PAION's Desmoteplase May Also Be Useful in Haemorrhagic Stroke; Presentation of Research Results at International Scientific Conference in San Diego.

AACHEN, Germany -- Priv. Doz. Dr. R. Thiex, senior neurosurgeon in the Department of Neurosurgery at Aachen University Hospital reported on new results on applying PAION's clot busting drug Desmoteplase in a large animal model of haemorrhagic stroke at the 18th International Congress on Fibrinolysis and Proteolysis in San Diego, CA (USA) (Thiex R, Weis J, Schwartz O, Krings T, Rohde V: Minor Edema Formation after DSPA-induced Clot Lysis of Experimental Intracerebral Hemorrhage. J Int Soc Thromb Haem Vol 4, Suppl I, 2006, p.118). According to the scientists, the findings indicate that Desmoteplase's positive properties may also help in treating this life-threatening condition.

Stroke is the third leading cause of death in the industrialised world. Average mortality in stroke is reported to be 20-30% - however in its most threatening form, a haemorrhagic stroke or massive bleeding into the brain, mortality rates are up to 50% and long-term disability is more prominent than in ischaemic stroke which is caused by a blocked artery. Current treatment of haemorrhagic stroke is mainly symptomatic and it is difficult to improve outcome for patients. One of the clinical implications of a brain haemorrhage is that blood compresses the brain. Consequently, the affected brain area dies and therefore neurosurgeons - as a last measure - open the skull and remove the haematoma. Alternatively, following a strategy first tried by clinical investigators more than 20 years ago, a catheter can be inserted into the haematoma using stereotaxy via a small hole in the skull with subsequent administration of a drug that dissolves the partially clotted blood. The liquefied clot is then drained off via the catheter. This minor invasive treatment may prove to be faster and more effective as compared with surgery. To explore this hypothesis, the clot-dissolving drug rt-PA is currently being administered in patients.

However, one reported side effect of removing the clot by either method is brain oedema, which may be caused by endogenous t-PA's and rt-PA's neurotoxic properties. Animal studies of t-PA-assisted clot removal revealed that t-PA is associated with brain oedema and inflammation of the surrounding tissue. Other animal studies demonstrated that PAION's drug candidate Desmoteplase is not associated with such toxicity and even could antagonize t-PA neurotoxicity. Based on these findings, the research group of Priv.-Doz. Dr. Thiex at Aachen University Hospital tested Desmoteplase in an animal model of haemorrhagic stroke. In these experiments, an artificial haemorrhage is simulated by blood injection into the brain, ultimately leading to clot formation. Desmoteplase or rt-PA, respectively, was instilled locally to allow aspiration of the liquefied clot.

As presented at the conference on 31 August, Desmoteplase showed less brain oedema and less inflammation than rt-PA when investigated up to ten days after induction of experimental haemorrhage. The research work was sponsored by PAION.

Stated PAION's CMO, Dr. Mariola Soehngen: "These interesting results support previous findings regarding Desmoteplase's unique properties with regard to the central nervous system. We will now start to evaluate whether a clinical programme in haemorrhagic stroke is feasible".

About stroke

Stroke is the third leading cause of death in the industrialised world and a leading cause of serious, long-term disability. In the US alone, 700,000 people suffer from a stroke attack each year, and around 20% of them die within four weeks. For the US, the American Stroke Association expects the financial burden of stroke due to in-hospital costs, long-term care programs and productivity losses to be 58 billion dollars in 2006 alone.

About Desmoteplase

Desmoteplase, the most specific plasminogen activator known today, is a genetically engineered version of a clot-dissolving protein found in the saliva of the vampire bat Desmodus rotundus. Desmoteplase is partnered with Forest Laboratories, Inc. and H. Lundbeck A/S and currently being tested in an international multi-centered Phase III study for the treatment of acute ischaemic stroke between 3 and 9 hours after onset of symptoms. It has received fast-track designation from the U.S. Food and Drug Administration.

About PAION

PAION is a public biopharmaceutical company based in Aachen, Germany (Frankfurt Stock Exchange, Prime Standard, ISIN DE000A0B65S3). It aims to become a leader in developing and marketing innovative drugs for the treatment of stroke and other thrombotic diseases for which there is a substantial unmet medical need. PAION's activities are focused on the development of the three drugs Desmoteplase, Enecadin and Solulin. Currently PAION employs more than 75 people.