PUBLICATION IN ACCORDANCE WITH ARTICLE 14 OF THE BELGIAN LAW OF 2 MAY 2007 REGARDING THE PUBLICATION OF MAJOR SHAREHOLDINGS (THE "TRANSPARENCY LAW") - Seite 2

On 29 January 2018, Sanofi made an offer to acquire all of Ablynx's outstanding ordinary shares (including shares represented by American Depository Shares (ADSs), warrants and convertible bonds (collectively with the outstanding ordinary shares, the "Securities")) at a price of €45 per share, which represents an aggregate equity value of approximately €3.9 billion. The proposed transaction was unanimously approved by both the Sanofi and Ablynx Board of Directors. The offer is comprised of two separate but concurrent tender offers: (i) a tender offer under the laws of Belgium for all of the outstanding shares, warrants and convertible bonds of Ablynx (the "Belgian Offer") and (ii) a tender offer under the laws of the U.S. for all of the outstanding shares held by U.S. holders and ADSs held by holders, wherever located (the "U.S. Offer" and together with the Belgian Offer, the "Offers"). The initial acceptance period of the tender offers commenced on 4 April 2018 and expired at 5:00 p.m. ET / 11:00 p.m. CET on 4 May 2018.

Sanofi confirmed on 14 May 2018 that, as of the expiration of the initial acceptance period, a total of 71,972,994 shares (including 7,446,312 shares represented by ADSs), 2,594,841 warrants and 975 convertible bonds had been validly tendered into the Offers and not withdrawn. Sanofi owns 95.60% of the outstanding shares of Ablynx as of the settlement date of the Offers, of which more than 90% were acquired through the Offers. Sanofi further confirmed that the Minimum Tender Condition and the other conditions to the Offers have been satisfied.

Sanofi has decided to proceed with a squeeze-out of those Securities not tendered to the Offers in accordance with applicable Belgian and U.S. law. In this regard, Sanofi reopened the Offers and commenced the squeeze-out period on May 22, 2018, to acquire those Securities not previously tendered into the Offers. The squeeze-out period will expire on June 12, 2018 at 5.00 p.m. New York City time / 11.00 p.m. CEST time.

Please see below for more information on the tender offers.

For more information, please contact

Ablynx
Dr Edwin Moses
CEO
t:   [phone]
m: [phone]
e:  [e-mail]

Lies Vanneste
Director Investor Relations
t:   [phone]
m: [phone]
e:  [e-mail]

Ablynx media relations:
Consilium Strategic Communications
Mary-Jane Elliott, Philippa Gardner, Sukaina Virji