DeCook, Lori

Abstract Introduction Myelofibrosis (MF), both primary myelofibrosis (PMF) and post essential thrombocytosis/polycythemia vera myelofibrosis (post ET/PV-MF), are chronic myeloproliferative neoplasms that are incurable with standard medical therapy. The only potential curative therapeutic modality remains allogeneic stem cell transplant (ASCT), but the optimum conditioning regimen has yet to be defined and may vary due to pre-ASCT factors such as age, donor source, and comorbidities. In the past, traditional myeloablative (MA) regimens have proven toxic. Reduced intensity conditioning (RIC) regimens have generally become the accepted standard of care for patients with PMF or Post PV/ET MF in need of ASCT, but with the potential for increase in relapse especially for high risk disease. The optimal conditioning regimen has yet to be defined. The regimen of Fludarabine, BCNU, and melphalan (FBM) is considered a reduced toxicity regimen that may afford the benefit of reduction in relapse without increase in toxicity and may “bridge the gap” between MA and RIC especially in older patients. Patients with MF have high inflammatory cytokine levels which may act as mediators of MF symptom burden and may further aggravate mediators of acute GVHD, which is one of the most frequent and severe complications of ASCT. Selection of conditioning regimen and GVHD prophylaxis are keys to MF transplant outcomes. We report here the results of 16 patients who received conditioning with FBM with rATG (FBM-A) with PMF and post PV/ET MF. Methods We conducted a retrospective review of all patients from October 2009 to November 2012 with PMF or post ET/PV-MF who underwent an ASCT with FBM-A. Patient demographic and transplant data were analyzed from a comprehensive database. The use of such data for reporting purpose was approved by the Mayo Clinic Arizona Institutional Review Board. Overall survival was estimated using Kaplan-Meier. Results There were 16 patients analyzed who had PMF or post PV/ET MF or overlap syndromes. The median follow-up of surviving patients is 20.4 months (range 8 months – 46 months). The median age was 60 (range 47-68 yrs) with 56% of patients being ≥ 60yrs. There were 8 males and 8 females. The JAK2 V617F mutation was present in 64% of patients. 86% were high risk according to the DIPSS system with 14% being intermediate-2 risk. None of the patients underwent splenectomy prior to transplant. The median HCT-CI score was 1.5 with 6 (38%) of the patients having an HCT-CMI ≥3. Donors were related in 10 patients (8 matched, 2 mismatched at 1 antigen) and unrelated in 6 (matched, n=3, 1-antigen mismatch, n=3). GVHD prophylaxis consisted of tacrolimus, MMF, and ATG 2.5 – 5.0 mg/kg. The cumulative incidence of acute GVHD grades III-IV was 15.3% at 6 months, and the cumulative incidence of NIH-defined moderate-to-severe chronic GVHD was 25% at 2 years. No patient has relapsed, and no patient has developed graft failure. There have been 4 deaths, 3 from GVHD, and 1 from infection. Among the 3 patients who died from GVHD, all were unrelated donor transplants, and 2 were mismatched unrelated transplants. The 2-year Kaplan-Meier estimate of overall survival (OS) is 72% (95% CI, 45 – 91%). The cumulative incidence of TRM was 12.6% (95% CI 3.9%-34%) at 1 year. Conclusion The reduced-toxicity regimen of FBM-A in PMF, Post ET/PV MF and overlap syndromes appear to provide the benefit of an ablative regimen with the tolerance of a RIC. The 2-year overall survival of 72% in our series is encouraging in an older population of predominantly high-risk patients. Treatment failure was related predominately to GVHD, which continues to be a significant obstacle to better long-term outcomes, especially in unrelated and mismatched patients. Reduced toxicity ASCT conditioning regimens in the setting of MF warrant further investigation. Disclosures: Reeder: Celgene: Research Funding; Novartis: Research Funding; Millenium: Research Funding.

Introduction Allogeneic hematopoietic stem cell transplant (HCT) patients are at risk for having a low Vitamin D (VD) level. VD level has been correlated with cancer incidence, pulmonary disease and infection. VD also has immunomodulatory properties and reports suggest that a low VD level increases the incidence of chronic GVHD and may impact mortality in HCT. HCT morbidity and mortality is attributed to infection, organ system toxicity, GVHD and recurrent disease. Identifying a correctable factor that would reduce the occurrence or severity of these complications would be beneficial. It is possible that VD may have significant effect on outcome after HCT due to its described properties. Normal VD level may infer better outcome for HCT patients by improving response in or preventing infection, protecting organ function, decreasing risk of relapse and/or decrease incidence or severity of GVHD. We hypothesize that there is a relationship between VD level and morbidity and mortality after HCT. We therefore studied VD levels pre- and post-HCT to determine if there was an impact of VD level on these outcomes. Patients and Methods Two hundred and fifty patients underwent myeloblative or non-myeloablative HCT between 3/12/2009 and 10/29/2012 at our institution. Baseline demographic data, disease characteristics, transplant variables and outcomes data were obtained from the transplant database. These data were supplemented by retrospective chart review for VD levels prior to transplant, at day 100 and 1 year post-HCT. Data were collected through day 100 for occurrence of infection and admissions to the ICU. Categories for VD level included normal (≥30 ng/ml) or abnormal (<30 ng/ml). Patient characteristics were compared using the Chi-square test or Wilcoxon rank sum test. The logrank test was used to compare the survival curves between groups, and the Cox proportional hazard model was used to measure the association between outcomes (mortality, relapse, acute or chronic GVHD) and VD level. Results Of the 250 patients undergoing HCT VD level was performed on 180 (72%) patients pre-HCT, 149 (60%) patients at day 100 post-HCT and 81 (32%) patients at 1 year post-HCT. The rate of acute or chronic GVHD was not significantly associated with VD level pre or post-HCT. Overall infection risk was not significant pre or post-HCT but when sorted by type of infection bacterial infection (p=0.01), radiologic evidence of pulmonary nodules/consolidation (p=0.03), and ICU admissions (p=0.0313) within the first 100 days post-transplant were significantly increased in patients who had a low VD level at day 100 post -HCT. Pre-HCT and 1 year post-HCT VD level did not impact mortality or relapse but there was a significant increase in one year mortality (p=0.02, HR = 5.99) and relapse (p = 0.03, HR=9.47) in patients who had a low VD level at day 100 post-HCT. Discussion This study shows that VD may play a significant role in bacterial infection, pulmonary infection, ICU admission, mortality and relapse after HCT. Those patients with a low VD level at day 100 post-HCT had significantly worse outcomes for relapse and mortality. Those patients with a low VD level at day 100 post-HCT had a higher incidence of lung infection, bacterial infection and admission to the ICU. In contrast to previous studies, we found no correlation between VD level and incidence of acute or chronic GVHD. This study is one of the largest reported and the first to our knowledge that reports decreased risk of certain types of infection (bacterial and lung), mortality and relapse in those with an adequate VD level receiving HCT. It is possible that supplementation of VD to keep levels ≥30 would reduce these complications of HCT. Future prospective study of VD is warranted. Finding a low cost and easy to administer therapy (such as VD replacement) that would reduce morbidity, mortality and relapse in the HCT population is needed. Disclosures: Reeder: Celgene: Research Funding; Novartis: Research Funding; Millenium: Research Funding.

Abstract Abstract 3040 We have previously shown that both lymphocyte and monocyte recovery are strongly associated with improved survival post-myeloablative allogeneic hematopoietic stem cell transplant for acute leukemia (Thoma et al, Biology of Blood and Marrow Transplantation, in press). We hypothesized that rapid lymphocyte and monocyte recovery would have a similarly positive impact on overall survival in reduced intensity conditioning (RIC) HSCT with fludarabine/melphalan. To test our hypothesis, we analyzed 118 consecutive patients who underwent allogeneic HSCT with fludarabine/melphalan conditioning for AML (n=49) and MDS/MPN (n=38), ALL (n=7) and other lymphoid malignancies (n=24) at our institution from 2001–2010. The absolute lymphocyte counts and monocyte counts (ALC and AMC, respectively) derived from routine complete blood counts were determined longitudinally at days +15, +30, +60, +100 and correlated with clinical outcomes. At the day +30 time point, both ALC and AMC > 0.3 × 10(9) cells/L were strongly associated with improved survival (OS 29.6 months vs. 5.4 months, p=0.006 and 25.3 months vs. 5.1 months, p=0.01 respectively), a pattern that continued through the day +100 evaluation. Multivariate analysis including age, CD34+ cell dose, unrelated vs. related HSCT, presence of aGVHD, remission status, and longitudinal hematologic parameters revealed that day +100 ALC (RR 0.21, 95% CI 0.07–0.66, p= 0.0096) and day +100 AMC (RR 0.41, 95% CI 0.2–0.9, p=0.047) were the only independent predictors of survival in the model. Pairwise correlations showed moderate negative associations between aGVHD and day +60 and day +100 ALC and AMC. To further explore whether any inherent patterns in the timing of lymphocyte and monocyte recovery had prognostic value post-HSCT, we performed unsupervised hierarchical clustering on the longitudinal hematopoietic parameters studied in this cohort and identified four clusters of patients, clusters A-D. Patient clusters A and C both demonstrated improved ALC and AMC recovery at the day +60 and day +100 time points and had significantly improved OS compared with clusters B and D (not reached for A and C vs. 54.9 and 22.3 months, respectively, p<0.001). No patient in cluster D had a day +100 AMC > 0.3 × 10(9) cells/L, and these patients experienced more acute GVHD (p=0.006) and relapse (8 of 14 patients, p=0.002) compared with clusters A, B, and C (p=0.002). 29 patients who were unable to be clustered with this algorithm, predominantly due to early toxic deaths, had a median survival of 6 months. Consistent with previous observations in our myeloablative cohort, both lymphocyte and monocyte recovery are predictive of overall survival post-RIC HSCT. However, compared to the myeloablative cohort, monocyte recovery in this series appears slightly less strongly associated with survival. Our results also extend the observation of improved survival of ALC and AMC recovery post-HSCT to diseases beyond acute leukemia. Disclosures: No relevant conflicts of interest to declare.