- Strengthens Sanofi’s R&D strategy with innovative Nanobody® technology platform
- Expands growing rare blood disorders franchise with Ablynx’s late-stage investigational
caplacizumab aTTP treatment
- Unanimously approved by Sanofi and Ablynx Boards of Directors

PARIS, France and GHENT, Belgium, 29 January 2018 – Sanofi [Euronext: SAN; NYSE: SNY] and Ablynx [Euronext Brussels and Nasdaq: ABLX], a biopharmaceutical company engaged in the discovery and development of Nanobodies®, entered into a definitive agreement under which Sanofi will offer to acquire
all of the outstanding ordinary shares, including shares represented by American Depositary Shares (ADSs), warrants and convertible bonds of Ablynx at a price per Ablynx share of €45 in cash, which represents an aggregate equity value of approximately €3.9 billion. The transaction was unanimously
approved by both the Sanofi and Ablynx Boards of Directors.
Sanofi’s Chief Executive Officer Olivier Brandicourt commented, “With Ablynx, we continue to advance the strategic transformation of our Research and Development, expanding our late-stage pipeline and strengthening our platform for growth in rare blood disorders. This acquisition builds on a successful
existing partnership. We are also pleased to reaffirm our commitment to Belgium, where we have invested significantly over the years in our state-of-the-art biologics manufacturing facility in Geel. We intend to
maintain and support the Ablynx science center in Ghent.”

Ablynx’s Chief Executive Officer Edwin Moses noted, “Since our founding in 2001, our team has been focused on unlocking the power of our Nanobody technology for patients. The results of our work are
validated by clinical data. As we look ahead, we believe Sanofi’s global infrastructure, commitment to innovation and commercial capabilities will accelerate our ability to deliver our pipeline. Our Board of
Directors feels strongly that this transaction represents compelling value for shareholders and maximizes the potential of our pipeline to the benefit of all stakeholders.”

Sustaining Innovation in R&D
The acquisition of Ablynx continues Sanofi’s commitment to breakthrough innovation, focused on technologies addressing multiple disease targets with single multi-specific molecules.
Nanobodies are a novel class of proprietary next generation biologicals. Ablynx is at the leading edge of Nanobody technology supporting a deep pipeline of more than 45 proprietary and partnered candidates for a wide range of therapeutic areas such as hematology, inflammation, immuno-oncology and
respiratory diseases. Eight Nanobodies have entered clinical development.
Sanofi is committed to accelerating development and maximizing the commercial potential of Ablynx’s ongoing and emerging programs.

Strengthening Sanofi’s Platform in Rare Blood Disorders
Ablynx’s most-advanced product in development is caplacizumab (anti-vWF Nanobody), a wholly-owned development program for the treatment of acquired thrombotic thrombocytopenic purpura (aTTP). The
product is already filed in the European Union and expected to be filed in the U.S. during the first half of this year. Caplacizumab, if approved, would be the first-in-class treatment for this acute, life-threatening
disease.
The addition of caplacizumab to Sanofi’s platform strengthens its position in rare blood disorders, complementing the recently announced agreements to acquire Bioverativ and obtain global rights for fitusiran from Alnylam.
Combining Complementary Capabilities to Address Respiratory Syncytial Virus (RSV) Infections Ablynx’s ALX-0171, an inhaled anti-RSV Nanobody, currently in Phase 2b, is a potential breakthrough for the symptomatic treatment of RSV infections—for which there is no widely used therapy available—and
is very complementary to Sanofi Pasteur RSV associated programs.

Delivering Long-Term Shareholder Value
The addition of Ablynx is anticipated to drive meaningful long-term value for Sanofi’s shareholders by enhancing its pipeline and research capabilities. Including R&D expenses, the acquisition is expected to be neutral to Business EPS1 in 2018 and 2019.

Transaction Terms
Under the terms of the agreement, Sanofi will launch public offers to acquire all of the outstanding

ordinary shares (including shares represented by ADSs), warrants and convertible bonds of Ablynx in cash.
Sanofi has complied with the formalities set forth in the Belgian takeover legislation and filed the mandatory documents with the Belgian Financial Services and Markets Authority (FSMA). A notice was
published by the FSMA on its website.
The consummation of the public offers is subject to customary conditions, including the tender of securities representing at least 75% of the outstanding shares of Ablynx at the end of the initial acceptance period of the Belgian Tender Offer, and the receipt of required regulatory approvals. The public offers are expected to be launched by the beginning of the second quarter of 2018.
In accordance with the Belgian requirement of certainty of funds, Sanofi has entered into a bank credit facility, BNP Paribas Fortis SA/NA acting as the sole credit facility arranger. Subject to the satisfaction or waiver of customary closing conditions, the transaction is expected to close by the end of the second quarter 2018.
Morgan Stanley and Lazard are acting as financial advisors to Sanofi. J.P. Morgan is acting as financial advisor to Ablynx. Weil, Gotshal & Manges LLP and NautaDutilh are serving as legal counsels to Sanofi.
Eubelius CVBA, Goodwin Procter LLP and Linklaters LLP are serving as legal counsels to Ablynx.

Sanofi Conference Call
Sanofi will host a webcast live on Sanofi’s website at 2.30pm CET / 8.30am EST on Monday, 29 January 2018. The webcast details and full presentation will be made available on Sanofi’s Investor Relations
webpage.

1Business EPS is a non-GAAP financial measure (see appendix to Sanofi press release on quarterly results for a definition)