The clinical impact of thalidomide maintenance after autologous stem cell transplantation in patients with newly diagnosed multiple myeloma in real clinical practice of Korea

In real clinical settings (not clinical trials), thalidomide has been accepted as maintenance therapy to patients with multiple myeloma (MM) because of the cost of drugs, the limitations of medical insurance, etc., in our country (South Korea). The purpose of this study was to evaluate the utility of thalidomide maintenance for improving survival in transplantation-eligible patients with MM in the real clinical field. Differences in survival rates were estimated in patients treated with or without thalidomide maintenance. The 3-year progression-free survival rates (PFS) of patients with and without maintenance, respectively, were 55.4 and 37.2 % (p = 0.005). The 3-year overall survival rates (OS) were 88.0 and 84.0 % (p = 0.105). No difference in 3-year OS after relapse or progression (OS2) was observed between the two groups (50.4 and 55.3 %, p = 0.661). The 3-year PFS of patients with and without maintenance therapy who had shown less than CR after ASCT were 68.4 and 23.3 % (p < 0.001). In conclusion, Thalidomide maintenance therapy showed longer PFS in real clinical practice, and long-term use of thalidomide did not interfere with the efficacy of salvage chemotherapy in patients who experienced progression or relapse after ASCT. In addition, thalidomide maintenance might be also useful for patients who have shown less than CR after ASCT.