GHENT, BELGIUM--(Marketwire - November 10, 2011) -

* ALX-0081 has an acceptable safety profile * ALX-0081 performed well against the GPIIb/IIIa inhibitor ReoPro(®)

GHENT, Belgium, 10 November 2011 - Ablynx [Euronext Brussels: ABLX] today announced head-line data from a proof-of-concept (POC) Phase II study with the anti-vWF Nanobody, ALX-0081, in high risk patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

In this multi-national, multi-institutional, open-label Phase II study, Ablynx enrolled a total of 380 high risk ACS patients undergoing PCI. These patients were randomized to receive either ALX-0081 or the GPIIb/IIIa inhibitor ReoPro(Ò).( )In addition, all patients received the standard anti- thrombotic regimen of aspirin, heparin and Plavix(®).

The primary endpoint of the study was a composite of all bleeding events according to the TIMI (thrombolysis in myocardial infarction) classification and it was assessed for all patients within 30 days of study drug administration. The bleeding events were judged by a blinded central endpoint review committee comprised of haematology, cardiology and clinical pharmacology experts. The primary endpoint was designed to show a 40% reduction in bleeding events with ALX-0081 compared with ReoPro(®). This goal was not achieved as there was no statistically significant difference between the total number of bleeding events for the two compounds. Both ALX-0081 and ReoPro(®) showed comparable bleeding profiles as outlined below:

* 36 (19.9%) patients reported bleeding events (insignificant, minor and major bleeds) in the ALX-0081 treatment group (n=181) and 28 (15.3%) patients reported bleeding events (insignificant, minor and major bleeds) in the ReoPro(®) treatment group (n=183). * Only three ALX-0081 treated patients (1.7%) and two ReoPro(®) treated patients (1.1%) showed a major bleeding event during the 30 day period following the PCI procedure.

Clinical investigator Dr. William Wijns, Chairman of EuroPCR and first author of the current ESC Practice Guidelines on Myocardial Revascularisation, commented on the study results: "We are very pleased with the safety profile of this novel anti-vWF Nanobody as it shows a low event rate for all bleeding events and importantly did not significantly increase the rate of major bleeding events compared to ReoPro(Ò). In this study, the overall rate of bleeding in the ReoPro(Ò) plus anti-thrombotic therapy arm at current recommended doses was much lower than was originally anticipated from historical clinical studies, where bleeding rates reached 41% for ReoPro(Ò). This could be related to improvements in optimization of the standard anti-thrombotic regimen that are frequently required in patients taking ReoPro(Ò). Such optimization was not required in the ALX-0081 arm so we may be seeing some positive bias toward the optimised ReoPro(Ò) regimen. Looking back to the bleeding events reported in the FDA review of the EPILOG study results at time of the BLA for ReoPro(Ò), then today's ALX-0081's bleeding profile is promising and provides potential directions of investigation for further improvement of treatment schedules and concomitant anti-thrombotic therapies"

Josi Holz, Chief Medical Officer of Ablynx, commented. "We set a very high bar for this POC study in order to determine quickly whether ALX- 0081 had significant commercial potential in the anti-thrombotic therapy field. The current results are encouraging scientifically, but, as we have guided previously, since there is no statistical difference between the safety profile of ALX-0081 and ReoPro(Ò), and with the increasing, and intense commercial competition in this area, we will not pursue the ACS indication further at this time. Instead we will focus our attention and activities with anti-vWF Nanobodies on the orphan disease indication TTP where we are currently conducting a Phase II study in patients with acquired TTP. The Phase II ACS data will, however, provide us with very useful safety information to support the potential filing for our anti-vWF Nanobodies in the treatment of patients with acquired TTP."

Complete version of the press release: http://hugin.info/137912/R/1562875/484367.pdf

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Source: Ablynx via Thomson Reuters ONE

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