Bortezomib, Thalidomide, and Dexamethasone as Induction Therapy for Patients with Symptomatic Multiple Myeloma.

Abstract

The optimal induction regimen for patients with symptomatic myeloma who are eligible for transplantation is currently unknown. While thalidomide and dexamethasone is an effective regimen, it only has a 60 to 65% response rate and few complete responses (CR). Bortezomib based inductions have demonstrated a high response rate and an improved CR as well. Recently the IFM reported the initial results of the randomized bortezomib plus dexamethasone versus VAD induction followed by transplant, which demonstrated that fewer patients treated with bortezomib required tandem transplants. Wang et al reported a high induction response rate with the combination of BTD for only 2 cycles given over a 28 day cycle. Here we report our experience with the combination of BTD as induction therapy. 38 patients with symptomatic myeloma were treated with BTD as induction therapy. Patients received standard dose and schedule bortezomib at 1.3 mg/m2 on days 1, 4, 8, and 11 with thalidomide at 100 mg/day, and 8 days of 40 mg dexamethasone every 21 days. The median age was 58 years (38–70) with 19 males. This was first line therapy for 29 patients, second line for 7 patients and 3rd line for 2. 12 patients had ISS stage 2 and 8 had ISS stage 3. The median β2M was 3.4 (1.66–41.89). Median creatinine was 1.1 (0.6–21.0). Nineteen patients had an IgG paraprotein, 6 an IgA, and 16 patients had light chain disease. The median number of cycles administered was 4 (2–8). Fifteen patients developed neuropathy of any grade. One patient developed grade 3 neuropathy. The overall response rate (CR, VGPR, plus PR) was 92%, with 58% of patients achieving a VGPR or better, and 21% of patients achieving an immunofixation negative CR. 1 patient had a minimal response and 2 patients had progressive disease (both patients presented with plasma cell leukemia). These two patients were treated with the combination of BTD with PACE chemotherapy. One of the two died from progressive disease and the other patient remains in complete remission after high dose therapy and autologous transplantation. 29 patients had consolidation therapy with high dose melphalan and autologous peripheral blood stem cell transplantation. Eight patients have collected stem cells without proceeding with immediate consolidation therapy. After a median follow up of 373 days, median progression free survival and overall survival have not been reached. One year overall survival is 97%. One year progression free survival is 87%. In conclusion, we report a very high response rate with a short course of bortezomib, thalidomide and dexamethasone with an acceptable toxicity profile. Follow up of patients in CR treated without high dose therapy and autologous transplant is in progress. Further studies of this active regimen are warranted.