FOURTH AMENDMENT TO EMPLOYMENT AGREEMENT

Exhibit 10.4

FOURTH AMENDMENT TO EMPLOYMENT AGREEMENT

This Fourth Amendment to Employment Agreement (“Fourth Amendment”), effective as of April 4, 2017 (the “Effective Date”) is entered into by and between ArQule, Inc., a Delaware corporation (the “Company”) with its principal offices at One Wall Street, Burlington, Massachusetts 01803, and Brian Schwartz (“Executive”). The purpose of this Fourth Amendment is to amend the employment agreement dated as of June 17, 2008 between the Company and Executive, as previously amended (the “Employment Agreement”). Capitalized terms used but not defined in this Fourth Amendment shall have the meanings ascribed to them in the Employment Agreement.

In consideration of the mutual covenants and agreements contained herein and for other good and valuable consideration, the receipt, adequacy and sufficiency of which are hereby acknowledged, the Company and Executive (collectively, the “Parties”) hereby agree as follows:

“The Company hereby agrees to continue to employ Executive, and Executive hereby accepts such continued employment with the Company, upon the terms and subject to the conditions set forth in the Employment Agreement. The Parties agree that the employment term shall continue through April 4, 2020, unless earlier terminated in accordance with the provisions of Section 5 of the Employment Agreement (the “Employment Term”).

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IN WITNESS WHEREOF, the Parties have executed or caused to be executed this Amendment as of the date set forth above.