Treatment of Waldenstrom's macroglobulinemia with single-agent thalidomide or with the combination of clarithromycin, thalidomide and dexamethasone

To evaluate the activity of thalidomide in Waldenstrom's macroglobulinemia (WM), 20 patients were treated on a dose schedule that escalated from 200 mg/d to 600 mg/d. On an intention-to-treat basis, five (25%) patients achieved a partial response, which was noted within 3 months of treatment. Adverse effects were common and prevented dose escalation of thalidomide in 75% of patients and led to premature discontinuation of treatment in 35%. We subsequently evaluated the oral combination of clarithromycin (500 mg twice per day), low-dose thalidomide (200 mg once daily), and dexamethasone (40 mg once per week). Our preliminary analysis on 12 previously treated patients indicate activity of this regimen in WM: three patients achieved a partial response and two patients demonstrated monoclonal protein reduction of greater than 25%. This combination was associated with a variety of side effects due not only to thalidomide, but also to corticosteroids and to clarithromycin. Our preliminary data indicate that this combination may be a useful salvage regimen for some patients with heavily pretreated macroglobulinemia.