Exhibit 23.1​

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (File Nos. 333-198884, 333-198883, 333-178228, 333-178227, 333-178226, and 333-130159) and on Form S-3 (File Nos. 333-221926 and 333-213456) of ArQule, Inc., of our report dated March 5, 2018 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts
March 5, 2018