The Company actively pursues a policy of seeking patent protection, both in the United States and abroad, for its proprietary technology. The Company has a diverse patent portfolio for its products, currently consisting of 61 issued United States patents (5 of the Company's earliest patents have now expired) and 200 issued foreign patents, with 51 United States patent applications pending, of which 5 have been allowed, and 134 foreign patent applications pending, of which 18 have been allowed.

The Company's patents contain claims covering its current in vivo cancer imaging products, as well as imaging and therapy products currently under development.

RECENT AWARDS

September, 1999, the Company was issued a U.S. patent covering an improvement in a pretargeting system that enhances the delivery of diagnostic or therapeutic drugs to a target site, which could be a cancer or an infection, by using a second step clearing agent to remove the non-targeted agent from the blood.

January, 2000, a U.S. patent was issued to the Company describing a method of radiolabeling proteins by use of a new radiometal-binding compound comprised of mercaptobutyryl glycinate ligands.

January, 2000, the Company was allowed a U.S. patent covering new methods of treating cancers by a two-step process involving bispecific fusion proteins. The fusion proteins are engineered molecules designed to have two binding ends, one that binds to the cancer and the other to a second, complementary agent.

February, 2000, the Company was awarded two U.S. patents for therapeutic radiopharmaceuticals. The first describes new methods of linking phosphorus-32 and phosphorus-33 to diverse disease targeting proteins, such that they retain the ability to bind to abnormal cells. The second patent describes a general method of labeling proteins with a radioisotope, providing a one-vial kit, and is especially useful for linking Cu-67, Hg-197, Pb-203, Ag-111 and Bi-212 to antibodies, drugs, cytokines, enzymes, hormones and immune modulators.

February, 2000, the Company was awarded a U.S. patent covering positron emission tomography (PET) with gallium-68 (Ga-68) chelates, using bispecific fusion proteins as the delivery agent.

March, 2000, the Company was awarded a U.S. patent covering the method of using very small portions of antibodies that bind to diseased tissues for better detection during surgical, endoscopic and laparoscopic procedures.

April, 2000, the Company was awarded a U.S. patent for a new therapeutic method involving cell-specific cytokines, such as IL-15, to be bound with a therapeutic isotope or RNase. The patent also covers the use of a bispecific antibody that recognizes a cancer cell and also a region of IL-15, permitting delivery of the IL-15 conjugated to RNase to the cancer cell.

Among the foreign patents issued to the Company this fiscal year were two important Japanese patents, the first covering humanized antibodies and immunoconjugates specific for B-cell lymphoma and leukemia cells which are important for the Company's lymphoma diagnostic and therapeutic products, the second covering the highly specific anti-CEA antibodies used in the Company's colorectal cancer diagnostic and therapeutic products and having potential use for other types of cancer.