Long-Term Clinical Outcomes of Allogeneic Stem Cell Transplantation in Multiple Myeloma

• Published in: Blood 2015-12, Vol.126 (23), p.1968-1968
• Main Authors: Zamagni, Elena, Bandini, Giuseppe, Pezzi, Annalisa, Tacchetti, Paola, Rizzello, Ilaria, Pantani, Lucia, Arpinati, Mario, Zannetti, Beatrice A, Rocchi, Serena, Sessa, Mariarosaria, Brioli, Annamaria, Mancuso, Katia, Terragna, Carolina, Testoni, Nicoletta, Bonifazi, Francesca, Cavo, Michele
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V126.23.1968.1968

▪ Allogeneic stem cell transplantation (allo-SCT), which provides a tumor-free graft, is an alternative approach to autologous transplantation for multiple myeloma (MM) that offers the possibility of cure through a graft vs myeloma effect (GVM). However, the inherent non relapse mortality (NRM) and the high post-transplant relapse rate are the major shortcomings of this strategy which continues to have a controversial role in MM treatment. To highlight the long-term clinical outcomes of allo-SCT, we performed a retrospective analysis on 102 patients (pts) with MM who received at our Institution either a myeloablative (MA) (74 pts) or a non-myeloablative (NMA) (28 pts) conditioning regimen between 1990 and 2014. The MA regimen consisted in low dose TBI and cyclophosphamide (cyclo) ± melphalan (mel) or busulfan-cyclo. The NMA regimen was mel-fludarabine. Graft versus host disease (GVHD) prophylaxis consisted in cyclosporine + methotrexate (83%) or mycophenolate (17%), with the addition of thymoglobulin for unrelated or related female vs male recipient donors. The median age was 42 yrs (IQR 38-47), 60% pts were male. The hematopoietic cell donors were sibling in 77 pts and unrelated in 25, while the source of stem cells was peripheral blood in 65 and bone marrow in 37 pts. Fifty-six pts received allo-SCT as first-line therapy, 31 as second-line and 13 as third or fourth-line. Median time from diagnosis to allo-SCT was 22 months. Response status at the time of transplant was at least PR in 63% of the pts, including ≥ VGPR in 36% and CR in 12%. Overall, the response rate after allo-SCT was as follows: CR 58%, VGPR 19%, PR 18%. Median CR duration was 10 years (44% at 15 years). The incidence of acute grade II-IV and III-IV GVHD was 25% and 15%, respectively. The incidence of all grades chronic cGVHD was 48%, grade ≥2: 24%, with a median onset time of 178 days. By competitive risks analysis, the cumulative incidence of cGVHD at 1 and 3 years was 20% and 32%, respectively. On univariate analysis, the gender combination of female donor-male patient resulted in significantly higher incidence of cGVHD (sub hazard ratio, SHR, 2.3, P= 0.03). The cumulative incidence of NRM was 6.6% at 100 days, 11% at 1 year and 14.4% at 3 years, with lack of statistically significant relationship with the conditioning regimen. By univariate analysis, < PR prior to allo-SCT (SHR 2.8) and all grades cGVHD (SHR 4.6) were significantly associated with an increased NRM. By competitive risk