Sixth Amendment to Employment Agreement, dated as of March 29, by and between the Company and Brian Schwartz

Exhibit 10.4

FIFTH AMENDMENT TO EMPLOYMENT AGREEMENT

This Fifth Amendment to Employment Agreement (“Fifth Amendment”), effective as of March 29, 2019 (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 Fifth 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 Fifth 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 March 31, 2022, 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 Fifth Amendment as of the date set forth above.