EBMT Risk Score for Pre Transplant Risk Assessment in Patients with Multiple Myeloma.

Allogeneic hematopoietic stem cell transplantation (allo-HCT) is a potentially curative treatment for patients with multiple myeloma (MM) but its use is limited by high non-relapse mortality (NRM). European Group for Bone Marrow transplant (EBMT) risk score is a validated predictor of outcome for patients undergoing allo-HCT for hematological malignancies. It takes into consideration patient's age, donor's gender and type, disease status and the interval from diagnosis to allo-HCT, with the score ranging from 0 to 7. We assessed the impact of EBMT risk score in MM patients undergoing allo-HCT.

A total of 189 patients with MM who underwent HSCT between November 1985 and June 2010 at MD Anderson Cancer Center were included in the analysis.

Patient characteristics are summarized in Table 1. There were 110 males (58%) and 79 females (42%) with a mean age of 50 years (range 28–70). Donors were related in 146 patients (HLA-identical=131, 1 antigen mismatched (AGMM) = 5, 2 AGMM =1, 3AGMM=1, syngeneic=8) and unrelated in 43 patients (HLA identical= 37, 1AGMM=4, 2AGMM=1, unknown=1). One-hundred and twelve patients had prior autologous transplants (auto-HCT). Of these 83 had 1, 28 had 2 and 1 had 3 prior auto-HCT, respectively. Median time from diagnosis to allo-HCT was 24.7 months (range 3.3–232) and median overall follow up was 13 months (0.2–266). Overall 94 patients (49%) had progressed before last follow-up. Incidence of all-cause mortality was 138 (73.4%) with 69 (36%) of all deaths attributed to NRM. KM estimates of 2-year PFS and OS were 25% and 42%, and 5-year PFS and OS were 16% and 27%, respectively. Cumulative incidence (CI) of grade 2–4 and grade 3–4 acute graft versus host disease (aGVHD) was 33% and 13%, respectively. Cumulative incidence of overall and extensive chronic GVHD (cGVHD) was 47% and 17%, respectively. EBMT risk score was, 0–3 for 41 (21.7%), 4 for 72 (38.1%) 4 and 5–7 for 76 (40.2%) patients. EBMT risk score was higher for males, African-Americans and older allo-HCT recipients, patients with higher LDH levels (>618mg/dl), ß2-microglobulin >3.5mg/dl and patients with bone marrow plasmacytosis. Median PFS in patients with EBMT scores 0–3, 4 and 5–7 were 10.1, 8.4 and 6.4 months, respectively (P=0.0036). Median OS in patients with EBMT scores 0–3, 4 and 5–7 were 39, 15.8 and 9.6 months, respectively (p=0.001). Cumulative NRM in patients with EBMT scores 0–3, 4 and 5–7 were 37% (15/41), 36.1% (26/72) and 37.3% (28/75), respectively (p= 0.234). Cumulative incidence of progression in patients with EBMT scores 0–3, 4 and 5–7 were 36.5% (15/41), 50% (36/72) and 56.5% (43/76), p=0.119. Compared to those with EBMT risk score (0–3), individuals with EBMT risk scores >5 had a higher risk of all-cause mortality (HR 2.34, 95% CI 1.44–3.80), and disease progression (HR 3.06, 95% CI 1.67–5.61). Addition of ß2-microglobulin, BM plasma cells or prior response status alone or in combination with EBMT risk score significantly improved the discrimination properties of the model containing EBMT score alone (p<0.05).

EBMT risk score is an independent predictor of survival in MM patients undergoing allo-HCT. Addition of myeloma-specific factors predictors (ß2-microglobulin, plasma cell infiltration and prior response status) to EBMT score significantly improves its prognostic impact.

Giralt:Millenium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding.