Tandem transplants with different high‐dose regimens improve the complete remission rates in multiple myeloma. Results of a Grupo Español de Síndromes Linfoproliferativos/Trasplante Autólogo de Médula Ósea phase II trial

Abstract

Summary. Between 1994 and 1999, 88 multiple myeloma (MM) patients were included in a phase II study to evaluate a tandem autologous stem cell transplantation (ASCT) programme. The first was conditioned with melphalan 200 mg/m² (MEL200‐ASCT1), and the second with cyclophosphamide, etoposide and BCNU (CBV‐ASCT2). All patients were in response after MEL200‐ASCT1. A control group of MM patients with response to a single ASCT was selected to compare outcomes. After MEL200‐ASCT1, 26 patients (30%) achieved complete remission (CR). Of the remaining 48 evaluable patients, 16 (33%) achieved CR with CBV‐ASCT2. The final CR rate was 48%. The 5‐year survival (OS) was 55%[95% confidence interval (CI) 43–67%] while the event‐free survival (EFS) was 28% (95% CI 15–39%). CR status after CBV‐ASCT2 was the most important prognostic factor for OS and EFS (P = 0·00001), although no differences in outcomes were detected when the patients in CR after MEL200‐ASCT1 were compared with those who obtained CR after CBV‐ASCT2. Univariate and multivariate analyses showed improved OS and EFS for the tandem series as compared with the control series treated with a single MEL200‐ASCT. However, in a stratified comparison by response, there were no prognostic differences between tandem patients and control patients treated with a single ASCT. In summary, our study suggests that the benefit of a second high‐dose therapy course depends on its capacity to result in CR for MM patients who have not attained CR after ASCT1.