CYTOGEN TO ADD LOW-DOSE ONCO-SCINT STUDIES

CYTOGEN TO ADD LOW-DOSE ONCO-SCINT STUDIES to Phase I/Phase II clinical trial program, the company announced Aug. 30. FDA requested a study of dosages between 0.2 mg and 2 mg of the tumor imaging agent following a review of Cytogen's clinical data at a mid-August meeting at FDA headquarters in Rockville, Maryland. To date, Cytogen has conducted Phase I and Phase II clinical trials on more than 80 patients using dosages containing 0.2, 2 and 20 milligrams of monoclonal antibody conjugate. Preliminary results of the study showed insignificant differences between 2 and 20 milligram dosages, the company said. The extended study will take place at some of the 20 sites now involved in PhaseI/Phase II testing and will include an additional 20 patients with colorectal cancer. "Although our dose-ranging studies will add approximately six months to our development program, we forsee commercializing a low dose Onco-Scint imaging agent which will provide additional patient benefits and a significant product advantage for Cytogen," said Thomas McKearn, MD, PhD, Cytogen senior vice president of scientific affairs. Cytogen reports that the lower dosage levels have reduced the formation of the human anti-mouse antibody, or HAMA, to about 8% of patients. HAMA formation can be a problem in up to 50% of patients being treated with monoclonal antibody-based products, according to the company. Onco-Scint employs Cytogen's proprietary "linker" technology to connect radio-isotopes to monoclonal antibodies for in vivo imaging of lung, breast, colorectal, ovarian, gastric and pancreatic cancer ("The Pink Sheet" June 15, 1987, T&G-1). Cytogen plans to seek FDA approval for the first Onco-Scint product for colorectal cancer imaging sometime in mid-1989, the company said. An imaging product for ovarian cancer will be next in line.