ALX-0081, found to be safe, well tolerated and a potent inhibitor of platelet aggregation

Ablynx has unveiled results from the open label extension of the phase Ib study of its anti-thrombotic, ALX-0081, in patients with stable angina undergoing percutaneous coronary intervention (PCI).

The results supported those of the original phase I study with ALX-0081 and collectively provided proof-of-concept that ALX-0081 is safe and well tolerated and a potent inhibitor of platelet aggregation.

The study was designed to investigate the effect of ALX-0081, which inhibits von Willebrand Factor (vWF), on vWF-mediated clotting, measured using platelet aggregation biomarkers. Additional objectives of the study were to gather data regarding safety and administration.

The study involved a total of 22 patients with stable angina undergoing elective PCI. All patients received standard anti-thrombotic therapy, including aspirin, heparin and plavix, in addition to ALX-0081 (20 patients) or placebo (2 patients).

All 22 patients received four bolus injections of ALX-0081 or placebo every six hours over 24 hours. vWF-mediated platelet aggregation was measured via the biomarker RICO (ristocetin cofactor). All 20 patients who received ALX-0081 experienced complete RICO inhibition, that was statistically significant compared to placebo.

ALX-0081 was safe and well tolerated and did not result in clinically relevant bleeding events. No evidence of anti-drug antibodies was detected up to 30 days after the last injection, said the company.

Professor Jozef Bartunek, primary investigator of the phase Ib study, said: “With the highly statistically significant inhibition of vWF, we have achieved proof-of-concept with the biomarker indicating ALX-0081 is a potent inhibitor of vWF-mediated clotting in patients with stable angina undergoing PCI.”

Edwin Moses, CEO and chairman of Ablynx, said: “We are delighted to see further evidence of efficacy and safety for ALX-0081 in patients with cardiovascular disease. This is a novel target and ALX-0081 could become an important next generation thrombosis treatment. Ablynx recently initiated a Phase II study with ALX-0081 and we look forward to obtaining data from this study by the end of 2010.”