Ablynx : 30/08/2017 PUBLICATION IN ACCORDANCE WITH ARTICLE 14 OF THE BELGIAN LAW OF 2 MAY 2007 REGARDING THE PUBLICATION OF MAJOR SHAREHOLDINGS (THE "TRANSPARENCY LAW")

REGULATED INFORMATION

FMR LLC (taking into account the holdings of its subsidiary undertakings) currently holds a total of 5,813,507 Ablynx shares, representing 9.50% of the current 61,169,732 outstanding Ablynx shares, increased from 9.19% previously.

FMR LLC has notified Ablynx that the shareholding in Ablynx held by FMR Co., Inc., a subsidiary of Fidelity Management & Research Company, which itself is a subsidiary of FMR LLC (the ultimate parent company), has exceeded the 5% threshold as of 23 August 2017.

According to the notification, FMR Co., Inc.'s holding of Ablynx shares and voting rights has increased to 3,209,899 shares, corresponding to 5.25% of the current 61,169,732 outstanding Ablynx shares (versus 3.61% in previous notification dated 13 June 2017).

The notified details are presented below:

* The holdings attributable to FMR LLC arise from holdings of various undertakings for collective investment that are managed by FMR Co., Inc., Fidelity Institutional Asset Management Trust Company and FIAM LLC, each of which are entities that are subsidiaries of, and controlled by, FMR LLC. These undertakings for collective investment have granted FMR LLC discretionary power to vote the securities in accordance with the FMR LLC board proxy voting policy. FMR LLC is not a controlled undertaking.

** Type of financial instrument: "Right of Recall"

Full versions of all transparency notifications are available on Ablynx website, under the section Investors.

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.

@AblynxABLX

Mary-Jane Elliott, Philippa Gardner, Sukaina Virji t: +44 (0)20 3709 5700

e: ablynx@consilium-comms.com

Certain statements, beliefs and opinions in this press release are forward-looking, which reflect the Company or, as appropriate, the Company directors' current expectations and projections about future events. By their nature, forward-looking statements involve a number of risks, uncertainties and assumptions that could cause actual results or events to differ materially from those expressed or implied by the forward-looking statements. These risks, uncertainties and assumptions could adversely affect the outcome and financial effects of the plans and events described herein. A multitude of factors including, but not limited to, changes in demand, competition and technology, can cause actual events, performance or results to differ significantly from any anticipated development. Forward looking statements contained in this press release regarding past trends or activities should not be taken as a representation that such trends or activities will continue in the future. As a result, the Company expressly disclaims any obligation or undertaking to release any update or revisions to any forward-looking statements in this press release as a result of any change in expectations or any change in events, conditions, assumptions or circumstances on which these forward-looking statements are based. Neither the Company nor its advisers or representatives nor any of its parent or subsidiary undertakings or any such person's officers or employees guarantees that the assumptions underlying such forward-looking statements are free from errors nor does either accept any responsibility for the future accuracy of the forward-looking statements contained in this press release or the actual occurrence of the forecasted developments. You should not place undue reliance on forward-looking statements, which speak only as of the date of this press release.