n PRINCETON, NJA single dose of Quadramet (Samarium Sm 153 Lexidronam injection) significantly relieved bone pain in patients with metastatic breast, prostate, and other primary cancers in a dose-dependent manner, a multicenter European study has shown.
The trial was sponsored by Cytogen, manufacturer of Quadramet, and the lead investigator was Isabella Resche, MD, of the Centre Rene Gauducheau, Nantes, France.
The double-blind trial randomized 114 cancer patients with painful bone metastases to receive a single Quadramet dose of either 0.5 mCi/kg or 1.0 mCi/kg.
During the first 4 weeks after administration, patients made daily assessments of their pain intensity, daytime discomfort, and quality of sleep. During week 4, the primary efficacy timepoint of the study, there was a significant difference in pain relief between the two doses in favor of the higher dose (European J Can, October 1997).
A predictable level of dose-related bone marrow suppression was associated with Quadramet treatment. Platelet and white blood cell counts reached their nadirs at weeks 3 or 4 with both doses and recovered to normal levels by week 8.
The study also showed a survival advantage for the higher dose in breast cancer patients. The 20 breast cancer patients who received 1.0 mCi/kg had, on average, a one-year longer survival than the 16 breast cancer patients who received 0.5 mCi/kg of the drug. No similar survival difference was observed between the two Quadramet doses among the prostate cancer patients.
The interesting findings regarding survival in breast cancer patients will clearly prompt additional studies of Quadramet in this disease, commented Dr. Graham S. May, vice president of medical affairs for Cytogen, manufacturer of Quadramet.