Effect of T Cell Recovery on Overall Survival (OS) Following Pentostatin Conditioning for Nonmyeloablative Allogeneic Stem Cell Transplantation (NST)

Autor: James E. Talmadge, Sarah Maas, Ziviko S. Pavletic, Laura R. Schafer, Orhan Turken, Robert G. Bociek, Lori Zobel, Marcel P. Devetten, Ugur Coskun, Charles A. Kuszynski
Rok vydání: 2007
Předmět:
Zdroj: Blood. 110:2994-2994
ISSN: 1528-0020
0006-4971
DOI: 10.1182/blood.v110.11.2994.2994
Popis: NST provides graft-versus-leukemia (GVL) activity with reduced regimen related toxicity. We used a conditioning regimen consisting of Pentostatin 4 mg/m2 daily × 3 days and 200 cGy TBI 24 hrs prior to stem cell infusion in patients (pts) with high-risk/relapsed/refractory hematologic malignancies. The importance of the timing of stem cell infusion relative to Pentostatin administration was examined in a comparison of two sequential protocols. In cohort 1 (n=39) Pentostatin was given on days -21, -20, and -19. In cohort 2 (n=39) Pentostatin was given on days -10, -9, and -8. The median age of the day -21 cohort was 52 years (range 22–70) and the day -10 cohort was 59.5 years (range 36–70). The median number of prior therapies in the day -21 cohort was 4 (range 0–8), including prior autologous SCT in 22 pts, while in the day -10 cohort, the median number of prior therapies was 6 (range 0–18), including prior autologous SCT in 9 pts. Post-grafting immunosuppression was cyclosporine (CsA)/mycophenolate mofetil (MMF). In both protocols, CsA 2.0 mg/kg IV q12 hrs was administered on days -1, 0, and +1, and then converted to oral 5 mg/kg PO BID with a taper beginning on day +70. In the second protocol, pts with unrelated donor transplants tapered CsA starting at day +100. MMF at 15 mg/kg PO BID was administered on days 0–27 for related donor transplants in both protocols and in the second protocol this was extended until day +40 for the unrelated donor transplants. In the day -21 protocol, SCTs were obtained from matched related (n=14) or unrelated (n=25) donors. The cumulative incidence of all grades of acute GVHD at day 100 was 40% and was more common in unrelated donor (60%) vs. related donors (15%) transplants. In the day -10 protocol, SCT was performed with products from matched related (n=15) or unrelated (n=21) donors. The cumulative incidence of grade II–IV acute GVHD was approximately 35% (30% in related versus 40% in unrelated donors). In both protocols, the median chimerism values for CD3+ cells and white blood cells at day 28 were >80% and 90% donor cells, respectively. T, B and natural killer (NK) lymphocyte frequency and numbers were identical at protocol entry. One day following TBI conditioning, there was a 57% depression in CD3+ cells in the day -21 protocol that was retained on day 28 post transplant (55%). In the day -10 protocol, there was a significant depression (47%) in the frequency of CD3+ cells one day following TBI, which was depressed further (68%) on day 28 post transplant. The dendritic cells (DCs), both CD123+ and CD11c+, were not suppressed by the conditioning regimen. Separation of pts on day 28 into cohorts with an absolute number of CD3+ cells >0.25×106/ml revealed that those pts with a higher CD3+ cell count had a median OS time of 36.7 weeks, which was significantly longer than pts whose absolute number of CD3+ cells
Databáze: OpenAIRE
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