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): August 29, 2018

EXPRESS SCRIPTS HOLDING COMPANY

(Exact Name of Registrant as Specified in its Charter)

Registrant’s telephone number including area code: 314-996-0900

No change since last report

(Former Name or 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  ☐

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.  ☐

Cigna Corporation (“Cigna”) disclosed that its officials expect to participate in meetings with investors and analysts over the next several weeks. During these meetings, Cigna officials expect to provide an update related to federal and state regulatory approvals for Cigna’s pending acquisition of Express Scripts Holding Company (“Express Scripts”).

As previously announced, on March 8, 2018, Cigna, Express Scripts and certain of Cigna’s affiliates entered into a definitive agreement whereby Cigna will acquire Express Scripts. Completion of the transaction is subject to the satisfaction or (where permissible) waiver of certain closing conditions, including: (1) the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”); and (2) certain state regulatory approvals (in the case of (1) and (2), without the imposition, individually or in the aggregate, of certain restrictions or conditions).

Related to federal regulatory approval, Cigna and Express Scripts filed notification and report forms in connection with the transaction with the U.S. Department of Justice (the “DOJ”) and the U.S. Federal Trade Commission pursuant to the HSR Act on March 22, 2018. As previously disclosed, on April 23, 2018, Cigna and Express Scripts each received a request for additional information and documentary material (the “Second Request”) from the DOJ in connection with the DOJ’s review of the transaction.

On July 5, 2018, the parties entered into a timing agreement with the DOJ pursuant to which they agreed, among other things, not to close their pending combination before 12:01AM Eastern Time on the ninetieth (90th) calendar day following the date on which both Cigna and Express Scripts have certified substantial compliance with the DOJ’s Second Request, unless: (1) the parties have received notice from the DOJ that it has closed its investigation; or (2) the parties and the DOJ mutually agree to extend the 90 day timeframe. Timing agreements with the DOJ are customary in large transactions of this nature.

On August 3, 2018, Cigna certified substantial compliance with the Second Request. Express Scripts certified substantial compliance with the Second Request on August 17, 2018.

Related to state regulatory approvals, certain state insurance regulators have the authority to approve a “change of control” of an insurer. Cigna has filed “Form A” statements (or equivalent change of control applications) and/or requests for exemptions from the Form A application requirements in each jurisdiction where required by applicable law (“states”). Currently, Cigna has received approvals from 14 states. Approvals from 15 additional states are conditions to closing the transaction.

In addition to the above, there are certain additional state and international regulatory approvals and filings required in connection with the proposed transaction.

Express Scripts continues to anticipate that the merger will close by year-end 2018, subject to the satisfaction of all closing conditions, and looks forward to continuing to work cooperatively with the DOJ and the relevant states to discuss the many benefits of the transaction.

Cautionary Notes on Forward Looking Statements

This communication contains statements which, to the extent they are not statements of historical or present fact, constitute “forward-looking statements” under the securities laws. These forward-looking statements are intended to provide Cigna management’s and/or Express Scripts management’s current expectations or plans for future operating and financial performance, based on assumptions currently believed to be valid. Forward-looking statements can be identified by the use of words such as “believe,” “expect,” “expectations,” “plans,” “strategy,” “prospects,” “estimate,” “project,” “target,” “anticipate,” “will,” “may,” “should,” “see,” “guidance,” “confident” and other words of similar meaning in connection

with a discussion of future operating or financial performance. Forward-looking statements may include, among other things, statements relating to future sales, earnings, cash flow, results of operations, uses of cash, share repurchases and other measures of financial performance or potential future plans, strategies or transactions of Cigna or the combined company following consummation of the mergers, the anticipated benefits of the mergers, including estimated synergies, the expected timing of completion of the mergers, Cigna’s ability to obtain financing for the mergers and other statements that are not historical facts. All forward-looking statements involve risks, uncertainties and other factors that may cause actual results to differ materially from those expressed or implied in the forward-looking statements. For those statements, Cigna and Express Scripts claim the protection of the safe harbor for forward-looking statements contained in the U.S. Private Securities Litigation Reform Act of 1995. Risks, uncertainties and other factors that could cause actual results to differ from these forward-looking statements include, but are not limited to, risks and uncertainties detailed in Cigna’s and Express Scripts’ periodic public filings with the SEC, including those discussed in the section entitled “Risk Factors” of the registration statement and in the sections entitled “Risk Factors” in Cigna’s Annual Report on Form 10-K for the year ended December 31, 2017, Cigna’s Quarterly Report on Form 10-Q for the period ended June 30, 2018, Express Scripts’ Annual Report on Form 10-K for the year ended December 31, 2017 and Express Scripts’ Quarterly Report on Form 10-Q for the period ended June 30, 2018, factors contained or incorporated by reference into such documents and in subsequent filings by Cigna and Express Scripts, and the following factors:

There can be no assurance that the mergers or any other transaction described in this joint proxy statement/prospectus will in fact be completed in the manner described or at all. Any forward-looking statement speaks only as of the date on which it is made, and Cigna and Express Scripts assume no obligation to update or revise such statement, whether as a result of new information, future events or otherwise, except as required by applicable law. Readers are cautioned not to place undue reliance on any of these forward-looking statements.

SIGNATURE

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 thereunto duly authorized.