ALBERT

Description: The risk of developing post transplant lymphoproliferative disease (PTLD) following solid organ transplantation (SOT) in children is in large part dependent on the specific organ transplanted and the degree of immune suppression post SOT (Webber et al Lancet 2006; Dharnidharka et al Transplantation 2001; Newell et al Transplantation 1996). However, the importance of expression of CD20 and/or Epstein-Barr virus (EBV) as prognostic factors for development and survival of pediatric PTLD after SOT in young patients are poorly understood. We previously demonstrated the safety and efficacy of cyclophosphamide, prednisone and rituximab (CPR) in CD20+ PTLD (Orjuela/Cairo, CCR 2005). We now report on our experience in children, adolescents and young adults with PTLD following SOT treated at a single institution from 1990–2008 and on the prognostic significance of expression of CD20 and EBV in this population. 45 SOT pts (28 heart, 11 liver, 6 kidney) were diagnosed with PTLD (53.3 % female) at a mean onset of 45±43 months (mo) post primary SOT (4–153). Three patients had multiple SOT. Age at diagnosis of PTLD ranged from14 to 287 mo with mean 118 (SD=77) mo. EBV and CD20 status were evaluated in all evaluable tumor sites. CD20 status was categorized as positive when all tumor sites expressed CD20 (by IHC) and negative when only some or no tumor sites expressed CD20. EBV status was categorized as positive when any tumor sites were EBV positive (by ISH), and negative when no tumor sites were EBV positive. Of 40 evaluable tumors (11 monomorphic, 19 polymorphic, 5 early lesions, 2 T-cell lymphomas, and 3 rarer types (2 HD, 1 multiple myeloma like), 32 (80%) had detectable EBV, while 28 (70%) were classified as CD20 positive. EBV expression was unrelated to age at SOT. Those patients whose PTLD expressed CD20 and/or EBV had shorter time interval between last SOT and the onset of PTLD (CD20 positive vs negative (mean±SD): 28±31 mo vs 64±44 mo, p

Description: Abstract 2069 Over the past decade there has been a shift in treating pediatric patients with RTC followed by allogeneic stem cell transplantation (alloSCT) for malignant and non-malignant diseases (Satwani/Cairo et al, BBMT 2005). Advantages of RTC over MAC include reduced acute short- and long-term late complications, reduced risk of infections, and improved survival. However, relatively little is known about the impact of RTC on the longitudinal quality of life (QOL) of these patients following alloSCT. The objective of this study was to compare the physical, emotional, and social functioning of children who received RTC versus MAC regimens prior to and after alloSCT. Hierarchical linear modeling (HLM) was used to explore trends in the PedsQL 4.0 physical, emotional, and social functioning and select individual items of 80 children ≥ 5 years of age undergoing alloSCT between Nov. 2002 and Dec. 2008. QOL was assessed once pre-alloSCT and on days 100, 180, 365, and 730, post-alloSCT. In addition, post hoc exploratory analyses were performed to further evaluate the effect of RTC and MAC regimens on QOL outcomes. If significant between- or within-group differences were observed for any of the three sub-scales, HLM procedures were performed for each sub-scale item to identify the item(s) affected by treatment. Since post hoc analyses were exploratory no adjustments were made in the alpha level. This secondary data analysis was not powered to detect statistically significant differences. Effect size (ES) calculations were included to describe the magnitude of change in scores from baseline and were calculated using the within patient standard deviation (SD), whereas the magnitude of the difference in scores between RTC and MAC regimens were calculated using the between group SD and interpreted according to Cohen's thresholds. Mean age: 12.67 years; malignant/non-malignant 59%/41%; RTC/MAC 54%/46%. There was no significant difference (p = 0.87) between the baseline mean emotional functioning scores of patients treated with RTC (M = 75.90) or MAC (M = 75.30). In addition, there was no appreciable difference (p = 0.08) in the slope function between these two groups. Similarly, the baseline mean social functioning scores did not differ (p = 0.51) between groups with the RTC patients (M = 81.62) having equivalent function to MAC patients (M = 83.73). Furthermore, the rate of change over time between the two groups was not significantly different (p = 0.96). However, a significant change from baseline in overall physical functioning was estimated for RTC (M = 66.84) compared to MAC (M = 68.05) with RTC improving at a rate of 0.48 points per month (ppm)/ 5.82 points per year (ppy) and MAC improving by 0.04ppm/ 0.52ppy (t = 2.34; p = 0.02) (Figure 1). At 2-years post-alloSCT a moderate difference was estimated (ES = 0.71 SD) with RTC scoring 9.35 points higher than MAC. Post hoc analyses of physical functioning items revealed baseline impairments in lifting something heavy for both RTC (M = 55.55) and MAC (M = 56.06). However, the RTC group rapidly improved by 7.12ppm (t = 2.07; p = 0.03) with no lifting problems estimated by 6-months post-alloSCT. MAC improved by 1.27ppm, with some lifting difficulties predicted throughout the follow-up period. A large effect size difference in lifting scores was estimated at 2-years post-alloSCT with MAC scoring 6.74 SD lower than RTC. Greater improvements in fatigue scores were predicted for RTC (M = 60.11; 3.39ppm) compared with MAC (M = 65.19; 2.46ppm) (p 〉 0.05) with no fatigue estimated by 1-year post-alloSCT for both groups. RTC pain scores improved from baseline by 2.82ppm (M = 66.02) and 5.35ppm for MAC (M = 66.95). No difficulties with pain were estimated by 1-year for RTC and by 6-months for MAC. Emotional and social functioning were not influenced by the intensity of conditioning regimen received. Deficits in physical functioning appeared transient with most perturbations expressed in the acute post-alloSCT period. RTC versus MAC prior to AlloSCT in pediatric recipients was associated with significantly fewer deficits and faster recovery in overall physical functioning, strength, and fatigue. This study highlights the importance of including QOL as part of the treatment investigations to further define outcomes that are related to the intensity of conditioning regimens used in pediatric alloSCT.Figure 1:Estimated change in physical functioning between RTC vs. MAC in pediatric alloSCT recipientsFigure 1:. Estimated change in physical functioning between RTC vs. MAC in pediatric alloSCT recipients Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 3504 The only known curative therapy for patients with SCD is a matched family donor AlloSCT (Walters et al, NEJM, 1996). Complications after myeloablative AlloSCT are numerous and include death, graft versus host disease (GVHD), and infections, making reduced toxicity conditioning regimens more appealing. A major obstacle allowing most SCD patients to undergo SCT is the lack of an unaffected, HLA-matched identical sibling (Bhatia et al, BMT, 2008). Umbilical cord blood (UCB) has been proven to be an excellent alternate donor source that can safely reconstitute hematopoiesis after AlloSCT in pediatric recipients with non-malignant conditions (Cairo et al, BBMT, 2008). In this study, we report the results of a RTC regimen followed by an AlloSCT from matched family and unrelated UCB donors in selected patients with symptomatic SCD. Between August 27, 2004 and March 2, 2010, 18 patients (14M:2F) with symptomatic SCD (HbSS=10, HbSC=4, HbSßThal=4) underwent an AlloSCT. Indications for SCT included: ACS (n=8), CVA (n=2), multiple VOC (n=9), splenic sequestration (n=6) and retinopathy (n=1). Conditioning was Bu (4mg/kg × 4d 〈 4 yrs and 12.8mg/kg × 4d 〉 4 yrs), Flu (30mg/m2 × 6d), and Alemtuzumab (2mg/m2 × 1d, 6mg/m2 × 2d, and 20mg/m2 × 2d). Median age was 6.29 yrs(1.3–19.2). Median follow-up was 26 months. Donor sources: 8-6/6 HLA-matched sibling bone marrow (BM), 2–6/6 sibling UCB, 1–6/6, 4–5/6 and 3–4/6 unrelated UCB. Donors were HbAA (n=13), HbAC (n=1), HbAS(n=3), or ßThal trait (n=1). Sibling BM recipients received a median total nucleated cell (TNC) dose/kg of 7.16 × 108 (range 2.27–11.31) and a median CD34 cell dose/kg of 5.38 × 106 (range 1.50–6.83). Recipients of related or unrelated UCB received a median TNC dose/kg of 4.35 × 107 (range 3.40–9.10) and a median CD34 cell dose/kg of 2.21 × 105 (range 0.60–7.94). All received tacrolimus and mycophenolate mofetil as GVHD prophylaxis (Bhatia/Cairo et al, BBMT, 2009) and phenytoin or keppra as seizure prophylaxis for 180 days post SCT. Patients receiving sibling donor AlloSCT had a median time to neutrophil engraftment of 16 days (range 13–41). Among evaluable unrelated UCBT recipients, median time to neutrophil engraftment was 34 days (range 27–47). Four patients (all unrelated UCBT) experienced primary graft failure at day +60 post-SCT secondary to CMV (n=2), adenovirus, and low Bu Css levels with early withdrawal of MMF. Patients with sibling donors had a median time to platelet engraftment of 26 days (range 17–75). Of evaluable unrelated UCB recipients, median time to platelet engraftment was 54 days (range 43–70). Patients achieved mean whole blood donor chimerism of 71.0, 79.6, 85.7, 92.9, 90.7% and 93.2% at days 30, 60, 100, 180, 365 and 730 post-transplant, respectively. Mean erythroid (CD71) donor chimerism at these time points was 78.1, 81.1, 86.6, 90.5, 87.9% and 94.0%, respectively. Patients with non-sickle cell trait donors had median HbS levels of 0% at 1 yr (n=8) and 2 yrs (n=3) post-SCT; those with sickle cell trait donors had median HbS levels of 38.3% at 1 yr (n=3) and 39% at 2yrs (n=3) post-SCT. Among evaluable patients, the Kaplan-Meier probability of grade II-IV acute GVHD is 33.3% and of chronic GVHD is 8.3%. Among the ten donor-recipient pairs in which at least one member of the pair had CMV positivity, four experienced CMV reactivation on days +13, +26, +30 and +32 (BM: n=2, unrelated UCB: n=2). Of the four patients with primary graft failure (all unrelated UCBT recipients), one resumed chronic transfusions, two died of complications from disseminated CMV and adenoviral infections, and one received a second myeloablative SCT 1 yr after initial SCT and died of fungal sepsis. Among all patients, the Kaplan-Meier probability of OS is 81.8% (100% with sibling donors, 62.5% with UCB donors) and of EFS is 77.8% (100% with sibling donors, 50% with UCB donors) with none of these patients showing any evidence of SCD symptomatology post-SCT. The longest follow-up is 2134 days. In summary, we report the largest experience of RTC and matched family AlloSCT in selected children with symptomatic SCD with persistent long-term donor chimerism and absence of SCD symptoms or progression of disease. However, with the high incidence of viral infections and toxic deaths following unrelated UCBT, it is too premature to extend this treatment option to those SCD patients lacking a sibling donor. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 36 Introduction: Despite dramatic improvements in cure rates for pediatric ALL and AML, the prognosis remains poor for pediatric patients with ALL or AML in third complete remission (CR3) or with relapsed or refractory disease (10-20% EFS). Single-agent clofarabine has demonstrated activity in CAYA with relapsed or refractory ALL and AML (Jeha et al., Blood, 2004, JCO, 2006 and JCO, 2009). Clofarabine is a potent inhibitor of DNA polymerase and ribonucleotide reductase; biochemical and clinical studies suggest synergy with cytarabine (Faderl et al., Blood 2005). Clofarabine in combination with cytarabine has been studied in adults with AML and MDS and results in greater rates of CR than clofarabine alone (Faderl et al., Blood, 2006 and Blood, 2008). The combination of clofarabine and cytarabine in CAYA with relapsed acute leukemia appears to be safe and well-tolerated (Cooper et al., ASH, 2009). Objectives: To determine the maximum tolerated dose (MTD) of clofarabine in combination with cytarabine and TBI followed by AlloSCT and to assess the safety, progression-free survival (PFS) and overall survival (OS) associated with this regimen in CAYA with poor-risk acute leukemia. Methods: We instituted a multi-center phase I/II study of a novel conditioning regimen consisting of clofarabine, cytarabine and TBI prior to AlloSCT in CAYA with ALL or AML in CR3, relapse, or induction failure (IF). Herein we report results from the phase I portion of the study. Eligible patients received 5 days (day-9 to day-5) of clofarabine (dose escalation with 40 mg/m2 [n=3], 46 mg/m2 [n=3], 52 mg/m2 [n=6]) and sequential cytarabine 1000 mg/m2 (day-10 to day-5) and TBI (1200cGy) followed by AlloSCT from matched related or unrelated donors. Unrelated donor AlloSCT recipients also received R-ATG 2 mg/kg (day-4 to -2). GVHD prophylaxis consisted of tacrolimus and MMF as we have recently described (Bhatia/Cairo et al., BBMT, 2009). Probabilities of engraftment, acute and chronic GVHD, PFS and OS were computed using the Kaplan-Meier method. Results: Twelve patients enrolled, median age 11 years (range 5–18), 10/2 M/F, 9 ALL (6 CR3, 2 refractory relapse, 1 CR2 with history of IF), 3 AML (2 primary IF, 1 treatment-related AML in CR3), 6 with history of IF, 6 related donors (5 bone marrow [BM], 1 PBSCs), 6 unrelated donors (3 BM, 2 umbilical cord blood [UCB], 1 PBSCs). HLA matching was 5/6 (n=4) or 6/6 (n=4) at HLA-A, B and DRB1 for related donors and unrelated UCB donors and 9/10 (n=1) or 10/10 (n=3) at HLA-A, B, C, DRB1 and DQB1 for unrelated BM or PBSC donors. Median total nucleated cell dose (TNC) was 4.76×108/kg (2.30-14.56) and CD34 dose 5.04×106/kg (2.41-10.10) for patients receiving BM or PBSCs and 4.78×107/kg (4.00-5.55) and 4.04×105/kg (1.41-6.66), respectively, for patients receiving UCB grafts. An MTD of clofarabine was not exceeded at 52mg/m2/dose. No serious adverse events related to clofarabine were observed. One patient developed grade III hearing loss in the setting of atypical PRES, unlikely related to clofarabine, with normal cochlear function and abnormal auditory brainstem response. All engrafted neutrophils at median day 14 (12-29) and 90% of evaluable patients engrafted platelets at median day 36 (16-97). All achieved 100% whole blood donor chimerism by day +30. Day 100 transplant related mortality is 0%. The probability of grade II-IV acute GVHD was 43% (CI95: 13–71%); no patients developed chronic GVHD. Two patients died days +137 and +182 from multi-organ failure in the setting of infection and acute GVHD. Two experienced progressive disease on days +87 and +126 and received further therapy off study; one remains alive and stable. Eight are alive in continuous CR at a median of 209 days (40-770). Probabilities of PFS and OS are 53.3% (CI95: 18–80%) and 61.0% (CI95: 20–86%), respectively. Conclusions: Myeloablative conditioning with clofarabine, cytarabine and TBI followed by AlloSCT from related or unrelated donors is well tolerated in CAYA with poor-risk ALL and AML. Clofarabine 52 mg/m2/day × 5 days in combination with cytarabine and TBI can safely be used in the phase II study. Preliminary results from the phase I cohort are encouraging with respect to the risk of early relapse, despite poor-risk underlying disease. Efficacy data and measurements of change in minimal residual disease in the phase II study will provide a broader experience at the MTD to assess the role of this conditioning regimen in CAYA with poor-risk acute leukemia. Disclosures: Talano: Genzyme: Membership on an entity's Board of Directors or advisory committees. Cairo:Genzyme: Research Funding, Speakers Bureau.

Description: Abstract 2304 Poster Board II-281 Introduction. Immune reconstitution in pediatric transplant recipients appears to take longer following myeloablative conditioning (MAC) and umbilical cord blood transplantation (UCBT) than following matched sibling allogeneic stem cell transplantation (AlloSCT) (Parkman et al., BBMT, 2006). Reduced toxicity conditioning (RTC) is associated with less transplant-related morbidity and mortality than MAC prior to AlloSCT although the effects of RTC on long-term immune reconstitution in UCBT recipients are unknown (Satwani, Cairo et al., BBMT, 2005). We previously demonstrated sustained donor chimerism following RTC and UCBT in pediatric recipients (Bradley, Cairo et al., BMT, 2007). Our group recently found no significant difference between MAC and RTC in time to engraftment or donor chimerism in pediatric UCBT recipients; RTC was associated with decreased transplant-related mortality (TRM) and improved overall survival (OS) (Cairo et al., ASBMT, 2009). Objective. We analyzed time to immune reconstitution and associated risk factors in pediatric patients receiving RTC vs. MAC prior to UCBT. Methods. We evaluated immune reconstitution in 88 consecutive pediatric UCBT recipients with transplant dates between March 2000 and October 2008. Absolute CD3, CD4, CD8, CD19, and CD56 cell counts and IgG, IgA, and IgM levels were assessed using FACS analysis and ELISA, respectively, at days 100, 180, and 365 post-transplant. Predictors of grade II-IV acute GVHD, lymphocyte recovery, and malignant recurrence were analyzed using chi-square or Fisher's exact tests and multivariable logistic regression models. Results. The median age of the 88 patients was 6.5 years (range 0.25-22); 59% male/41% female, 56% MAC/44% RTC, HLA match 19% 6/6, 28% 5/6, 52% 4/6, 93% unrelated/7% related, 66% malignant/34% non-malignant, median TNC x107/kg 3.76 (range 0.9-22.61), and median CD34 ×107/kg (range 0.34-9.57). Mean (±SD) absolute lymphocyte subset counts (cells/μL), immunoglobulin levels (mg/dL) and sample sizes at days 100, 180, and 365 post-transplant are shown in Tables 1 and 2, respectively. At day 180, NK cell levels were slightly higher in the MAC group (310.0±212 vs. 171.3±83, p=0.05). Otherwise, MAC and RTC did not differ with respect to absolute lymphocyte subset counts or immunoglobulin levels. Other variables not associated with T-, B- and NK-cell reconstitution include grade II-IV acute GVHD, ATG/Campath conditioning, viral/fungal infection, and TNC/CD34 dose/kg. Lymphocyte subset counts and immunoglobulin levels were assessed as being normal or low according to age-specific reference ranges and did not differ significantly between MAC and RTC groups. Of 88 subjects, 24 (27.3%) developed grade II-IV acute GVHD. In a logistic regression model that included conditioning regimen (MAC vs. RTC), risk (average vs. poor), HLA-matching (4/6 vs. 5-6/6), CMV status (donor/recipient -/- vs. other), and time period (before 2005 vs. after 2004) to analyze predictors of grade II-IV GVHD, MAC recipients had a significantly higher risk of grade II-IV acute GVHD (odds ratio 4.43, p=.01), and of viral infection (odds ratio 3.86, p=.02) than RTC recipients. Malignant relapse occurred in 12 of 34 MAC recipients (35%) and 11 of 24 RTC recipients (46%). Conclusions. No significant differences between lymphocyte subset counts or immunoglobulin levels post-transplant were found with respect to MAC vs. RTC prior to UCBT. Children who received RTC had a significantly lower risk of grade II-IV acute GVHD than children who received MAC, when other risk factors were taken into account. These results support the continued use of RTC prior to UCBT for appropriate medical conditions. Disclosures: Bradley: Bristol-Myers Squibb Company: Employment.