Exhibit 3.1

AMENDED AND RESTATED

CERTIFICATE OF INCORPORATION

OF

HARPOON THERAPEUTICS, INC.

FIRST: The name of the corporation is Harpoon Therapeutics, Inc. (hereinafter, the “Corporation”).

SECOND: The address of the Corporation’s registered office in the State of Delaware is Corporation Trust Center, 1209 Orange Street, Wilmington, New Castle County, Delaware 19801, and the name of its registered agent at such address is The Corporation Trust Company.

THIRD: The purpose of the Corporation is to engage in any lawful act or activity for which a corporation may be organized under the Delaware General Corporation Law (“DGCL”).

FOURTH: The total number of shares of stock which the Corporation shall have authority to issue is 1,000 shares of common stock, par value $0.001 per share.

FIFTH: The business and affairs of the Corporation shall be managed by or under the direction of the board of directors, and the directors need not be elected by ballot unless required by the bylaws of the Corporation.

SIXTH: In furtherance and not in limitation of the powers conferred by the laws of the State of Delaware, the board of directors is expressly authorized to make, amend or repeal the bylaws or adopt new bylaws without any action on the part of the stockholders of the Corporation; provided that any by-law adopted or amended by the board of directors, and any powers thereby conferred, may be amended, altered or repealed by the stockholders of the Corporation.

SEVENTH: The liability of the directors for monetary damages shall be eliminated to the fullest extent under applicable law. To the fullest extent permitted by applicable law, the Corporation is authorized to provide indemnification of (and advancement of expenses to) directors, officers and agents of the Corporation (and any other persons to which applicable law permits the Corporation to provide indemnification) through bylaw provisions, agreements with such agents or other persons, vote of stockholders or disinterested directors or otherwise in excess of the indemnification and advancement otherwise permitted by such applicable law. If applicable law is amended after the date of filing of this Certificate of Incorporation, to authorize corporate action further eliminating or limiting the personal liability of directors, then the liability of a director to the Corporation shall be eliminated or limited to the fullest extent permitted by applicable law as so amended. Any repeal or modification of this Article Seventh shall only be prospective and shall not affect the rights or protections or increase the liability of any director under this Article Seventh in effect at the time of the alleged occurrence of any act or omission to act giving rise to liability or indemnification.

EIGHTH: The Corporation reserves the right to amend and repeal any provision contained in this Certificate of Incorporation in the manner from time to time as prescribed by the laws of the State of Delaware. All rights herein conferred are granted subject to this reservation.

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