marketable securities was incorrectly presented within proceeds from marketable securities as part of net cash provided by investing activities on the consolidated statements of cash flows. As a result, a correction was made to the prior period to reclassify the amount of accretion of discounts on marketable securities within net cash used in operating activities, resulting in an increase in net cash used in operating activities and an increase in net cash provided by investing activities of $5,849 from the amounts that were previously reported. The Company evaluated the materiality of the presentation error, both quantitatively and qualitatively, and concluded it was not material to the consolidated financial statements for any prior period. These presentation changes had no effect on the previously reported consolidated balance sheets, consolidated statements of operations and comprehensive loss, or consolidated statements of shareholders’ equity.