Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The principal accounting policies applied in the preparation of these unaudited condensed consolidated financial statements are described in the Company’s audited financial statements as of and for the year ended December 31, 2021, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on February 28, 2022 (the “Annual Report on Form 10-K”). There have been no material changes in the Company’s significant accounting policies during the six months ended June 30, 2022. Basis of Presentation The Company prepared its unaudited consolidated condensed financial statements in compliance with generally accepted accounting principles in the U.S. ("U.S. GAAP"). Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The unaudited condensed consolidated financial statements include the accounts of Merus N.V. and its wholly owned, controlled subsidiary, Merus US, Inc. All intercompany transactions and balances of subsidiaries have been eliminated in consolidation. In the opinion of management, these financial statements reflect all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the unaudited condensed consolidated financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended June 30, 2022 and 2021 are referred to as the second quarter of 2022 and 2021, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. The unaudited condensed consolidated financial statements presented herein do not contain the required disclosures under U.S. GAAP for annual financial statements. Therefore, these unaudited condensed consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements and related notes as of and for the year ended December 31, 2021, included in the Annual Report on Form 10-K. Going Concern At each reporting period, the Company evaluates whether there are conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. The Company is required to make certain additional disclosures if it concludes substantial doubt exists and it is not alleviated by the Company’s plans or when its plans alleviate substantial doubt about the Company’s ability to continue as a going concern. The Company’s evaluation entails analyzing prospective operating budgets and forecasts for expectations of the Company’s cash needs, and comparing those needs to the current cash, cash equivalent and marketable securities balances. After considering the Company’s current research and development plans, the timing expectations related to the progress of its clinical-stage programs and its plans to pursue commercialization of any approved antibody candidate, and after considering its existing cash, cash equivalents and marketable securities as of June 30, 2022, the Company did not identify conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year from the date these financial statements were issued. Additional details of the Company’s cash runway are described in Note 1 Overview. New Accounting Pronouncements The Company considers the applicability and impact of any recent Accounting Standards Update ("ASU") issued by the Financial Accounting Standards Board ("FASB"). Based on the assessment, the ASUs were determined to be either not applicable or are expected to have minimal impact on the Company's condensed consolidated financial statements.

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2022

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The principal accounting policies applied in the preparation of these unaudited condensed consolidated financial statements are described in the Company’s audited financial statements as of and for the year ended December 31, 2021, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on February 28, 2022 (the “Annual Report on Form 10-K”). There have been no material changes in the Company’s significant accounting policies during the six months ended June 30, 2022.

Basis of Presentation

The Company prepared its unaudited consolidated condensed financial statements in compliance with generally accepted accounting principles in the U.S. ("U.S. GAAP"). Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB").

The unaudited condensed consolidated financial statements include the accounts of Merus N.V. and its wholly owned, controlled subsidiary, Merus US, Inc. All intercompany transactions and balances of subsidiaries have been eliminated in consolidation. In the opinion of management, these financial statements reflect all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the unaudited condensed consolidated financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended June 30, 2022 and 2021 are referred to as the second quarter of 2022 and 2021, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.

The unaudited condensed consolidated financial statements presented herein do not contain the required disclosures under U.S. GAAP for annual financial statements. Therefore, these unaudited condensed consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements and related notes as of and for the year ended December 31, 2021, included in the Annual Report on Form 10-K.

Going Concern

At each reporting period, the Company evaluates whether there are conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. The Company is required to make certain additional disclosures if it concludes substantial doubt exists and it is not alleviated by the Company’s plans or when its plans alleviate substantial doubt about the Company’s ability to continue as a going concern.

The Company’s evaluation entails analyzing prospective operating budgets and forecasts for expectations of the Company’s cash needs, and comparing those needs to the current cash, cash equivalent and marketable securities balances. After considering the Company’s current research and development plans, the timing expectations related to the progress of its clinical-stage programs and its plans to pursue commercialization of any approved antibody candidate, and after considering its existing cash, cash equivalents and marketable securities as of June 30, 2022, the Company did not identify conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year from the date these financial statements were issued. Additional details of the Company’s cash runway are described in Note 1 Overview.

New Accounting Pronouncements

The Company considers the applicability and impact of any recent Accounting Standards Update ("ASU") issued by the Financial Accounting Standards Board ("FASB"). Based on the assessment, the ASUs were determined to be either not applicable or are expected to have minimal impact on the Company's condensed consolidated financial statements.