Immunomedics, Inc. announced results from recent studies of the company's proprietary, humanized antibody, hRS7 (IMMU-112), which demonstrated that when the compound is labeled with iodine-131 using a new, residualizing method patented by Immunomedics, an almost ten-fold increase in uptake and retention was observed in human breast cancer growing in mice, as compared to results obtained with the same antibody conjugated with I-131 using conventional methodology.

The new approach resulted in a radiation dose to the tumour that was 4.3-times higher than the conventional radioiodinated antibody, and resulted in significantly greater inhibition of tumour growth in the animals. "Complete remissions were observed in 5 of 11 mice, compared to only 1 of 11 in the group treated with the conventional radioiodinated antibody," observed Dr SV Govindan, senior author of the paper and a senior chemist at Immunomedics.

Cynthia L Sullivan, president and CEO of Immunomedics, stated: "This new antibody targets breast, and other solid tumours, such as prostate, lung and ovarian cancers. As reported at this meeting, this novel I-131 conjugate appears to be a promising new agent for the radioimmunotherapy of breast cancer, showing high therapeutic activity in this preclinical model. While there is still a great deal of further testing to be done, we are very pleased with the results to date and intend to continue the development of this new cancer therapeutic."

Immunomedics is a biopharmaceutical company focused on the development, manufacture and commercialization of diagnostic imaging and therapeutic products for the detection and treatment of cancer and other serious diseases. Integral to these products are highly specific monoclonal antibodies and antibody fragments designed to deliver radioisotopes and chemotherapeutic agents to tumours and other sites of disease.

Immunomedics has nine therapeutic product candidates in clinical or near clinical development and has two marketed diagnostic imaging products. The most advanced therapeutic product candidates are Lymphocide (epratuzumab), for which certain Phase II clinical trials for the treatment of non-Hodgkin's lymphoma have already been completed, and CEA-Cide (labetuzumab), which is in Phase I/II clinical trials for the treatment of certain solid tumours.