PRINCETON, N.J., June 3 /PRNewswire-FirstCall/ -- Cytogen Corporation (Nasdaq: CYTO - News) today announced interim results from a phase I clinical trial of QUADRAMET® (samarium Sm-153 lexidronam injection) in combination with bortezomib (Velcade®, Millennium Pharmaceuticals, Inc.) in patients with multiple myeloma whose cancer has relapsed following prior treatment. The findings from the ongoing phase I study indicate that the combination regimen, known as VELSAM, was well tolerated at doses studied to date and demonstrated antitumor activity, with 50 percent of patients experiencing a response or achieving stable disease. Results were presented at the 42nd Annual Meeting of the American Society of Clinical Oncology (ASCO) taking place this week in Atlanta, Georgia.