The escalating dose clinical study will evaluate both the safety profile and effects on painful symptoms and analgesic use. In addition, preliminary information regarding the effect of Quadramet on the underlying disease will be determined by monitoring levels of M-protein, a marker for multiple myeloma activity. This new clinical trial is based in part on previously reported results from a single arm phase II trial conducted by independent investigators in Europe, that evaluated the efficacy of Quadramet and zoledronic acid (Novartis' Zometa), a third-generation bisphosphonate, for the treatment of symptomatic refractory elderly multiple myeloma patients. In that study, patients were asked to quantify their pain using a visual analogue scale (ranked 0-10, with zero representing no pain and ten representing the highest level of pain). At baseline, the median pain rating was seven. After treatment with Quadramet and zoledronic acid, the median pain rate was reduced to two with no need for analgesics at a median follow-up period of 14 months. Interestingly, M-component level, a marker for multiple myeloma activity, decreased more than 25% in half of patients and was still stable at 19 months follow-up. "Current clinical data suggest that a bone targeted approach may represent a potentially useful added component for the treatment of multiple myeloma," said Dr William Goeckeler, senior vice president of operations at Cytogen. "We expect to initiate additional studies throughout 2005 that are designed to systematically evaluate Quadramet's potential role as a targeted oncology product in various settings, including both higher dose applications and in combination with a variety of other synergistic agents." Quadramet is an oncology product that pairs the targeting ability of a small molecule, bone-seeking phosphonate, with the therapeutic potential of radiation. Combined, these agents form an innovative molecule that selectively concentrates in areas of new bone formation.