Palliation of pain associated with metastatic bone cancer using samarium-153 lexidronam: a double-blind placebo-controlled clinical trial.

PURPOSETo evaluate the effectiveness and safety of samarium-153 (153Sm) lexidronam (EDTMP) in a double-blind, placebo-controlled study.PATIENTS AND METHODSPatients with painful bone metastases secondary to a variety of primary malignancies were randomized to receive 153Sm-EDTMP 0.5 or 1.0 mCi/kg, or placebo. Treatment was unblinded for patients who did not respond by week 4, with those who had received placebo eligible to receive 1.0 mCi/kg of active drug in an open-label manner. Patient and physician evaluations were used to assess pain relief, as was concurrent change in opioid analgesia.RESULTSOne hundred eighteen patients were enrolled onto the study. Patients who received 1.0 mCi/kg of active drug had significant reductions in pain during each of the first 4 weeks in both patient-rated and physician-rated evaluations. Pain relief was observed in 62% to 72% of those who received the 1.O-mCi/kg dose during the first 4 weeks, with marked or complete relief noted in 31% by week 4. Persistence of pain rel...