Cytogen Corporation has announced the publication of new data relating to the company's Quadramet (samarium Sm-153 lexidronam injection) product. The publication, "Incident pain and analgesic consumption decrease after samarium infusion: a pilot study" appears in a recent issue of the peer-reviewed journal Supportive Care in Cancer (Support Care Cancer. 2006 Sep 12).

While a number of controlled and uncontrolled studies have demonstrated that Quadramet is active in the relief of pain associated with metastatic bone lesions deriving from several tumour types in 73 per cent to 86 per cent of patients treated, no prospective studies specifically assessed the role of this class of drugs in preventing or reducing movement-related pain (incident pain). Incident pain is the most frequent pain in patients with cancer progression to bone.

In the study conducted by independent investigators, thirteen patients with hormone refractory prostate cancer and painful bone metastases received a single 1 mCi/kg dose of Quadramet. Variation of pain intensity on movement and at rest was measured by both a six-point Verbal Rating Scale (VRS) and reduction of analgesic drug consumption at week four following Quadramet infusion.

Pain intensity on movement at week four improved by at least two points on the VRS in eight of the eleven patients (72.7 per cent) who reported such pain at baseline. In a similar manner, for patients with pain at rest, seven of the eleven patients (63.6 per cent) reported an improvement of at least two points on the VRS. Nine out of ten patients who were taking analgesics at baseline reported a reduction in the consumption of drugs administered on a regular basis or as rescue doses.

"Incident pain or movement-related pain is considered a subtype of breakthrough pain which is particularly difficult to treat in patients with metastatic bone disease," said William Goeckeler, PhD, senior vice president of operations at Cytogen. "Reduction in pain not only at rest but that which occurs with movement, as reported in this study, emphasizes the value of Quadramet as an important option for pain palliation. The decreases in consumption of analgesic medications observed along with the reduction in pain scores provide additional evidence of benefit for these patients."