Sanofi commences tender offer for acquisition of Synthorx, Inc.

PARIS – December 23, 2019 – Sanofi announced today that it intends to commence a tender offer (the “Offer”) today to acquire all of the outstanding shares of common stock of Synthorx, Inc. (“Synthorx”) for $68 per share in cash, without interest thereon and net of any applicable withholding taxes.

The Offer is being made pursuant to the Agreement and Plan of Merger, dated as of December 7, 2019 (as it may be amended from time to time, the “Merger Agreement”), by and among Synthorx, Sanofi and Thunder Acquisition Corp., a Delaware corporation and an indirect, wholly-owned subsidiary of Sanofi (“Purchaser”).

The Offer is scheduled to expire one minute past 11:59 p.m., Eastern Time, on Wednesday, January 22, 2020, unless the Offer is extended in accordance with the Merger Agreement and the applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”).

The consummation of the Offer is subject to customary closing conditions, including the tender of at least a majority of the outstanding shares of Synthorx common stock, the expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, and other customary conditions. Following the successful completion of the Offer, Purchaser will merge with and into Synthorx pursuant to Section 251(h) of the General Corporation Law of the State of Delaware, with Synthorx continuing as the surviving corporation and becoming an indirect, wholly-owned subsidiary of Sanofi (the “Merger”). At the effective time of the Merger, the outstanding shares of common stock of Synthorx not tendered in the Offer will be converted into the right to receive the same $68 per share in cash that they would have received had they tendered their shares in the Offer.

Sanofi and Purchaser intend to commence the Offer by filing with the SEC a tender offer statement on Schedule TO. Synthorx intends to file a Solicitation/Recommendation Statement on Schedule 14D-9 with the SEC with respect to the Offer. Synthorx stockholders are urged to carefully read the relevant tender offer materials (including the offer to purchase, the related letter of transmittal and the other tender offer documents when they become available), and the Solicitation/Recommendation Statement on Schedule 14D-9 once it is available, because they contain important information that Synthorx stockholders should consider before making any decision regarding tendering their shares. The Offer to Purchase, the related Letter of Transmittal and certain other tender offer documents, will be available to all holders of Synthorx stock at no expense to them. The tender offer materials will be available for free at the SEC’s web site at www.sec.gov. Additional copies may be obtained for free by contacting Sanofi at ir@sanofi.com or on Sanofi’s website at https://en.sanofi.com/investors.

Morgan Stanley & Co. is acting as financial advisor to Sanofi and Weil, Gotshal & Manges LLP is acting as its legal counsel. Centerview Partners LLC is acting as exclusive financial advisor to Synthorx and Cooley LLP is acting as its legal counsel.