ALBERT

Beschreibung: Acute GVHD is a major cause of morbidity and mortality following NST. A high incidence of aGVHD occurs when CSA alone is used as prophylaxis. We investigated the effect of combining either mycophenolate mofetil (MMF) or an abbreviated course of low dose MTX with CSA on the incidence and severity of aGVHD. Between 11/97 and 07/07, 230 consecutive patients (pts) (solid tumors n=127, hematologic malignancies n=57, non-malignant hematologic disorders n=46) underwent conditioning with fludarabine (125mg/m2) and cyclophosphamide (120mg/kg), followed by a G-CSF mobilized PBSC transplant from an HLA identical (n=222: 96%) or 5/6 HLA-matched (n=8: 4%) related donor. Forty-eight pts with a history of heavy RBC transfusions or those receiving a 5/6 HLA-matched transplant had ATG (40mg/kg/d × 4 days) added to their conditioning. The initial cohort of pts (Group 1, n=66), received CSA alone (dose adjusted to maintain therapeutic serum levels) as GVHD prophylaxis. Due to the high incidence of severe aGVHD in this group, subsequent pts received CSA with either MMF (1 gram po bid; Group 2, n=82) or an abbreviated course of mini-dose MTX (5mg/m2 days +1, +3, +6; Group 3, n=82). In all three groups, decisions regarding discontinuation of CSA and MMF were based on donor T cell chimerism, presence of GVHD, and disease status. With a median follow-up of 2963, 2317 and 894 days in the three consecutive cohorts, a comparison was undertaken using competing risk analysis. The incidence of grades II–IV and III–IV GVHD was significantly higher in pts receiving CSA alone or CSA+MMF compared to those receiving CSA+MTX; the cumulative incidence of grades II–IV GVHD in the three groups was 56%, 59%, and 37% (p=0.05) while grades III–IV GVHD occurred in 30%, 34%, and 15% (p=0.019) respectively. The incidence of chronic GVHD (45% vs. 57% vs. 46%, p=0.27) was similar in the three groups. The lower incidence of aGVHD associated with MTX use was accompanied by a significantly improved TRM in group 3 pts; transplant related mortality was 21% in group 1, 21% in group 2 and 5% in group 3 pts (p=0.019). The impact of adding MMF or MTX to CSA on disease-specific outcome in pts with different malignant diseases could not be assessed due to small sample sizes. Conclusion: The addition of an abbreviated course of mini-dose methotrexate to CSA was associated with a significantly lower incidence of grades II–IV and III–IV aGVHD as well as lower TRM compared with CSA used alone or in combination with MMF in pts undergoing NST. To our knowledge this is the first report demonstrating a benefit of adding mini-dose MTX for GVHD prophylaxis in patients undergoing NST. Group 1 (N=66) Group 2 (N=82) Group 3 (N=82) P value Cumulative Incidence of Grade II–IV aGVHD (95% CI) 56% (44%–68%) 59%(48%–70%) 37%(25%–49%) 0.05 Cumulative Incidence of Grade III–IV aGVHD (95% CI) 30%(19%–41%) 34%(22%–46%) 15%(7%–23%) 0.019 Transplant Related Mortality(95% CI) 21%(11%–31%) 21%(12%–30%) 5%(0%–7%) 0.019 Proportion of Evaluable Pts with Chronic GVHD (%) 24/53 (45%) 43/75(57%) 34/74(46%) 0.274

Beschreibung: Previous studies have shown that granulocyte colony stimulating factor (G-CSF) mobilization skews T-cells toward a type 2 cytokine profile, potentially impacting GVHD and other immune mediated events that occur after allogeneic hematopoietic stem cell transplantation (HCT). AMD3100, a selective antagonist of CXCR4, rapidly mobilizes hematopoietic progenitor cells into the circulation, has a synergistic effect on CD34+ cell mobilization when combined with G-CSF, and is currently being evaluated as a single agent to mobilize allografts. Apheresis collections mobilized with a single injection of AMD3100 contain a similar number of T-cells as those collected following 5 daily doses of G-CSF. We investigated whether T-cells mobilized with AMD3100 undergo changes in cytokine polarization status as described to occur with G-CSF mobilization. Using real time PCR, we investigated the expression of 84 genes associated with TH1, TH2, and TH3 T-cell pathways at baseline and following mobilization with a single injection of AMD3100 (dosed at 240 or 320 mcg/kg; n=12 subjects) or following 5 daily doses of G-CSF(n=5 subjects). RNA was extracted from CD3+ T-cells isolated using immunomagnetic beads (〉95% purity) from PBMCs collected immediately before mobilization and 6 hours after AMD3100 administration or 5 days after G-CSF mobilization. The RT2 Profiler ™ PCR Array was used which contains pathway specific cytokine genes associated with TH1, TH2, and TH3 cells. Expression levels of 16 genes changed significantly (false discovery rate=0.10) from baseline following G-CSF mobilization; 9 genes were up-regulated and 7 genes were down-regulated from baseline. Five up-regulated and 4 down-regulated genes had greater than a 2-fold change in expression (Figure). In contrast, none of the 84 genes examined, including the 16 altered with G-CSF, changed significantly following AMD3100 administration. Our results are concordant with current literature that shows the expression of several genes effecting T-cell cytokine polarization are altered in G-CSF mobilized T-cells. It has been suggested that the TH2 polarization in G-CSF mobilized products contributes to the comparable incidence of acute GVHD and the higher incidence of chronic GVHD compared to bone marrow allografts. In contrast, T-cells mobilized with AMD3100 appear similar to non-mobilized T-cells, and do not undergo a change in TH1- and TH2-related gene expression. Whether the differences in cytokine polarization of T-lymphocytes mobilized with AMD3100 compared to G-CSF will impact immune reconstitution or other immune sequela (i.e. GVHD, graft-vs.-tumor) associated with HCT is currently being assessed in a pilot allogeneic transplantation trial in humans using AMD3100 to mobilize donors. Figure: Heat map showing expression levels of 16 genes in CD3+ T-cells that changed significantly from baseline following G-CSF mobilization in 5 healthy donors. Samples were analyzed with a two-sample paired t-test, and the corresponding p-values were evaluated based on the permutation technique at a 10% false discovery rate. All samples were normalized to the center of the mean of the pre G-CSF samples with black denoting up-regulated expression and white denoting down-regulated expression. Figure:. Heat map showing expression levels of 16 genes in CD3+ T-cells that changed significantly from baseline following G-CSF mobilization in 5 healthy donors. Samples were analyzed with a two-sample paired t-test, and the corresponding p-values were evaluated based on the permutation technique at a 10% false discovery rate. All samples were normalized to the center of the mean of the pre G-CSF samples with black denoting up-regulated expression and white denoting down-regulated expression.

Beschreibung: Background: AMD3100 (AMD or plerixafor) inhibits the binding of SDF-1 to its cognate receptor CXCR4 resulting in the rapid mobilization of CD34+ hematopoietic progenitor cells into the peripheral circulation. A prior phase I study suggested peak CD34+ cell mobilization occurred 6–8 hours following a 240 mcg/kg dose of AMD. This investigation provides preliminary data on the safety and CD34+ cell mobilizing effects of doses up to 480 mcg/kg of AMD. Methods: To account for inter-subject variability, subjects in three cohorts received two different subcutaneous doses of AMD. Healthy volunteers received the following doses of AMD: 240 mcg/kg and 320 mcg/kg (cohort 1); 320 mcg/kg and 400 mcg/kg (cohort 2); and 400 mcg/kg and 480 mcg/kg (cohort 3). Subjects received the higher dose at least 14 days after the first to allow adequate wash-out of AMD. The absolute number of circulating CD34+ cells were measured after each dose at the following times: 0, 2, 4, 6, 8, 10, 12, 14, 18, and 24 hours. In addition, this study assessed the following parameters: adverse events, AMD pharmacokinetics (400 and 480 mcg/kg doses), cytokine polarization status (Th1 vs Th2) of AMD mobilized CD3+ T-cells, and endothelial progenitor cell measurements. Results: To date, 16 of the planned 18 subjects have been enrolled on study with final results available for the first two cohorts; preliminary results exist for four subjects in the third cohort (400 mcg/kg vs 480 mcg/kg dose). Common toxicities include diarrhea, nausea, sinus tachycardia, injection site redness, perioral paresthesias, and headache. No dose limiting toxicities were observed; however, the frequency and/or magnitude of headache, nausea, vomiting, diarrhea, and tachycardia were greater at the 400 mcg/kg dose. Table 1 summarizes the preliminary CD34+ mobilization results for the 240, 320, and 400 mcg/kg doses. The lines in figures 1 and 2 show the difference in an individual subjects peak CD34+ cell number mobilized following 2 different doses of AMD. Conclusion: Although this phase I study is ongoing, preliminary data suggest doses of AMD higher than 240 mcg/kg may improve the peak numbers of CD34+ cells mobilized into the circulation. Furthermore, although dose escalation continues, the adverse events observed after a 400 mcg/kg dose of AMD appear similar to those observed after lower doses; no grade 3 or 4 adverse events have been observed. The final study results will provide additional data on the dose of AMD that optimizes CD34+ cell and CFU-GM mobilization for both autologous and allogeneic hematopoietic stem cell collections. CD 34+ cell mobilization 240 mcg/kg 320 mcg/kg 400 mcg/kg *Two subjects in 400 mcg dose group had the same peak mobilization time at two time points: these were averaged Number of subjects 6 12 10 Mean mobilized CD34 cells/microliter 27 29 31 Standard deviation of CD34 cells/microliter 13 14 13 Average peak mobilization time in hours* 9 10 11 Range of peak mobilization times in hours 8−14 6−14 8−18 Figure Figure