In February 2003, NPS Pharmaceuticals (Nasdaq: NPSP) acquired Enzon. NPS was itself previously an SBIR involved firm. Enzon is a biopharmaceutical company developing, manufacturing and marketing enhanced therapeutics for life-threatening diseases through the application of its proprietary technologies proprietary PEG (polyethelene glycol) - process enhances existing pharmaceuticals by attaching a nonreactive polymer. The modified drug then avoids the immune system's radar and lives in the blood longer, increasing effectiveness. FDA-approved products include Oncaspar, used to treat leukemia, and Adagen, an enzyme-replacement therapy for a rare, severe immunodeficiency commonly known as the "Bubble Boy Disease." Other PEG products in Enzon's pipeline include possible treatments for hepatitis C and for some types of cancers and tumors. It has marketing and research pacts with several leading drug companies, including Rhone-Poulenc Rohrer and Schering-Plough