Bortezomib Plus Dexamethasone as the Induction Therapy in Newly Diagnosed Multiple Myeloma Patients: A Phase II Study in Thai Patients

Abstract

Abstract:

We conducted a phase II study using bortezomib plus dexamethasone (Vel/Dex) as the induction therapy in fifteen consecutive newly diagnosed myeloma patients who were eligible for autologous stem cell transplant. Bortezomib 1.3 mg/m2 was administered on days 1, 4, 8 and 11, along with dexamethasone 40 mg orally on day 1-4 and 8-11 of a 21-day cycle for 4 cycles. Twelve male and three female patients were enrolled; the median age was 60 years. Of the 14 evaluable patients, 6 patients (42.9%) achieved complete remission after 4 cycles of Vel/Dex. The overall response rate was 85.8%. Nine patients received DCEP chemotherapy for stem cell mobilization with the median number of CD34+ cells collected of 11.4 x 106/kg. Eight patients successfully underwent upfront autologous stem cell transplant (ASCT). At the time of this analysis, four patients have died from progressive disease. Twoyear overall survival of the whole group was 73.3%. Vel/Dex regimen was very well tolerated. Only one patient was not able to complete 4 cycles. Most common grade 3 or 4 toxicities were anemia (46%) and thrombocytopenia (33.3%). Other serious adverse events were colonic pseudoobstruction (1 case), pneumonia (2 cases) and staphylococcal endocarditis (1 case). We conclude that Vel/Dex is a highly active induction regimen for newly diagnosed myeloma patients who are planned for high-dose therapy and ASCT.