Sequential VAD (Vincristine, Adriamycin, Dexamethasone) and VTD (VELCADE®, Thalidomide, Dexamethasone) Induction Followed by High-Dose Therapy with Autologous Stem Cell Transplantation and Maintenance Treatment with VELCADE for Newly Diagnosed Multiple Myeloma: Interim Results of Phase II Trial.

Introduction Effective reduction of myeloma before autologous stem cell transplantation (ASCT) prolongs survival in multiple myeloma patients. Recently, incorporation of novel agents resulted in improved response rate and reduced side effect in newly diagnosed multiple myeloma.

Method: Patients are planned to receive 2 cycles of VAD (vincristine 0.4mg D1-4, adriamycin 9mg/m² D1-4, dexamethasone 40mg D1-4, 9–12 every 3 weeks), and VTD (bortezomib 1.3mg/m² D1, 4, 8, 11, thalidomide 100mg daily, dexamethasone 40mg D1-4, 9–12 every 3 weeks). High dose melphalan (200mg/m²) is used as a conditioning regimen for ASCT. Bortezomib (1.3mg/m²) as a maintenance treatment is administered weekly x 4 times every 6 weeks for 4 cycles after ASCT. Response was assessed by EBMT criteria, with additional category of nCR. Adverse events were graded by the NCI-CTCAE, Version 3.0.

Result: At this interim analysis, 60 patients have been entered into the ongoing trial, and efficacy could be assessed in 53 patients. After 2 cycles of VAD, response rate was 70%. After VTD, two patients showed further improvement with additional CR, and an overall response was 97% with 14% CR. Especially, patients with poor prognostic cytogenetics (n=6) all responded after VTD. So far, autologous stem cells were successfully collected in all 28 patients with a median CD34⁺ count of 7.8 x 10⁶/kg (range, 2.17–44.7 x 10⁶/kg). In 24 patients who underwent autologous stem cell transplantation, five patients gained additional CR. There was no progression in patients completed bortezomib maintenance (n=9, CR 77%). The median follow-up duration was 6 months, median time to response was 1.4 months, and median overall survival was not reached. Grade 3,4 hematologic toxicity was more frequently observed after VAD than VTD (anemia 15.8%, 4.6%, neutropenia 7.9%, 3.5%), and incidence of grade 2,3 peripheral neuropathy was low (VAD 3.5%, VTD 7%).

Conclusion: Sequential VAD and VTD induction therapy in newly diagnosed multiple myeloma was highly effective, even in patients with poor prognostic cytogenetics, and did not prejudice stem cell collection. VTD could have contributed to increased RR and minimized side effects. An updated results will be presented at the ASH meeting.

*Protocol Number: KMM51-NCT00378755.