Samarium-153-Lexidronam complex for treatment of painful bone metastases in hormone-refractory prostate cancer.
OBJECTIVE
A Phase III randomized trial was designed to assess the effectiveness of samarium-153 (153Sm)-lexidronam for palliation of bone pain in patients with hormone-refractory prostate cancer.


METHODS
A total of 152 men with hormone-refractory prostate cancer and painful bone metastases were enrolled in a prospective, randomized, double-blind trial comparing radioactive (153Sm) versus nonradioactive (152Sm) lexidronam complexes. Patients were randomized (2:1) to the radioactive (153Sm) agent. Patient diaries recording daily pain and analgesic use were completed during a planned 16-week evaluation period. Nonresponders were informed of the treatment received after 4 weeks of treatment and, if initially treated with placebo, were allowed to receive 153Sm-lexidronam in an open-label fashion. Pain was measured using validated patient-derived visual analog scales and pain descriptor scales.


RESULTS
153Sm-lexidronam had positive effects on measures of pain relief compared with placebo within 1 to 2 weeks. Reductions in opioid use were recorded at weeks 3 and 4. Because nonresponders were unblinded at week 4, statistical comparisons between the arms beyond week 4 were not possible. Mild, transient bone marrow suppression was the only adverse event associated with 153Sm-lexidronam administration. The mean nadir white blood cell and platelet count (3 to 4 weeks after treatment) was 3800/microL and 127,000/microL, respectively. Counts recovered to baseline after approximately 8 weeks. No grade 4 decreases in either platelets or white bloods cells were documented.


CONCLUSIONS
These findings demonstrate that 1 mCi/kg 153Sm-lexidronam is both safe and effective for the palliation of painful bone metastases in patients with hormone-refractory prostate cancer.
Sartor
Oliver
O
Louisiana State University Medical Center, New Orleans, Louisiana, USA.
Reid
Robert H
RH
Hoskin
Peter J
PJ
Quick
Donald P
DP
Ell
Peter J
PJ
Coleman
Robert E
RE
Kotler
Jon A
JA
Freeman
Leonard M
LM
Olivier
Pierre
P
D000368:Aged; D000369:Aged, 80 and over; D001847:Bone Diseases / Q000188:drug therapy* / Q000209:etiology; D001859:Bone Neoplasms / Q000188:drug therapy / Q000556:secondary*; D004311:Double-Blind Method; D004338:Drug Combinations; D006801:Humans; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000627:therapeutic use*; D009943:Organophosphorus Compounds / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement; D011446:Prospective Studies; D011471:Prostatic Neoplasms; D011868:Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D012493:Samarium / Q000009:adverse effects / Q000627:therapeutic use*
D004338:Drug Combinations; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D011868:Radioisotopes; D012493:Samarium