REGULATED INFORMATION

GHENT, Belgium, 16 January 2018 - Ablynx [Euronext Brussels and Nasdaq: ABLX] today announced, in accordance with Article 14 of the Belgian Law of 2 May 2007 regarding the publication of major shareholdings in issuers whose securities are admitted to trading on a regulated market (the "Transparency Law"), that it received a notification of shareholdings from Van Herk Investments B.V. on 15 January 2018.

Van Herk Investments B.V. notified Ablynx that it has crossed the 10% threshold on 12 January 2018 and now holds 7,629,229 voting securites of Ablynx, representing 10.21% of the current 74,720,644 outstanding voting rights of Ablynx (versus 9.99% notified previously on 11 October 2017).

The notification contains the following information:

• Reason for the notification: acquisition or disposal of voting securities or voting rights

• Notification by: a parent undertaking or a controlling person

• Persons subject to the notification requirement: Mr. A. van Herk, Van Herk Investments B.V.

• Transaction date: 12 January 2018

• Threshold that is crossed: 10%

• Denominator: 74,720,644

• Details of the notification: Van Herk Investments B.V. holds 7,629,229 voting securities of Ablynx

• Chain of controlled undertakings through which the holding is effectively being held: Van Herk Investments B.V. is controlled by Mr. A. van Herk in accordance with Articles 5 and 7 of the Dutch Companies Code.

A full version of the transparency notification is available on Ablynx website, under the section Investors.

The articles of the association of Ablynx NV provide for shareholders notification threshold of 3%, 5% or a multiple of 5% of the total number of existing voting rights.

About Ablynx

Ablynx is a biopharmaceutical company engaged in the development of Nanobodies, proprietary therapeutic proteins based on single-domain antibody fragments, which combine the advantages of conventional antibody drugs with some of the features of small-molecule drugs. Ablynx is dedicated to creating new medicines which will make a real difference to society. Today, the Company has more than 45 proprietary and partnered programmes in development in various therapeutic areas including inflammation, haematology, immuno-oncology, oncology and respiratory disease. The Company has collaborations with multiple pharmaceutical companies including AbbVie; Boehringer Ingelheim; Eddingpharm; Merck & Co., Inc., Kenilworth, New Jersey, USA; Merck KGaA; Novartis; Novo Nordisk; Sanofi and Taisho Pharmaceuticals. The Company is headquartered in Ghent, Belgium. More information can be found on www.ablynx.com.