UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 23, 2014

Versartis, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (650) 963-8580

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:

Spokespersons of Versartis, Inc. (the “Company”) plan to present the information in the presentation poster attached hereto as Exhibit 99.1 at the 16th International Congress of Endocrinology and The Endocrine Society’s 96th Annual Meeting and Expo (ICE/ENDO 2014) in Chicago, IL on June 23, 2014.

The furnishing of the attached presentation is not an admission as to the materiality of any information therein. The information contained in the poster is summary information that is intended to be considered in the context of more complete information included in the Company’s filings with the Securities and Exchange Commission (the “SEC”) and other public announcements that the Company has made and may make from time to time by press release or otherwise. The Company undertakes no duty or obligation to update or revise the information contained in this report, although it may do so from time to time as its management believes is appropriate. Any such updating may be made through the filing of other reports or documents with the SEC, through press releases or through other public disclosures.

The information in this Item 7.01 of this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in any such filing.

On June 23, 2014, the Company announced positive Phase 2a data from its six month clinical trial demonstrating the safety and efficacy of VRS-317 in the treatment of naïve, pre-pubertal children with growth hormone deficiency (GHD). A copy of the press release regarding this announcement, titled “Versartis Presents Positive Six Month VRS-317 Phase 2a Clinical Study Results” is attached as Exhibit 99.2 hereto and is incorporated herein by reference.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

INDEX TO EXHIBITS