LEUVEN, Belgium and LUND, Sweden, September 7 /PRNewswire/ --

- Decision Taken to Advance Novel, Long-Acting Anticoagulant Into 
Phase II Clinical Development

ThromboGenics NV (Euronext Brussels: THR), a biotechnology
company focused on vascular disease, and co-development partner, BioInvent
International (Nordic Exchange: BINV), announce today that they have
successfully completed enrollment and initial follow-up of all volunteers in
the first Phase I trial of TB-402, which is being developed for the
prevention of venous thromboembolic disorders (VTE - blood clots).

TB-402 is a recombinant human monoclonal antibody that targets
factor VIII, a component of the coagulation cascade. This antibody is a
promising novel anticoagulant agent particularly because it only partially
inhibits factor VIII activity even when administrated in very high doses.
This may potentially decrease the risk of undesirable bleedings and the need
for monitoring, which are the main concerns associated with anticoagulants
currently on the market.

The trial, performed in Denmark, was a randomized,
single-dose, placebo-controlled, dose-escalation trial in healthy male
volunteers. 56 volunteers were enrolled into the trial, including both
younger age volunteers (18-45) and older age volunteers (55-76).

Preliminary results of the trial showed that TB-402 met both
the primary (safety and tolerability) and secondary (pharmacokinetic and
pharmacodynamic) endpoints. The drug was well tolerated and the study showed
that TB-402's prolonged half-life will allow for single-dose treatment in
orthopaedic surgery patients and/or once-a-month administration for long-term
stroke prevention in atrial fibrillation (AF), as opposed to daily treatment
with current anticoagulants. Importantly, the findings confirm that TB-402
achieves only partial inhibition of factor VIII activity without the
undesired effect of total factor VIII inactivation. Final data analysis of
the first Phase I trial will be available later this year.

Based on these results, and after a review of preliminary
results with the Scientific Advisory Board for this program, the Joint
Steering Committee of ThromboGenics and BioInvent has decided to move TB-402
into Phase II clinical development. As part of the development programme,
drug interaction studies will be performed in parallel with the preparation
for Phase II, which is expected to start in H1 2008. The initial Phase II
trial will be a dose-ranging clinical trial evaluating safety and efficacy
(ability to prevent deep vein thrombosis - DVT) in an orthopaedic surgery
setting.

Prof. Desire Collen, CEO of ThromboGenics, commenting on
today's announcement, said: "We and our co-development partner, BioInvent,
are extremely pleased to have completed the first TB-402 Phase I trial.
Initial results of the trial are very encouraging and show that TB-402 is
safe and has the potential to fill a significant unmet need in multiple major
indications by allowing for single or once-monthly administration to prevent
and treat debilitating and life-threatening conditions, such as deep vein
thrombosis and stroke secondary to atrial fibrillation. We are looking
forward to moving TB-402 into Phase II clinical trials in the first half of
2008."

Svein Mathisen, CEO of BioInvent, added, "We are very
satisfied that the trial has demonstrated that TB-402 is safe, and that it
inhibits Factor VIII as predicted. The decision to advance into Phase II
clinical development is once again evidence that our partnership is
successful, proving the synergy of ThromboGenics' knowledge within vascular
medicine and BioInvent's skills in antibody development."

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
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 also has TB-402 in Phase I
clinical development and TB-403 scheduled to enter clinical development at
the end of 2007, plus several other drug candidates in preclinical
development with preclinical proof-of-principle demonstrated. The Company 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 Ireland and the U.S.
The Company is listed on Eurolist by Euronext Brussels under the symbol THR.
More information is available at www.thrombogenics.com.

About BioInvent

BioInvent International AB, listed on The Nordic Exchange
(OMXS: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, atherosclerosis and
ophthalmic diseases. In January 2007, the Company announced a major strategic
alliance with American-based Genentech, Inc. in the cardiovascular field.
These projects are based on a competitive and in substance patented
technology platform. The scope and strength of this platform is also utilised
by partners, such as ALK-Abello, ImmunoGen, OrbusNeich, Sanofi-Aventis,
Syngenta, UCB and XOMA. The Company, which currently has 96 employees, is
located at Ideon in Lund. More information is available at www.bioinvent.com.

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.