GHENT, Belgium, 20 February 2013 - Ablynx [Euronext Brussels: ABLX], a biopharmaceutical company engaged in the discovery and development of Nanobodies®, a novel class of therapeutic proteins based on single-domain antibody fragments for a range of serious human diseases, today announced its promotion to the Belgian Mid-Cap Index (Bel Mid Index or BELMID). Ablynx will be included in the BELMID Index as of the 18^th of March 2013.

The entry of Ablynx to the BELMID Index is a result of performance of the Ablynx shares and is based on Ablynx's market capitalisation, free float and liquidity in the period up to end of January 2013.

About Ablynx

Ablynx is a biopharmaceutical company engaged in the discovery and development of Nanobodies^®, a novel class of therapeutic proteins based on single-domain antibody fragments, for a range of serious human diseases, including inflammation, haematology, oncology and pulmonary disease. Today, the Company has approximately 25 programmes in the pipeline and five Nanobodies at clinical development stage. Ablynx has ongoing research collaborations and significant partnerships with major pharmaceutical companies including Boehringer Ingelheim, Merck Serono, Novartis and Merck & Co. The Company is headquartered in Ghent, Belgium. More information can be found on www.ablynx.com.

For more information, please contact

Ablynx:
Dr Edwin Moses
Chairman and CEO
t:   +32 (0)9 262 00 07
m: +44 (0)7771 954 193 /
     +32 (0)473 39 50 68
e:  edwin.moses@ablynx.com

Marieke Vermeersch
Associate Director Investor Relations
t:   +32 (0)9 262 00 82
m: +32 (0)479 49 06 03
e:  marieke.vermeersch@ablynx.com
Follow us on Twitter @AblynxABLX

M:Communications:
Mary-Jane Elliott, Amber Bielecka, Claire Dickinson
t:   +44 207 920 2330
e:  ablynx@mcomgroup.com