Comparison of outcomes at two institutions of patients with ALL receiving ex vivo T-cell-depleted or unmodified allografts

We compared outcomes of adult patients receiving T-cell-depleted (TCD) hematopoietic SCT (HCT) without additional GVHD prophylaxis at Memorial Sloan Kettering Cancer Center (MSKCC, N=52), with those of patients receiving conventional grafts at MD Anderson Cancer Center (MDACC, N=115) for ALL in CR1 or CR2. Patients received myeloablative conditioning. Thirty-nine patients received anti-thymocyte globulin at MSKCC and 29 at MDACC. Cumulative incidence of grades 2-4 acute (P=0.001, 17.3% vs 42.6% at 100 days) and chronic GVHD (P=0.006, 13.5% vs 33.4% at 3 years) were significantly lower in the TCD group. The non-relapse mortality at day 100, 1 and 3 years was 15.4, 25.0 and 35.9% in the TCD group and 9.6, 23.6 and 28.6% in the unmodified group (P=0.368). There was no difference in relapse (P=0.107, 21.3% vs 35.5% at 3 years), OS (P=0.854, 42.6% vs 43.0% at 3 years) or RFS (P=0.653, 42.8% vs 35.9% at 3 years). In an adjusted model, age >50, cytogenetics and CR status were associated with inferior RFS (hazard ratio (HR)=2.16, P=0.003, HR=1.77, P=0.022, HR=2.47, P<0.001), whereas graft type was NS (HR=0.90, P=0.635). OS and RFS rates are similar in patients undergoing TCD or conventional HCT, but TCD effectively reduces the rate of GVHD.