ThromboGenics Presents Results of the Phase I Trial of TB-402 at the Prestigious American Society of Hematology Annual Meeting

LEUVEN, Belgium, December 11 /PRNewswire-FirstCall/ --

- TB-402 Shows Clear Promise as a Stable Long-acting Anticoagulant for the Prevention of Thromboembolic Disorders.

ThromboGenics NV (Euronext Brussels:THR), a biotechnology company focused on vascular and eye disease, announced that the results of the first Phase I trial of TB-402 were presented yesterday at the prestigious American Society of Hematology (ASH) 49th Annual Meeting in Atlanta, Georgia, USA. TB-402 is being co-developed in collaboration with BioInvent International (Nordic Exchange: BINV).

TB-402 is a recombinant human monoclonal antibody which has shown a beneficial partial inhibition of the blood coagulation Factor VIII. Its long half life of approximately three weeks enables it to produce a stable and long-acting inhibition. This indicates well-controlled inhibition of Factor VIII activity with low risk of spontaneous bleeding, thus avoiding the possibility of overdose and the need for patient monitoring.

These unique features may be of major clinical significance, as it suggests that a product with an excellent safety profile, with ease of administration and compliance superior to alternative anticoagulants, can be developed. The preliminary results of the initial Phase I study were previously communicated in a Press Release issued September 7, 2007.

The Phase I trial presented at ASH was a randomized, single-dose, placebo-controlled, dose escalation trial in healthy male volunteers. 56 subjects were enrolled into the trial, including both younger age (18-45) and older age (55-76) volunteers. Results of the trial show that TB-402 is both safe and well-tolerated. No serious adverse events related to TB-402 were reported. In addition, there were no major bleeding complications, with the overall incidence being similar in both the TB-402 treated group and the patients who received placebo.

The pharmacokinetic analysis undertaken as part of the study confirms a prolonged half-life of approximately three weeks, which will allow for single-dose treatment in orthopaedic surgery patients and/or a once-a-month administration for long-term stroke prevention in atrial fibrillation (AF). The pharmacodynamic analysis also shows stable and long-acting anticoagulant activity. The Joint Steering Committee of ThromboGenics and BioInvent confirm their previous decision to move TB-402 into Phase II clinical development. As part of the development program, drug interaction studies will be performed in H1 2008 in parallel with the preparatory work needed to start the Phase II trial. The initial Phase II trial will be a dose-ranging clinical trial evaluating safety and efficacy (to prevent deep vein thrombosis, or DVT) in an orthopaedic surgery setting.

Professor Peter Verhamme, Department of Vascular Diseases, University of Leuven, who presented the results at the ASH meeting, commented: "The results from the first Phase I study with TB-402 show that this novel human monoclonal antibody is safe and well-tolerated, an important first step in the development of this new anticoagulant drug. Of equal importance, the results clearly indicate that TB-402 has the long half-life we predicted and a stable long-acting anticoagulant effect based on partial factor VIII inhibition. We are looking forward to starting the Phase II clinical trials, which will investigate the potential of TB-402 in the prevention of thromboembolic disorders."

Thromboembolic Disease

Thromboembolic diseases represent a major unmet medical need. The annual sales of anticoagulants (drugs that prevent blood clots) worldwide are over $5 billion. Nevertheless, available anticoagulants are still inconvenient and associated with a high 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.

Prevention and Treatment of Venous Thromboembolic disease (VTE)

Venous thromboembolic disease (deep vein thrombosis (DVT), pulmonary embolism) represents a major health issue, with an incidence of 1 to 3 per 1000 individuals per year and a high early mortality rate. One of the risk factors for VTE is major orthopaedic surgery. Anticoagulation prophylaxis is therefore indicated in this setting. In addition, in patients who develop a VTE, anticoagulation treatment for at least 6 months is indicated. Therefore, an agent allowing for once-a-month treatment in an outpatient setting is foreseen as an important option for the treatment of VTE.

Stroke Prevention in Atrial Fibrillation (AF)

Atrial fibrillation (AF), which is a strong risk factor for ischemic stroke, is the most common sustained arrhythmia observed in clinical practice. The prevalence of AF is estimated at 0.4% of the general population and increases with age, rising to 8.8% in the group aged 80-89 years. Given the aging population in the U.S. and other developed countries, the overall prevalence of AF is expected to continue to grow over the next several decades.

About ThromboGenics

ThromboGenics is a biotechnology company focused on discovery and development of biopharmaceuticals for the treatment of a range of vascular and eye diseases. The Company has several programs in Phase II clinical development including microplasmin, which is being evaluated as a treatment for vitreoretinal disorders and as a thrombolytic agent for vascular occlusive diseases, including acute stroke. ThromboGenics is also developing novel antibody therapeutics in collaboration with BioInvent International; these include TB-402 (Anti-Factor VIII), scheduled to enter Phase II clinical development in 2008, and TB-403 (Anti-PlGF), which is expected to proceed to Phase I clinical trials by the end of 2007. ThromboGenics has built strong links with the University of Leuven and has exclusive rights to certain therapeutics developed at the University. 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

Important information about forward-looking statements

Certain statements in this press release may be considered "forward-looking". Such forward-looking statements are based on current expectations, and, accordingly, entail and are influenced by various risks and uncertainties. The Company therefore cannot provide any assurance that such forward-looking statements will materialize and does not assume an obligation to update or revise any forward-looking statement, whether as a result of new information, future events or any other reason. Additional information concerning risks and uncertainties affecting the business and other factors that could cause actual results to differ materially from any forward-looking statement is contained in the prospectus.

SOURCE ThromboGenics NV