Monotherapy with low-dose thalidomide for relapsed or refractory multiple myeloma: better response rate with earlier treatment

BACKGROUND: Thalidomide is an immunomodulatory drug used in the treatment of relapsed or refractory multiple myeloma (MM). The optimal dosing regimen of thalidomide is not known. PATIENTS AND METHODS: We retrospectively analysed the overall response rate and response duration of 53 patients with relapsed MM who received thalidomide in a median dose of 100 mg daily. The aim of the study was to compare the response rates of thalidomide given as the second-line treatment to those of thalidomide given as the third-line therapy. RESULTS: Of 33 patients receiving thalidomide as second line, 13 (39%) had overall treatment response. Of 20 patients treated with thalidomide monotherapy as the third-line treatment, there were three treatment responses (15%) (P = 0.039). The median duration of treatment response in the second-line thalidomide group (12 months, range 6-60 months) was twice as long as that in the third-line thalidomide group (6 months, range 3-57 months), although the difference was not statistically significant, probably due to low number of patients. Only 6% of patients (3/53) had to stop the treatment because of toxicity. CONCLUSIONS: Monotherapy with low-dose thalidomide results in treatment responses in approximately 30% of patients with advanced MM. The response rate appears to be higher if thalidomide treatment is started after the first relapse or progression in comparison with the second relapse or progression. Treatment toxicity is acceptable even with prolonged exposure to the drug.