Bone metastases treatment by sm-153 oxabifore in combination with monoclonal antibody denosumab (xgeva).

To the Editor,

A recent report on “bone metastases treatment by samarium (sm)-153 oxabifore in combination with monoclonal antibody denosumab (Xgeva)” is very interesting.[1] Rasulova et al. noted that “combined treatment of bone metastases with sm-153 oxabifore and denosumab is effective and safe.[1]” In fact, the combination is very interesting. A similar observation was also reported by Rasulova et al. on another combination between sm-153 oxabifore and bisphosphonate. Focusing on the present combination, sm-153 oxabifore and denosumab, the issue of side-effect should be studied in a larger scale. In fact, denosumab is generally used for management of bone loss in cancer patients.[2] However, some interesting side-effect of this drug can be seen. The important condition is osteonecrosis.[34] For sm-153, the effectiveness and side-effect is still inconclusive. The flare up of pain can be possible during therapy. As already note, further studies are still required for conclusion (see a clinical report in Russian language: base.ukgma.kz/vestnik/2012/vestnik_3_12.doc).