ABLYNX'S ANTI-vWF NANOBODY, CAPLACIZUMAB, ACHIEVES CLINICAL PROOF-OF-CONCEPT IN PHASE II TITAN STUDY

• First-in-class potential with orphan drug status for the treatment of acquired thrombotic thrombocytopenic purpura
• Proof-of-concept with statistically significant 39% decrease in time to normalisation of platelet count compared to placebo for patients who received no plasma exchange prior to initial treatment with caplacizumab

The group of patients treated with caplacizumab in conjunction with the standard of care achieved confirmed platelet normalisation at more than twice the rate of the group receiving the standard of care plus placebo during the 30-day period after the start of study drug. The p-value was 0.013

81% of patients achieved complete remission compared to 46% in the placebo arm

73% less exacerbations compared to placebo during treatment with caplacizumab

Generally well-tolerated, with manageable increase in bleeding tendency

Results will be discussed during a webcast presentation today at 17h CET, 11 am EST
The webcast may be accessed on the home page of the Ablynx website at www.ablynx.com
or by clicking here
To participate in the Q&A, dial [phone] with confirmation code 5793077.

GHENT, Belgium, 17 June 2014 - Ablynx [Euronext Brussels: ABLX] today announced that it has achieved positive results in the Phase II TITAN study with the anti-vWF Nanobody®, caplacizumab, in patients with acquired thrombotic thrombocytopenic purpura (TTP), a rare disorder of the blood coagulation system that causes microthrombi to form which can block small blood vessels throughout the body. Treatment with caplacizumab plus standard of care resulted in a statistically significant reduction in time to confirmed normalisation and was associated with fewer exacerbations and more complete remissions as compared to patients receiving the standard of care plus placebo.

The worldwide Phase II TITAN clinical trial was a single-blinded, randomised, placebo-controlled study which recruited from January 2011 to January 2014. In total, 75 patients were randomized on a 1:1 basis with one active drug treatment arm and one placebo arm. All patients received the current standard of care which is primarily multiple plasma exchanges. The protocol for the study was adapted in September 2013, to also allow one day of plasma exchange prior to study enrolment. Those patients in the active drug treatment arm immediately received an intravenous bolus dose of 10 mg caplacizumab and then a 10 mg subcutaneous dose of the drug daily until 30 days had elapsed after the final plasma exchange. Patients in the control arm received placebo at the same time points.