Arsenic Trioxide with Ascorbic Acid and High-Dose Melphalan Is Safe and Effective for Autotransplantation for Multiple Myeloma

• Published in: Blood 2007-11, Vol.110 (11), p.942-942
• Main Authors: Qazilbash, Muzaffar H., Saliba, Rima M., Parikh, Gaurav, Hosing, Chitra, Mendoza, Floralyn, Qureshi, Suhail P., Weber, Donna M., Wang, Michael, Flosser, Thuy, Couriel, Daniel R., Kebriaei, Partow, Popat, Uday, Alousi, Amin, de Lima, Marcos, Champlin, Richard E., Giralt, Sergio
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V110.11.942.942

Background: Arsenic trioxide (ATO) has been shown to be synergistic with melphalan both in vitro and in vivo. We conducted a randomized phase II trial to determine the safety and efficacy of a combination of ATO, melphalan, and ascorbic acid (AA) as a preparative regimen in patients undergoing autologous hematopoietic progenitor cell transplantation for multiple myeloma (MM). We also assessed the impact of ATO levels on melphalan pharmacokinetics, engraftment, and toxicity. Methods: Forty-eight patients with secretory myeloma (23 females, 25 males; median age, 54; range 35–70) were treated between 4/04 and 8/05. All patients received melphalan 100 mg/m2 IV on days -4 and -3 and AA 1000 mg/day IV on days -9 to -3. Patients were randomized to 3 arms: no ATO (arm 1), ATO 0.15 mg/kg IV on days -9 to -3 (arm 2), and ATO 0.25 mg/kg IV on days -9 to -3 (arm 3). Twelve patients had received a prior autograft, with a median 4.5 x 106/kg (range 2.3–10.9) CD34+ cells infused. Results: Patients in all 3 arms were evenly matched. Twenty-nine patients (60%) were transplanted for consolidation of first remission and 19 patients (40%) for relapsed disease. With a median follow-up of 26 months (range 10–37) post-autograft, no dose-limiting toxicity, or nonrelapse mortality was reported. Toxicity was limited to grade 1 or 2 nausea, vomiting, and diarrhea and was comparable in all 3 arms. Melphalan pharmacokinetics was not altered by ATO pretreatment. Median time to neutrophil engraftment (absolute neutrophil count >500/dL) was 9 days, with no engraftment failures or delays in either the control or ATO arms. The complete response (CR) rate for all patients was 25% (12/48), and the partial response rate was 60% (29/48) for an overall response rate (ORR = CR + PR) of 85%. Progression-free survival (PFS) and overall survival (OS) after 24 months of follow-up were 59% and 91%, respectively. Median PFS was 29 months; median OS has not been reached. There was no significant difference in CR, ORR, PFS, or OS among the 3 arms (P =.9, .9, .5, and .6, respectively). PFS and OS were comparable among patients with chromosomal abnormalities or relapsed disease at transplant and patients undergoing a second autotransplant for salvage. Conclusions: Addition of ATO + AA to high-dose melphalan is safe and well tolerated as a preparative regimen for autotransplants in patients with MM, including high-risk patients. There was no adverse impact of ATO on engraftment. Longer follow-up is necessa