Alpha-interferon maintenance treatment is associated with improved survival after high-dose treatment and autologous stem cell transplantation in patients with multiple myeloma: a retrospective registry study from the European Group for Blood and Marrow Transplantation (EBMT)

The purpose of this study was to evaluate the effect of alpha-IFN maintenan ce treatment after autologous stem cell transplantation (ASCT) for multiple myeloma in a retrospective registry analysis. 473 patients with multiple m yeloma who received IFN maintenance treatment ASCT were compared with 419 p atients who did not receive IFN-treatment, Patients who were evaluable for response and in complete or partial remission at 6 months after ASCT were e ligible, after excluding patients with graft failure. Cox proportional haza rds assumptions were checked and handled by stratification. The prognostic variables unevenly distributed between the two groups were statistically co rrected for in the Cox analysis. 391 patients reached complete remission (C R) after ASCT (203 in the IFN group and 188 in the no-IFN group) and 501 we re in partial remission (PR, IFN 270, no-IFN 231), Overall survival (OS) an d progression-free survival (PFS) were significantly better in the IFN-grou p (OS, 78 vs 47 months, P=0.007, and PFS, 29 vs 20 months, P=0.006, respect ively). The difference in OS and PFS was most strongly pronounced in the PR patients. 209 patients have died (IFN, 84; no-IFN, 125), Progressive myelo ma was the cause of death in 94% of the IFN-treated patients and in 83% of the no-IFN group (P=NS), Thus, IFN maintenance treatment after ASCT was ass ociated with better OS and PFS, Treatment seemed to be most beneficial in p atients who did not achieve CR, The difference in median survival was as lo ng as 2.5 years, and although part of this difference is attributable to di fferences in other prognostic factors, it might justify possible difference s in quality-of-life due to adverse effects of interferon treatment.