LEUVEN, Belgium and LUND, Sweden, February 23 /PRNewswire/ --

- Trial to Assess the Benefits of Partial Factor VIII Inhibition in Patients Undergoing Knee Replacement Surgery

ThromboGenics NV (Euronext Brussels: THR) and co-development partner BioInvent International (OMXS: BINV) announce today that the first patient has been enrolled in the Phase II trial with their long-acting anticoagulant TB-402 for the prophylaxis of Deep Vein Thrombosis (DVT) following orthopaedic surgery. TB-402, which is given as a single injection post surgery, could overcome the major drawbacks such as bleeding and the need for extensive patient monitoring associated with current anti-coagulant therapy.

TB-402 is a recombinant human monoclonal antibody that targets Factor VIII, a key component of the coagulation cascade. TB-402 is a novel anticoagulant agent, which may deliver important clinical benefits due to it only partially inhibiting Factor VIII activity even when given in very high doses. This novel mode of action is expected to reduce the risk of undesirable bleeding events and the need for patient monitoring, the two main drawbacks associated with current anticoagulants. In addition, TB-402 is a long-acting agent which means that patients are expected to receive just one single dose after surgery to prevent the development of DVT, as opposed to all current treatment options which require daily treatment for up to several weeks.

The Phase II trial is an active (enoxaparin)-controlled, dose-escalating, multicenter, prospective, randomised, open label trial evaluating TB-402 for the prophylaxis of DVT after knee surgery. The study will assess three different doses of TB-402 given as a single intravenous bolus injection post knee replacement surgery. The trial will enrol 300 patients across 36 centers mainly in Central Europe. The primary endpoint is the safety and efficacy of the three escalating doses of TB-402. It is anticipated that the study will conclude by the end of 2010.

Patrik De Haes, CEO of ThromboGenics, commented on today's news We are very excited about the start of the Phase II trial for TB-402. Our work to date suggests that this novel agent could represent a major advance in anti-coagulant therapy, given our expectation that it will cause fewer unwanted bleeding events and will require no monitoring of patients. This combined with its ability to be used as a one-off treatment could make TB-402 the anti-coagulant of choice to prevent DVT in patients undergoing surgery. Given the size of the market opportunity for TB-402 and the sales reach that will be needed to engage with the potential prescribers of TB-402, it is our intention to seek a partner to undertake the later stage development and commercialisation of this exciting new agent.

Svein Mathisen, CEO of BioInvent, also commented, The initiation of this Phase II trial is another successful step forward in the clinical development of our antibody product development portfolio. TB-402 addresses a broad market and has potentially significant advantages over existing anti-coagulants. We are hopeful it will have application in a number of clinical settings.

About Deep Vein Thrombosis (DVT)

DVT is caused when a blood clot forms in a deep vein, most commonly in the deep veins of the lower leg. DVT is a major public health issue and it is estimated that in the U.S. alone, more than 350,000 individuals are affected by DVT or pulmonary embolism (PE) each year. Moreover, DVT and PE together may be responsible for more than 100,000 deaths in the U.S. each year.(1)

It is estimated that by 2015, 1.4 million patients will undergo knee replacement and 600,000 patients will undergo hip replacement in the U.S. if current trends persist.(2) Patients undergoing hip replacement or knee surgery are particularly at risk of developing DVT and all patients are therefore treated with anticoagulants prophylactically in order to reduce the risks of blood clots. The annual sales of anticoagulants worldwide are over $5 billion. Nevertheless, available anticoagulants are still inconvenient and associated with an increased risk of bleeding. Improved anticoagulants are therefore required. In particular, agents that allow for improved ease of administration (without requirement for daily dosing and frequent dose adjustment) would fill a significant unmet need.

Legal disclaimer

This press release contains statements about the future, consisting of subjective assumptions and forecasts for future scenarios. Predictions for the future only apply as of the date they are made and are, by their very nature, in the same way as research and development work in the biotech segment, associated with risk and uncertainty. With this in mind, the actual outcome may deviate significantly from the scenarios described in this press release.

Notes to Editors:

About ThromboGenics

ThromboGenics is a biotechnology company focused on the discovery and development of biopharmaceuticals for the treatment of eye disease, vascular disease and cancer. The Company's lead product Microplasmin is in Phase III clinical development for the non-surgical treatment of back of the eye diseases. Microplasmin is also being evaluated in Phase II clinical development for additional vitreoretinal indications and as a potential therapy for stroke. ThromboGenics is also developing novel antibody therapeutics in collaboration with BioInvent International; these include TB-402 (Anti-Factor VIII), a long acting anti-coagulant, and TB-403 (anti-PlGF) for cancer.

ThromboGenics has built strong links with the University of Leuven and the Flanders Institute for Biotechnology (VIB) and has exclusive rights to certain therapeutics developed at these institutions. ThromboGenics is headquartered in Leuven, Belgium and has subsidiaries in Dublin, Ireland and New York, U.S. The Company is listed on Eurolist by Euronext Brussels under the symbol THR. More information is available at http://www.thrombogenics.com.

About BioInvent

BioInvent International AB, listed on the OMX Nordic Exchange Stockholm (BINV), is a research-based pharmaceutical company that focuses on developing antibody drugs. The Company is currently running innovative drug projects within the areas of thrombosis, cancer and atherosclerosis. The Company has signed various strategic alliances around these product candidates and is developing them in collaboration with partners including Genentech, Roche and ThromboGenics.

These projects are based around a competitive and in substance patented antibody development platform. The scope and strength of this platform is also utilised by partners, such as ALK-Abello, Bayer HealthCare, ImmunoGen, OrbusNeich, Sanofi-Aventis, UCB and XOMA. More information is available at http://www.bioinvent.com.

(1) The Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism, September 15, 2008, p.1.

(2) Changes in Surgical Loads and Economic Burden of Hip and Knee Replacements in the US: 1997-2004, Sunny Kim, Arthritis Rheumatism (Arthritis Care Research), April 15, 2008; 59:4, pp. 481-488.

ThromboGenics NV Gaston Geenslaan 1 B-3001 Leuven Belgium Tel: +32(0)16-75-13-10 http://www.thrombogenics.com BioInvent International AB (publ) Co. reg. No. 556537-7263, Address: Solvegatan 41 Mailing address: SE-223 70 LUND Tel: +46(0)46-286-85-50 info@bioinvent.com http://www.bioinvent.com For further information, please contact: ThromboGenics NV Patrik De Haes MD Chief Executive Officer Tel : +32(0)16-75-13-10 E-mail: patrik.dehaes@thrombogenics.com: Andy De Deene MD Clinical Director Europe Tel: +32(0)16-75-13-10 E-mail andy.dedeene@thrombogenics.com Citigate Dewe Rogerson Amber Bielecka, David Dible, Nina Enegren Tel: +44(0)207-638-95-71 E-mail: amber.bielecka@citigatedr.co.uk BioInvent International AB Svein Mathisen President CEO Tel: +46(0)46-286-85-67 Mobile: +46(0)708-97-82-13 E-mail: svein.mathisen@bioinvent.com Cristina Glad Executive Vice President Tel: +46(0)46-286-85-51 Mobile: +46(0)708-16-85-70 E-mail: cristina.glad@bioinvent.com College Hill (media enquiries) Holly Griffiths, Sue Charles, John McIntyre Tel: +44(0)20-7457-2020 E-mail: bioinvent@collegehill.com

ThromboGenics NV, Gaston Geenslaan 1, B-3001 Leuven, Belgium, Tel: +32(0)16-75-13-10, http://www.thrombogenics.com; BioInvent International AB (publ), Co. reg. No. 556537-7263, Address: Solvegatan 41, Mailing address: SE-223 70 LUND, Tel: +46(0)46-286-85-50, info@bioinvent.com, http://www.bioinvent.com; For further information, please contact: ThromboGenics NV, Patrik De Haes MD, Chief Executive Officer, Tel : +32(0)16-75-13-10, E-mail: patrik.dehaes@thrombogenics.com: Andy De Deene MD, Clinical Director Europe, Tel: +32(0)16-75-13-10, E-mail andy.dedeene@thrombogenics.com; Citigate Dewe Rogerson, Amber Bielecka, David Dible, Nina Enegren, Tel: +44(0)207-638-95-71, E-mail: amber.bielecka@citigatedr.co.uk; BioInvent International AB, Svein Mathisen, President CEO, Tel: +46(0)46-286-85-67, Mobile: +46(0)708-97-82-13, E-mail: svein.mathisen@bioinvent.com; Cristina Glad, Executive Vice President, Tel: +46(0)46-286-85-51, Mobile: +46(0)708-16-85-70, E-mail: cristina.glad@bioinvent.com; College Hill (media enquiries), Holly Griffiths, Sue Charles, John McIntyre, Tel: +44(0)20-7457-2020, E-mail: bioinvent@collegehill.com