Low Dose of Thalidomid® as Effective as Higher Dose in Relapsed Myeloma

Researchers from France have reported that 100 mg/ per day of Thalidomid (thalidomide) is as effective as 400 mg per day in patients with relapsed or refractory multiple myeloma. The details of this randomized trial were presented at the 47th annual meeting of the American Society of Hematology in December 2005.

Recent studies suggest that Thalomid is one of the most active agents in patients with refractory or recurrent myeloma. Significant responses have also been reported following Thalomid treatment in patients who have relapsed after high-dose chemotherapy with stem cell support. More recent results suggest that Thalomid and dexamethasone or Thalomid, doxorubicin and dexamethasone are effective regimen for initial treatment of patients with multiple myeloma and allows adequate collection of stem cells in patients scheduled for transplantation. The major toxicities of Thalomid are deep-vein thrombosis, peripheral neurophathy and somnolence. The usual dose of Thalomid is 400 mg per day.

The researchers involved in this study sought to determine the minimal effective dose of Thalomid that would decrease side-effects without compromising efficacy. They randomly allocated 400 patients with relapsed and/or refractory myeloma to receive 100 mg or 400 mg per day of Thalomid. The median age of the patients in this study was 68 years. One hundred and nine patients in the 100 mg arm received dexamethasone compared to 90 in the 400 mg arm.

The one year survival was 73% for patients in the 400 mg arm and 69% in the 100 mg arm. Patients in the 100 mg arm had significantly less somnolence and peripheral neuropathy but there were no differences in thrombosis, which occurred in less than 5% of each arm. These researchers concluded that the lower dose of Thalomid did not compromise survival and was associated with less toxicities.

Comments: These data are of interest as larger doses of Thalomid may not be necessary at least in the palliative setting of treatment.

Reference: Yakoub-Agha I, Hulin C, Doyen C, et al. A multicenter prospective randomized study testing non-inferiority of thalidomide 100 mg/day as compared with 400 mg/day in patients with refractory/relapsed multiple myeloma: first results of the final analysis of the IFM 01-02 Study. Blood. 2005;106:110a, abstract #364.