ABLYNX PRICES $200 MILLION INITIAL PUBLIC OFFERING IN THE UNITED STATES

REGULATED INFORMATION - INSIDE INFORMATION
25 October 2017 - 2 am CEST

GHENT, Belgium, 25 October 2017 - Ablynx NV [Euronext Brussels: ABLX; OTC: ABYLY], a late-stage clinical biopharmaceutical company utilising its proprietary Nanobody® platform to develop treatments for a broad range of therapeutic indications with an unmet medical need, announced today the pricing of its initial U.S. public offering totaling $200 million gross proceeds from the sale of 11,430,000 ordinary shares in the form of American Depositary Shares ("ADSs") at a price of $17.50 per ADS, before underwriting discounts.

Ablynx has granted the underwriters during the 30-day stabilization period an option to purchase up to an additional 1,714,500 ordinary shares in the form of ADSs in connection with the offering, representing up to 15% of the total number of ADSs placed in the offering. This option can be exercised during the 30-day period commencing 24 October 2017.

The closing of the offering is expected to occur on 27 October 2017, subject to customary closing conditions.

Each of the ADSs offered represents the right to receive one ordinary share.

Ablynx's ordinary shares are currently listed on Euronext Brussels under the symbol "ABLX". The ADSs are expected to begin trading on the NASDAQ Global Select Market on 25 October 2017 under the symbol "ABLX."

BofA Merrill Lynch, J.P. Morgan and Jefferies are acting as joint book-running managers for the offering. Baird, Bryan, Garnier & Co. and Ladenburg Thalmann are acting as co-managers for the offering. J.P. Morgan is acting as stabilization agent on behalf of the underwriters.

A registration statement relating to and describing the terms of the offering was declared effective by the U.S. Securities and Exchange Commission on 24 October 2017.

The securities to be issued in the offering are being offered only by means of a prospectus. When available, copies of the final prospectus can be obtained from BofA Merrill Lynch at NC1-004-03-43, 200 North College Street, 3rd floor, Charlotte North Carolina 28255-0001, Attn: Prospectus Department, or by email at [e-mail]; from J.P. Morgan at Attn: Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, or by telephone at [phone]; or from Jefferies at 520 Madison Avenue, 2nd Floor, New York, New York 10022, Attn: Equity Syndicate Prospectus Department, or by email at [e-mail].