Radiopharmaceutical plus Chemotherapy Effective in Advanced Prostate Cancer

A treatment combination consisting of repetitive doses of the radiopharmaceutical 153Sm-EDTMP (Quadramet®) plus the chemotherapy agent docetaxel (Taxotere®) appears to be a promising therapeutic option for men with prostate cancer that has spread to the bone. These results were recently published in the journal Cancer.

The bone is a common site to which cancer spreads (metastasizes) in advanced prostate cancer. For men with bone metastases, treatment is aimed at improving length of survival and quality of life.

Serious complications can occur with bone metastases, referred to as skeletal events. These may include bone fractures, spinal compression, extreme pain, paralysis and ultimately the potential of a compression leading to death.

Radiopharmaceuticals are drugs that are attached to a radioisotope. The radioactive isotope emits radiation in the body to the cells in which it comes into contact, as well as nearby cells.

153Sm-EDTMP is a radiopharmaceutical that tends to collect in cancerous areas of bone. Once attached to these regions, the radiation emitted tends to kill the cancer cells in this area. Researchers continue to evaluate the effectiveness of radiopharmaceuticals in the treatment of bone metastases.

In an effort to further explore 153Sm-EDTMP in prostate cancer, researchers from Memorial Sloan-Kettering Cancer Center conducted a trial to evaluate 153Sm-EDTMP plus chemotherapy in men with bone metastases from prostate cancer. The trial included 30 men with at least 3 sites of bone metastases who had stopped responding to hormone therapy. Patients were treated with repetitive doses of both 153Sm-EDTMP and docetaxel, until they were not able to tolerate therapy or they had evidence of progression of their cancer.

Median overall survival was 14.3 months.
The median survival with no evidence of disease progression was 7 months.
Treatment was generally well-tolerated, with low levels of platelets being the most severe side effect.
The researchers concluded that “preliminary efficacy supports the strategy of combining a radiopharmaceutical with chemotherapy, which is an appealing strategy” among men with bone metastases from prostate cancer that has stopped responding to hormone therapy.

Reference: Autio K, Pandit-Taskar N, Carrasquillo J, et al. Repetitively dosed docetaxel and 153samarium-EDTMP as an antitumor strategy for metastatic castration-resistant prostate cancer. Cancer. 2013;119 (17):3186–3194.