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): April 18, 2019

CORBUS PHARMACEUTICALS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (617) 963-0100

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company [X]

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. [X]

Item 8.01 Other Events.

On April 18, 2019, Corbus Pharmaceuticals Holdings, Inc. (the “Company”) announced that following a Type C meeting with the U.S. Food and Drug Administration, the Company will change the primary efficacy endpoint of the ongoing RESOLVE-1 Phase 3 trial for systemic sclerosis in the U.S. to the American College of Rheumatology Combined Response Index in diffuse cutaneous Systemic Sclerosis score at Week 52 from the current primary endpoint, change in modified Rodnan Skin core (“mRSS”). In the U.S., trial protocol and the first and third secondary efficacy endpoints of RESOLVE-1 (i.e., changes in Health Assessment Questionnaire - Disability Index and forced vital capacity percent predicted, respectively) remain unchanged. Change in mRSS will become the second secondary efficacy endpoint. The size and duration of the study are not being changed. The Company intends to pursue discussions with other regulatory authorities to consider changing primary efficacy outcome to ACR CRISS outside of the U.S.

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.