Exhibit 3.1

CERTIFICATE OF AMENDMENT OF

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF

VERSARTIS, INC.

Versartis, Inc., a corporation organized and existing under the General Corporation Law of the State of Delaware (the “Company”),

DOES HEREBY CERTIFY:

FIRST: The name of Company is Versartis, Inc.

SECOND: The Board of Directors of the Company, acting in accordance with the provisions of Sections 141 and 242 of the General Corporation Law of the State of Delaware, adopted resolutions amending its Amended and Restated Certificate of Incorporation as follows:

Paragraph A in Article IV shall be deleted and the following paragraphs shall be inserted in lieu thereof:

“A. The Company is authorized to issue two classes of stock to be designated, respectively, “Common Stock” and “Preferred Stock.” The total number of shares that the Company is authorized to issue is 55,000,000 shares. 50,000,000 shares shall be Common Stock, each having a par value of $0.0001. 5,000,000 shares shall be Preferred Stock, each having a par value of $0.0001.

Except as otherwise provided by law, the shares of stock of the Company, regardless of class, may be issued by the Company from time to time in such amounts, for such consideration and for such corporate purposes as the Board of Directors may from time to time determine.

Effective at 12:01 a.m. Eastern Time on the day immediately following the filing of this Certificate of Amendment to the Amended and Restated Certificate of Incorporation (the “Certificate of Amendment”) with the Secretary of State of the State of Delaware (the “Effective Time”), each six (6) shares of Common Stock issued and outstanding prior to the Effective Time shall, automatically and without any action on the part of the respective holders thereof, be combined and converted into one (1) share of Common Stock (the “Reverse Split”). No fractional share shall be issued in connection with the foregoing combination of the shares pursuant to the Reverse Split. The Company will pay in cash the fair value of such fractional shares, without interest and as determined in good faith by the Board of Directors of the Company when those entitled to receive such fractional shares are determined.

The Reverse Split shall occur automatically without any further action by the holders of Common Stock, and whether or not the certificates representing such shares of Common Stock have been surrendered to the Company; provided, however, that the Company shall not be obligated to issue certificates evidencing the shares of Common Stock issuable as a result of the Reverse Split unless the existing certificates evidencing the applicable shares of Common Stock prior to the Reverse Split are either delivered to the Company, or the holder notifies the Company that such certificates have been lost, stolen or destroyed, and executes an agreement satisfactory to the Company to indemnify the Company from any loss incurred by it in connection with such certificates.”

THIRD: Thereafter pursuant to a resolution of the Board of Directors, this Certificate of Amendment was submitted to the stockholders of the Company for their approval, and was duly adopted at a Special Meeting of Stockholders held on October 5, 2018, in accordance with the provisions of Section 242 of the General Corporation Law of the State of Delaware.

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IN WITNESS WHEREOF, the Corporation has caused this Certificate to be signed by its Chief Executive Officer this 15th day of October, 2018.