ABLYNX ANNOUNCES RESULTS FOR THE FIRST NINE MONTHS OF 2017 AND A YEAR-TO-DATE BUSINESS UPDATE

REGULATED INFORMATION

Positive Phase III results with caplacizumab and a successful U.S. IPO

GHENT, Belgium, 16 November 2017 - Ablynx NV [Euronext Brussels and Nasdaq: ABLX] today announced its non-audited financial results for the first nine months of 2017, a business update for the year-to-date and the outlook for the next period.

Business highlights for the year-to-date

• Corporate
  • In October, successfully raised $230 million (approximately €195 million) as part of an initial U.S. public offering on Nasdaq
  • In October, established a U.S. subsidiary, Ablynx Inc., and appointed a General Manager based in the U.S.A. to lead the commercialisation of caplacizumab
• Caplacizumab - wholly-owned anti-vWF Nanobody® for the treatment of acquired thrombotic thrombocytopenic purpura (aTTP)
  • In February, submitted a marketing authorisation application (MAA) to the European Medicines Agency (EMA)
  • In July, received Fast Track designation from the U.S. Food and Drug Administration (FDA)
  • In October, reported positive topline results from the Phase III HERCULES study, meeting primary and key secondary endpoints
  • In October, completed recruitment of eligible HERCULES patients into the three-year follow-up study (85% roll-over rate)
• ALX-0171 - wholly-owned inhaled anti-RSV Nanobody for the treatment of RSV infections
  • In August, completed the sequential dose escalation part of the Phase IIb RESPIRE study in 36 infants and, after receiving approval from the Data Monitoring Committee, subsequently initiated the parallel dose part in 144 infants, with topline results expected in H2 2018
• Vobarilizumab - anti-IL-6R Nanobody for the treatment of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE)
  • Advanced the Phase II STEADY study in 312 patients recruited with SLE, with topline results expected in H1 2018
  • Continued the open-label extension study in RA for those patients who had completed the Phase IIb studies (94% roll-over rate), with topline results expected in H2 2018
• Partnered programmes
  • In May, received a €15 million milestone payment from Merck KGaA for the completion of a pre-clinical package for ALX-1141 targeting ADAMTS-5 in osteoarthritis, with Merck KGaA subsequently starting a Phase I study
  • In June, received a €2.5 million milestone payment from Merck & Co., Inc. as a result of their initiation of a toxicology study with a bi-specific Nanobody as part of our immuno-oncology collaboration
  • In July, entered into a new research collaboration with Sanofi on up to eight new programmes, focused initially on immune-mediated inflammatory diseases, with €23 million in upfront payments and up to €2.4 billion in potential milestones plus tiered royalties

Financial highlights for the first nine months of 2017