GHENT, Belgium, Sept. 29, 2016 (GLOBE NEWSWIRE) -- Ablynx [Euronext Brussels: ABLX; OTC: ABYLY] announced that it will today present additional data from post-hoc analyses of the Phase II TITAN study of its wholly-owned Nanobody®, caplacizumab, in patients with acquired thrombotic thrombocytopenic purpura (aTTP), at the first European Congress on Thrombosis and Haemostasis (ECTH), being held from 28-30 September 2016 in The Hague, The Netherlands. Shortly after the conference, the presentation will be available on the Ablynx website under the R&D portfolio section.
Acquired TTP is an acute, ultra-rare, life-threatening blood clotting disorder in which uncontrolled platelet aggregation and microclot formation cause small blood vessel occlusions throughout the body, resulting in thrombotic complications and widespread organ damage. Despite the current standard-of-care treatment of daily plasma exchange (PEX) and immunosuppression, episodes of aTTP are still associated with a mortality rate of up to 20%, with most deaths occurring within 30 days of diagnosis. Furthermore, patients are at risk of acute thromboembolic complications (e.g. stroke, venous thrombosis and myocardial infarction) and of recurrence of disease. In addition, some patients are refractory to therapy, which is associated with a very poor prognosis for survival of an acute episode of aTTP. Data from the French Reference Center for Thrombotic Microangiopathies showed that 50% of patients who died from an acute episode were refractory to treatment.
Post-hoc analyses of the Phase II TITAN study data were performed to assess the impact of caplacizumab on a composite endpoint of major thromboembolic complications and aTTP-related mortality, as well as on refractoriness to standard treatment. The results demonstrate that a clinically meaningful lower proportion of subjects treated with caplacizumab experienced one or more major thromboembolic events, or died, as compared to placebo (11.4% versus 43.2%). In addition, fewer caplacizumab-treated patients, compared to those who received placebo, were refractory to treatment (5.7% versus 21.6%; and 0% versus 10.8%, respectively depending on the definition of refractoriness4). There were two deaths in the placebo group and both those patients were refractory to treatment; no deaths were reported in the caplacizumab group.
A Phase III confirmatory study of caplacizumab is currently ongoing which includes prospectively defined assessments of these clinically relevant endpoints.
Professor Flora Peyvandi, Principal Investigator for the TITAN study at IRCCS Maggiore Hospital Foundation, University of Milan, Italy, commented: "Acquired TTP is a very severe disease with high unmet medical need. Any new treatment option would need to act fast to immediately inhibit the formation of micro-clots in order to protect the patient during the acute phase of the disease and so have the potential to avoid the resulting complications. The topline results and the subsequent post-hoc analyses of the Phase II TITAN data demonstrate that caplacizumab has the potential to reduce the major morbidity and mortality associated with acquired TTP, and confirm our conviction that it should become an important pillar in the management of acquired TTP."
Caplacizumab is a highly potent and selective bivalent anti-von Willebrand Factor (vWF) Nanobody that received Orphan Drug Designation in the United States and Europe 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 and organ and tissue damage in aTTP. This immediate effect protects the patient from the manifestations of the disease while the underlying disease process resolves.
The efficacy and safety of caplacizumab in conjunction with the standard of care (PEX) were evaluated in the Phase II TITAN study in 75 patients with aTTP. Caplacizumab was well-tolerated and the primary endpoint of reduction in time to platelet normalisation was met (p=0.005). Treatment with caplacizumab resulted in a nearly 40% reduction in time to platelet count normalisation as compared to placebo (i.e., a faster reversion of thrombocytopenia with consequent reduced use of PEX). Moreover, during treatment, caplacizumab reduced aTTP recurrences by 71% compared to placebo when administered as an adjunct to standard of care.
These Phase II results will serve as the basis for filing for conditional approval of caplacizumab in Europe in early 2017. The confirmatory Phase III HERCULES study is currently ongoing and will support the BLA filing in the United States. Results from this Phase III study are expected by the end of 2017.
Caplacizumab has the potential to be the first therapeutic specifically approved for the treatment of acquired TTP.
aTTP is an acute, ultra-rare, life-threatening, blood clotting disorder, affecting up to 11 per million people worldwide. It has a sudden onset caused by impaired activity of the ADAMTS13 enzyme (typically <10% of that in normal plasma), leaving ULvWF molecules uncleaved (vWF is an important protein involved in the blood clotting process). These ULvWF molecules spontaneously bind to blood platelets, resulting in severe thrombocytopenia (very low platelet count) and micro-clot formation in small blood vessels throughout the body, leading to thrombotic complications and widespread organ damage.
Up to 20% of patients die from an initial aTTP episode with most deaths occurring within 30 days of diagnosis. In addition to the acute risks of the disease, patients experiencing an episode of aTTP may suffer long-term consequences such as cognitive deficits, depression, and arterial hypertension, and are at risk for recurrence. The recurrence rate ranges from 10-84% and typically occur within 1-2 years, but recurrences have been reported up to 30 years after the initial episode.
Ablynx is a biopharmaceutical company engaged in the development of Nanobodies®, proprietary therapeutic proteins based on single-domain antibody fragments, which combine the advantages of conventional antibody drugs with some of the features of small-molecule drugs. Ablynx is dedicated to creating new medicines which will make a real difference to society. Today, the Company has more than 45 proprietary and partnered programmes in development in various therapeutic areas including inflammation, haematology, immuno-oncology, oncology and respiratory disease. The Company has collaborations with multiple pharmaceutical companies including AbbVie, Boehringer Ingelheim, Eddingpharm, Genzyme, Merck & Co., Inc., Merck KGaA, Novartis, Novo Nordisk and Taisho Pharmaceuticals. The Company is headquartered in Ghent, Belgium. More information can be found on www.ablynx.com.
For more information, please contact
Dr Edwin Moses
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Director IR & Corporate Communications
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Ablynx media/analyst relations
Julia Phillips, Brett Pollard, Mo Noonan, Matthew Moss
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 Veyradier, NEJM 2016: "von Willebrand Factor - A new target for TTP treatment?"
 Scully et al, Br J Hem 2012; Sarode et al, J Clin Apher 2014; Chaturvedi et al, Am J Hem 2013
 Benhamou, Y.et al., Haematologica 2012
 Defined as: 'failure of platelet response after 7 days despite daily plasma exchange treatment' or 'absence of platelet count doubling after 4 days of standard treatment, and LDH>upper limit of normal
 Benhamou, Y. et al, Journal of thrombosis and haemostasis 2015
 Peyvandi et al, notes to editor NEJM 2016
 Deford et al, Blood 2013
 Thejeel et al, American journal of hematology 2016
 Kremer Hovinga et al, Blood 2010
 Falter et al, Hamostaseologie 2013
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