ABLYNX INITIATES A SINGLE AND MULTIPLE DOSE PHASE I STUDY OF CAPLACIZUMAB IN HEALTHY JAPANESE SUBJECTS

• To assess the safety and tolerability of single and multiple doses of caplacizumab in Japanese healthy volunteers
• To compare the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of caplacizumab in Japanese and Caucasian subjects

To evaluate the immunogenicity of caplacizumab in Japanese subjects

GHENT, Belgium, 26 June 2017 - Ablynx [Euronext Brussels: ABLX; OTC: ABYLY] today announced that the first Japanese healthy volunteers have been dosed in the Phase I single centre, randomised, double-blind, placebo-controlled study of caplacizumab, its first-in-class anti-von Willebrand factor (vWF) Nanobody® being developed for the treatment of acquired thrombotic thrombocytopenic purpura (aTTP).

The goal of this Phase I study is to assess the safety, tolerability, PK and PD profiles and immunogenicity of caplacizumab in healthy Japanese subjects, before initiating studies in Japanese patients with aTTP. The study consists of single ascending dose and multiple dose parts with blinded safety reviews prior to proceeding to a higher dose or multiple dosing (NCT03172208). In total, 60 healthy Japanese and Caucasian subjects will be enrolled into the trial.

Dr Robert K. Zeldin, Chief Medical Officer at Ablynx, commented:

"The start of this Phase I study is an important step in making caplacizumab available to Japanese patients suffering from aTTP. The study results are expected to provide insights on the safety and dosing of caplacizumab in Japanese subjects and enable bridging of data between Japanese and Caucasian populations. We are looking forward to reporting the results of this study before the end of 2017. This year, we will also report the top line results from our Phase III HERCULES study in 145 patients with acquired TTP."

About caplacizumab

Caplacizumab is a bivalent anti-vWF Nanobody that received Orphan Drug Designation in Europe and the United States in 2009. Caplacizumab blocks the interaction of ultra-large vWF multimers (ULvWF) with platelets and, therefore, has an immediate effect on platelet aggregation and the ensuing formation and accumulation of the microclots that cause the severe thrombocytopenia, tissue ischemia and organ dysfunction in aTTP. This immediate effect of caplacizumab has the potential to protect  the patient from the manifestations of the disease while the underlying disease process resolves.