Low-dose thalidomide regimens in therapy of relapsed or refractory multiple myeloma

Thalidomide has been estimated as a useful drug in therapy of refractory or relapsed multiple myeloma. Recently, several studies have shown very good results in therapy combination of thalidomide, cyclophosphamide and dexamethasone, but still high doses of thalidomide associated with serious adverse events have been used. In our study, we performed low-dose thalidomide regimens; the aim of this study was to verify the effect and to assess their toxicity. For younger patients up to 65 years we used a "CTD-junior" regimen, consisting of oral thalidomide 200 mg daily, pulsed intravenous cyclophosphamide 800 mg on day 1 and pulsed oral dexamethasone 40 mg on days 1-4 and 12-15, for every three weeks. For patients over 65 years, the "CTDsenior" regimen was used, with oral thalidomide 50-100 mg daily (according to tolerability), oral cyclophosphamide 50 mg daily and pulsed dexamethasone 20 mg on days 1-4 and 15-18, for every four weeks. From the group of 97 patients with progressive form of multiple myeloma or with resistance to conventional chemotherapy, 85 patients were evaluated. According to the EBMT criteria, we observed in 8% complete remission (CR), in 50% partial response (PR) and in 22% minimal response (MR). Ten patients (12%) were stabilized and seven patients (8%) progressed. Toxicity of both regimens was mild and well manageable, when weakness, obstipation, neuropathy of lower extremities, glycoregulation worsening and mild leucopenia occurred most often. These results showed that low doses of thalidomide are still effective, when combined with other drugs. Both CTD regimens are safe also for patients with advanced and heavily pretreated multiple myeloma.