Background: To evaluate treatment by thalidomide and identify predictive factors of survival, event free survival and response among patients with advanced multiple myeloma treated with thalidomide as single agent therapy.
Patients and treatment: Patients with advanced multiple myeloma (n=83) were treated with an oral dose of thalidomide (median 400 mg/day). At start of treatment, all patients had active disease and 58 (69%) had received at least one autologous transplantation.
Results: With a median follow-up of 338 days (range, 247-629 days), 52 patients are alive, whereas 31 died between 8 and 150 days after the first administration of thalidomide. The response to thalidomide was considered as major in 11 patients (13%), partial in 29 patients (35%) and minor in 15 patients (18%), giving a total response rate of 66% (54 out of 83 patients). Thirteen patients had stable disease and 15 patients progressed. In multivariable analysis, age greater than 60 years, short interval between diagnosis and onset of thalidomide, requirement for red blood cell transfusion, IgA isotype, platelets' count <80 x 10(9)/l and serum albumin level <30 g/l at the start of thalidomide were associated with poor outcome. These three last factors produced a simplified prognostic model for patients with advanced myeloma and treated with thalidomide. Thus, among the 38 patients without any of these unfavorable risk features, one-year overall survival and event free survival were 87% and 78%. By contrast, the 43 patients with at least one unfavorable feature had one-year overall survival and event free survival of 40% and 32%, respectively (Log-Rank, P=0.0002 for both). Patients who received > or =34.4 g of thalidomide in the first 90 days of treatment had a better outcome than those who received <34.4 g. However, the mean received daily dose of thalidomide in the first 90 days has not been found to influence survival, event free survival or response. Short-term side effects of thalidomide were generally moderate.
Conclusion: Thalidomide is an effective treatment for patients with advanced myeloma, in particular, who have no poor-risk features. The poor results achieved by the other patients emphasize the need for prospective protocols using thalidomide in combination, especially with dexamethasone. In addition, further studies are needed to determine the optimal thalidomide dose and duration.