ABLYNX ANNOUNCES HALF-YEAR RESULTS FOR 2008 ABLYNX INITIATES THE FIRST OF TWO PHASE IIb RA STUDIES WITH ITS ANTI-IL-6R NANOBODY, PARTNERED WITH ABBVIE Phase IIb study to evaluate ALX-0061, in combination with methotrexate, in adult patients with moderate to severe rheumatoid arthritis (RA) GHENT, Belgium, 17 March 2015 - Ablynx [Euronext Brussels: ABLX; OTC: ABYLY] today announced that it has administered the first dose in the Phase IIb study to evaluate the efficacy and safety of its anti-IL-6R Nanobody®, ALX-0061, administered subcutaneously in combination with methotrexate (MTX) in adult patients with active RA, despite MTX therapy. The study aims to identify the optimum dose and frequency of administration of ALX-

0061 for the next phases of development.
In September 2013, Ablynx and AbbVie entered into a global license agreement, worth up to US$840 million plus double-digit royalties, to develop and commercialise ALX-0061. As part of the agreement, Ablynx is responsible for Phase II clinical development of ALX-0061 in both RA and systemic lupus erythematosus (SLE).
The current Phase IIb study is a multi-centre, randomised, double-blind, placebo-controlled dose-range finding study of ALX-0061, administered subcutaneously in combination with MTX (a commonly used first-line DMARD1 agent for patients with RA), in subjects with moderate to severe RA, despite MTX therapy. The study is expected to enrol 330 subjects in the United States, Europe and South America, who will be randomly assigned to placebo or four different dose groups of ALX-0061 administered subcutaneously. Administration will be performed every
2 weeks or every 4 weeks. Subjects will be followed for efficacy up to and including week 24 and for safety up to and including week 34. Following completion of the 24-week study, eligible subjects will be invited to participate in an open-label extension study.
The primary endpoint is the ACR20 response2 at week 12, a broadly accepted clinical response measure to demonstrate reduction in RA signs and symptoms. The secondary endpoints include higher level of response assessments, documentation of efficacy of ALX-0061 over time, as well as of the effects of ALX-0061 on the improvement in physical function and health-related quality of life. Other planned assessments include the determination of ALX-0061 levels, biomarkers, safety, tolerability and immunogenicity.

Dr Edwin Moses, CEO of Ablynx, commented:

"Ablynx and our partner AbbVie are committed to making ALX-0061 available for people living with rheumatoid arthritis. The start of this first Phase IIb study in this chronic and progressive disease is therefore an important milestone. The programme is progressing according to plan and we expect top line results from the study before the end of 2016. If the results meet pre-defined success criteria, AbbVie will exercise its right to in-license ALX-
0061 and be responsible for subsequent Phase III clinical development and commercialisation."

About ALX-0061

ALX-0061 targets the interleukin 6 pathway via its IL-6 receptor (IL-6R) and has been developed for the treatment of RA and possibly systemic lupus erythematosus (SLE). IL-6 is a pro-inflammatory cytokine that plays a role in T-cell activation, production of acute phase proteins in response to inflammation, induction of immunoglobulin production, and stimulation of osteoclast differentiation and activation. ALX-0061 (26kD) has a very strong affinity for the soluble IL-6R and contains an anti-IL-6R Nanobody linked to an anti-human serum

1 DMARD: disease modifying anti-rheumatic drug

2 ACR (American College of Rheumatology) responses measure improvements in tender and swollen joint counts and improvements in three of five other

disease-activity measures. To achieve an ACR20 the patients must show an improvement of at least 20%.

albumin (HSA) Nanobody, thereby increasing the in vivo serum half-life. Phase I/II proof-of-concept results with ALX-0061 were published in February 2013, followed by the signing of a global exclusive licensing deal with AbbVie in September 2013for the development and commercialisation of ALX-0061.

About RA and SLE

RA is characterised by chronic and progressive joint inflammation that typically results in permanent, debilitating tissue damage, which is further compounded by joint deformation. The condition is associated with lower quality of life, premature death, disability, and unemployment. It is estimated that up to 1 percent of the adult population worldwide suffer from RA.
SLE is a complex, multi-organ, autoimmune disorder characterised by the production of pathogenic autoantibodies and tissue deposition of immune complexes, which result in widespread tissue damage. Although the aetiology of SLE is not fully understood, multiple genetic, environmental, and hormonal factors have been implicated in its development. The disease displays a broad variety of symptoms and highly variable clinical features, including systemic, cutaneous, renal, musculoskeletal, and haematological manifestations. Approximately 5 million people worldwide suffer from a form of lupus and 90 percent of people diagnosed are women.

About Ablynx

Ablynxis 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 30 proprietary and partneredprogrammesin development in various therapeutic areas including inflammation, haematology, oncology and respiratory disease. The Company has collaborations with multiple pharmaceutical companies including AbbVie, Boehringer Ingelheim, Merck & Co., Inc, Merck Serono and Novartis. 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
CEO
t: +32 (0)9 262 00 07
m: +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
@AblynxABLX

Ablynx media relations Consilium Strategic Communications: Mary-Jane Elliott, Jonathan Birt, Amber Bielecka, Lindsey Neville t: +44 203 709 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 expr essed 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 s uch 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 t he 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.

distributed by