TB-402 demonstrates superior antithrombotic activity to enoxaparin

Lund, Sweden and Leuven, Belgium | May 6, 2010 | BioInvent International AB (OMXS: BINV) and ThromboGenics NV (Euronext Brussels: THR) announce today positive results from their Phase II trial of TB-402. TB-402 is a novel, long acting anticoagulant that is being developed as a single injection for the prevention of venous thromboembolism (VTE) following orthopaedic surgery. The Phase II results demonstrate that TB-402 has superior antithrombotic activity to enoxaparin (Lovenox®: sanofi-aventis) with comparable safety. Enoxaparin is currently the standard treatment to prevent VTE in this setting. Venous thromboembolism encompasses both deep venous thrombosis (DVT) and pulmonary embolism (PE).

The Phase II trial was a multicenter, dose-escalating, randomised, open-label trial, evaluating TB-402 against enoxaparin for the prophylaxis of VTE after knee surgery. All patients received enoxaparin 40 mg pre-operatively. Post operatively, patients were randomized in a sequential cohort design to one of three doses of TB-402 (0.3 mg/kg, 0.6 mg/kg or 1.2 mg/kg) or enoxaparin 40 mg (3:1; n=75 per group).

TB-402 was administered as a single intravenous bolus injection 18–24 hours after orthopaedic surgery, whereas enoxaparin was given as a 40 mg subcutaneous injection once daily for a period of at least 10 days. The primary efficacy endpoint was based on measuring all occurrences of VTE in patients by Day 7-11, whether they were symptomatic or asymptomatic. The primary safety endpoint was the number of patients with major or clinically relevant non-major bleeding from randomisation until the end of the study at 3 months. The study enrolled a total of 316 patients across 30 centers in Europe.

For the pooled TB-402 treated group, 47 out of 218 (or 22%) patients experienced VTE; for the enoxaparin treated group, 30 out of 77 (or 39%) patients experienced VTE (p<0.05). The difference of reduction between the two groups is statistically significant. The study also showed that TB-402 and enoxaparin had a similar safety profile.

The results of this trial (“Single intravenous administration of TB-402 for the prophylaxis of VTE after total knee replacement surgery”) will be presented by Prof. Peter Verhamme (University of Leuven, Belgium) at the 21st International Congress on Thrombosis on July 8 in Milan, Italy.

Svein Mathisen, CEO of BioInvent, commented, “We are delighted with the progress of TB-402 and are excited about the product’s demonstrated success over current treatments in preventing VTE in post-operative patients and the associated advantages of this being delivered as a single dose. These results underpin our belief that this novel approach will find a solid place in the anticoagulation market.“

Patrik De Haes, CEO of ThromboGenics, also commented, “It is very clear that VTE is a major clinical problem that carries considerable costs both to patients and healthcare providers. These exciting results show that TB-402 when given as a single post-operative injection could dramatically reduce the incidence of VTE. This would clearly be a major step forward in preventing this potentially life threatening condition. These results also reinforce our confidence that we can secure a significant partnership deal that will allow us to bring TB-402 to market and deliver its significant potential.”

About TB-402

TB-402 has the potential to be a very important new entrant into the anticoagulant market. TB-402 is a recombinant human monoclonal antibody that partially inhibits Factor VIII, a key component of the coagulation cascade. This novel mode of action is expected to reduce the risk of undesirable bleeding events, even at high doses, as well as the need for patient monitoring. These are the two main drawbacks associated with current anticoagulant therapy. In addition, TB-402 is a long-acting agent, which means it could be given as a single dose to prevent the development of DVT in patients undergoing surgery. This simple approach to prophylaxis would be an attractive option, as all current anticoagulant treatment options require daily treatment for up to several weeks.

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 600,000 patients are treated for venous thromboembolisms (VTE) such as DVT or pulmonary embolism (PE) each year.(1)Moreover, DVT and PE together may be responsible for more than 100,000 deaths in the U.S. each year.(2)

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.(3)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.

About BioInvent

BioInvent International AB, listed on the NASDAQ OMX Stockholm (BINV), is a research-based
pharmaceutical company that focuses on developing antibody drugs. The Company currently has four clinical development 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-Abelló, Bayer HealthCare, Daiichi Sankyo, ImmunoGen, Mitsubishi Tanabe, OrbusNeich, UCB and XOMA.

More information is available at www.bioinvent.com.

About ThromboGenics

ThromboGenics is a biopharmaceutical company focused on the discovery and development of innovative medicines 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 conditions. In addition, ThromboGenics is 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.

(1)Barclays Capital Equity Research Report on New Anticoagulants, August 5, 2009
(2)“The Surgeon General’s Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism,” September 15, 2008, p.1.
(3)“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 is headquartered in Leuven, Belgium. The Company is listed on Eurolist by Euronext Brussels under the symbol THR. More information is available at www.thrombogenics.com.

SOURCE: BioInvent International AB