Heike Schieder

Pilot study of reduced-intensity conditioning followed by allogeneic stem cell transplantation from related and unrelated donors in patients with myelofibrosis

A prospective pilot study was performed to evaluate the effect of reduced‐intensity conditioning with busulphan (10 mg/kg), fludarabine (180 mg/qm) and anti‐thymocyte globulin followed by allogeneic stem cell transplantation from related (n = 8) and unrelated donors (n = 13) in 21 patients with myelofibrosis. The median age of the patients was 53 years (range, 32–63). No primary graft failure occurred. The median time until leucocyte (>1·0 × 109/l) and platelet (>20 × 109/l) engraftment was 16 (range, 11–26) and 23 d (range, 9–139) respectively. Complete donor chimaerism on day 100 was seen in 20 patients (95%). Acute graft‐versus‐host disease (GvHD) grades II–IV and III/IV occurred in 48% and 19% of cases and 55% of the patients had chronic GvHD. Treatment‐related mortality was 0% at day 100 and 16% [95% confidence interval (CI): 0–32%] at 1 year. Haematological response was seen in 100% and complete histopathological remission was observed in 75% of the patients and 25% of the patients showed partial histopathological remission with a continuing decline in the grade of fibrosis. After a median follow‐up of 22 months (range, 4–59), the 3‐year estimated overall and disease‐free survival was 84% (95% CI: 67–100%).

Comparable results in patients with acute lymphoblastic leukemia after related and unrelated stem cell transplantation

We report the results of 84 patients with ALL after related (n=46) or unrelated (n=38) allogeneic SCT. Mean recipient age was 23 years (range: 1–60) and median follow-up was 18 months (range: 1–133). Forty-three patients were transplanted in CR1; 25 in CR2 or CR3; four were primary refractory; four in PR; eight in relapse. The conditioning regimen consisted of TBI/VP16/CY (n=76), TBI/VP16 (n=2), TBI/CY (n=2), Bu/VP16/CY (n=4). The OS at 3 years was 45% (44% unrelated, 46% related). Univariate analysis showed a significantly better OS for patients <18 years (P=0.03), mismatched sex-combination (P=0.03), both with a stronger effect on increasing OS after unrelated SCT. Factors decreasing TRM were patient age <18 years (P=0.004), patient CMV-seronegativity (P=0.014), female recipient (P=0.04). There was no significant difference in TRM and the relapse rate was similar in both donor type groups. Multivariate analysis showed that factors for increased OS which remained significant were mismatched sex-combination (RR: 0.70,95% CI: 0.51–0.93, P=0.015), patient age < 18 years (RR: 0.66, 95% CI: 0.47–0.93, P=0.016). A decreased TRM was found for female patients (RR: 0.56, 95% CI: 0.33–0.98, P=0.042), negative CMV status of the patient (RR: 0.57, 95% CI: 0.36–0.90, P=0.015). Unrelated stem cell transplantation for high-risk ALL patients with no HLA-compatible family donor is justifiable.

Reduced-toxicity conditioning with treosulfan, fludarabine and ATG as preparative regimen for allogeneic stem cell transplantation (alloSCT) in elderly patients with secondary acute myeloid leukemia (sAML) or myelodysplastic syndrome (MDS)

We investigated a dose-reduced conditioning regimen consisting of treosulfan and fludarabine followed by allogeneic stem cell transplantation (SCT) in 26 patients with secondary AML or MDS. Twenty patients were transplanted from matched or mismatched unrelated donors and six from HLA-identical sibling donors. The median age of the patients was 60 years (range, 44–70). None of the patients was eligible for a standard myeloablative preparative regimen. No graft-failure was observed, and leukocyte and platelet engraftment were observed after a median of 16 and 17 days, respectively. Acute graft-versus-host disease (GvHD) grade II–IV was seen in 23% and severe grade III GvHD in 12% of the patients. No patients experienced grade IV acute GvHD. Chronic GvHD was noted in 36% of the patients, which was extensive disease in 18%. The 2-year cumulative incidence of relapse was 21%. The relapse rate was higher in patients beyond CR1 or with intermediate two or high risk MDS (P=0.02). The treatment-related mortality at day 100 was 28%. The 2-year estimated overall and disease-free survival was 36–34%, respectively. No difference in survival was seen between unrelated and related SCT.

Allogeneic stem-cell transplantation in patients with refractory acute leukemia: a long-term follow-up

We examined retrospectively 44 patients with refractory acute leukemia (acute myeloid leukemia (AML)/acute lymphoblastic leukemia=25/19) who underwent allogeneic transplantation at our center between 11/1990 and 04/2004. The median leukemic blasts was 25% and age 28 years (range, 3–56). Twenty-one patients had untreated relapse, 13 failed reinduction, eight in partial remission and two aplastic. Conditioning was myeloablative using cyclophosphamide, busulfan, total-body irradiation and etoposide (Bu/Cy/VP, n=22; TBI/Cy/VP, n=17; others, n=5) followed by marrow or peripheral blood transplant (n=23/21) from unrelated or related donors (n=28/16). All patients had graft-versus-host disease (GVHD) prophylaxis with cyclosporin and methotrexate. One patient experienced late graft failure. Severe acute-GVHD and chronic-GVHD appeared in eight and 14 patients, respectively. Thirteen patients (30%) remain alive after a median of 25.3 months (range, 2.4–134.1); with 31 deaths, mostly from relapse (n=15) and infections (n=12). Overall survival (OS) and progression-free survival (PFS) at 5 years was 28 and 26%, respectively. OS and PFS were significantly better with blasts ⩽20% and time to transplant ⩽1 year while transplant-related mortality was less with the use of TBI. We conclude that patients with refractory leukemia can benefit from allogeneic BMT, especially with ⩽20% marrow blast.

CD34+-selected stem cell boost for delayed or insufficient engraftment after allogeneic stem cell transplantation

BACKGROUND Poor graft function without rejection may occur after stem cell transplantation (SCT). CD34(+) stem cell boost (SCB) can restore marrow function but may induce or exacerbate GvHD. We therefore investigated the feasibility and efficacy of CD34(+)-selected SCB in some patients with poor graft function. We present the results for eight patients (median age 46 years) transplanted initially for myelofibrosis, acute leukemia, myeloma and NHL. Six patients had received HLA-matched and two mismatched grafts (PB, BM; n=5, 3). After a median of 128 days post-transplant, the median leukocyte and platelet counts were, respectively, 2.05/nL and 18/nL. None had achieved platelet counts >50/nL even though donor chimerism was >95% in seven recipients. METHODS Positive selection of CD34(+) stem cells was performed on a CliniMACS device, observing GMP and achieving a median of 98.5% purity. The patients received a median of 1.7 x 10(6)/kg CD34(+) cells and 2.5 x 10(3)/kg CD3(+) T lymphocytes. RESULTS Hemograms at days +30, +60 and +90, respectively, showed steadily increasing median leukocyte (2.55, 3.15 and 4.20/nL) and platelet (29, 39 and 95/nL) counts. After a median follow-up of 144 days, five patients remained alive. No patient had developed acute or chronic GvHD. One patient died of leukemic relapse and two others of systemic mycosis. DISCUSSION These preliminary results point to the possibility of safely improving graft function using CD34(+) positively selected stem cells without necessarily increasing the incidence of GvHD in patients with poor graft function post-SCT. Experience with more patients and longer follow-up should clarify the optimal role for this procedure.