Thrombopoietin

Dragon is developing an engineered version of the naturally occurring human protein thrombopoietin, TPO. This protein is produced mainly by the liver and stimulates the production of blood platelets and bone marrow platelet progenitor (!!±pre-platelet!!L) cells. Platelets are critical to blood clotting and wound healing, and are often diminished in patients receiving cancer chemotherapy, or in those with liver or other relevant diseases, causing thrombocytopenia. This condition can result in uncontrolled bleeding or bruising and is currently treated by high-cost blood transfusions.

The introduction of effective and potent platelet stimulating drugs will greatly improve the treatment of thrombocytopenia and could give rise to a market worth hundreds of millions of dollars. Such products may also increase platelet levels prior to blood donation in normal donors, or in surgery patients whose own blood is used for post-surgical transfusion.

TPO products are under development. Phase I/II randomized, placebo-controlled clinical trials have shown that they increase platelet counts when used prior to or subsequent to chemotherapy. They are also generally well tolerated. Dragon!|s TPO has been tested in animals and is now ready to enter phase I clinical trials in cancer patients. Our first regulatory approvals for this product are expected in 2005.

Dragon has developed a novel system for manufacturing TPO, using Pichia yeast. We expect this technology to produce better yields of TPO than other available production systems, resulting in lower unit costs.