ALBERT

Description: Key Points Plasma concentrations of CXCL9 are elevated at the onset of cGVHD diagnosis, but not in patients with cGVHD for more than 3 months. Plasma concentrations of CXCL9 are impacted by immunosuppressive therapy.

Description: MRD detected by flow cytometry (FC) or PCR has been associated with key outcomes after HCT for ALL. In a prospective multicenter trial (NCT02646839; Pediatric Blood and Marrow Transplant Consortium [PBMTC] ONC1401), we performed a planned sub-study of NGS-MRD to predict outcomes pre- and post-HCT for ALL patients (n=57, median follow-up 523 [range 58-1198] days post-HCT). In addition, we performed analyses of relevant clinical factors to assess their relationship to EFS. The larger trial studying the role of KIR favorable haploidentical vs. other transplantation approaches for children diagnosed with ALL, acute myeloid leukemia and myelodysplastic syndrome will be reported separately. We evaluated baseline blast samples from 74 patients for dominant BCR/TCR rearrangements and to follow MRD by NGS. Dominant rearrangements were identified in 100% of B-ALL patients, 96.8% (61/63) in BCR and 3.2% in TCR gamma. For T-ALL patients, rearrangements were identified in 62.7% (7/11), with the remaining 37.3% being polyclonal. Patients proceeded to HCT only if they were in morphological remission. Pre-HCT NGS-MRD from bone marrow (BM) was highly predictive of EFS (n=29 P=0.027, Figure 1) and although NGS-MRD from peripheral blood (PB) did not reach statistical significance due to decreased sample size (n=27, P=0.17, Figure 2), it trended similarly. In BM NGS-MRD negative patients, relapse was exceptionally low with all events due to transplant related mortality (TRM). There did not appear to be a benefit of acute graft-vs-host-disease (aGVHD) in NGS-MRD- patients (Figure 3) or chronic (c)GVHD, but sample size was a limitation. Pre-HCT, 10% of the BM samples were MRD+ by FC, but 35% were MRD+ by NGS. Direct comparison of NGS-MRD in BM and PB with FC MRD pre- and post-HCT showed improvements positive and negative predictive power (data not shown). Alpha/beta depleted haploidentical grafts had similar outcomes to other stem cell sources (Figure 4) with decreased incidence of GVHD [aGVHD 〉 grade 2: n=1 (3.3%) and extensive cGVHD: n=1(3.3%)]. TBI (total body irradiation) based myeloablative conditioning (TBI/TT [Thiotepa]/CY [Cyclophosphamide], TBI/CY, or TBI/VP16; ± anti-thymocyte globulin [ATG]) and non-TBI reduced toxicity (Flu [Fludarabine]/Mel [Melphalan]/TT; ± ATG) had identical EFS (P= 0.31). TRM was very low 8.7%(n=5) in this population (n=57)) and rescue of relapse was high for the duration of follow up to date, resulting in similar OS for MRD- vs. MRD+ patients (P= 0.15), likely due to rescue with cell/immunotherapy. We next examined the interaction of obesity, using body mass index (BMI) based on height/weight pre-HCT, in the context of NGS-MRD on EFS. The BMI score was converted to a percentile through population norms for age and gender and defined thresholds published by the Centers for Disease Control and prevention (CDC). Lean patients (〈 85th percentile [%]) overall had better survival than the overweight (OW)/obese (85-94%/≥95%) (Figure 5: P=0.016). But among the lean patients, NGS-MRD still had an effect, with NGS-MRD+ patients had poorer EFS. Same was observed with the OW/obese group, where being NGS MRD+ adds further reduction in survival. Overweight/Obese patients who were pre-HCT MRD- had survival closer to the lean/MRD+ patients. We observed decreased EFS by weight category and NGS-MRD (Figure 6: P= 0.02). In conclusion, NGS-MRD was highly predictive for EFS regardless of HCT preparative approach or graft Alpha/Beta Depletion. NGS improved predictive power for MRD positivity compared to FC. NGS was able identify rearrangements suitable for MRD tracking in all B-ALL and in most of T-ALL samples. In BM NGS-MRD negative patients, relapse was exceptionally low. There did not appear to be a benefit of aGVHD or cGVHD in NGS-MRD- patients. Alpha/beta depleted haploidentical grafts had similar outcomes to other stem cell sources with decreased incidence of severe GVHD. We observed decreased EFS by weight category and NGS-MRD. Lean patients had better survival, after HCT, than OW/Obese patients. But among the lean patients, NGS-MRD+ patients had poorer EFS. Disclosures Abdel-Azim: Adaptive: Research Funding. Dvorak:Jazz Pharmaceuticals: Consultancy; Alexion Inc: Consultancy. Bunin:PRA Health Sciences: Other: Immediate family member employed. Walters:Editas Medicine: Consultancy; TruCode: Consultancy; AllCells, Inc: Consultancy. Cairo:Jazz Pharmaceuticals: Other: Advisory Board, Research Funding, Speakers Bureau; Miltenyi: Other: MTA; Osuka: Research Funding. Kitko:Novartis: Consultancy, Honoraria; Mallinckrodt: Honoraria. Jacob:Adaptive Biotechnologies: Employment, Other: shareholder. Wing:Miltenyi Biotec: Employment. Pulsipher:Medac: Honoraria; Miltenyi: Research Funding; Bellicum: Consultancy; Amgen: Other: Lecture; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz: Other: Education for employees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: Relapse of malignancy and lethal graft versus host disease (GVHD) are the principal causes of failure of allogeneic hematopoietic cell transplant (HCT). Recently we have shown that at seven days after HCT an algorithm using two serum biomarkers (ST2 and REG3α) can predict severe GVHD (Hartwell et al. JCI Insight 2017). We determined whether serial testing (in the first month following HCT) of patients with low probability biomarkers would improve the predictive accuracy of the algorithm and identify patients with different risks of relapse and lethal GVHD. Patients who received an HCT at 18 centers in the Mount Sinai Acute GVHD International Consortium (MAGIC) for hematologic malignancy and who supplied three blood samples were divided into a training set and validation set with equal numbers of lethal GVHD events, which was defined as death from GVHD or infection during treatment for GVHD. Patients in the training set (n=702) underwent HCT from January 1, 2006 until June 30, 2015, whereas patients in the validation set (n=906) underwent HCT from July 1, 2015 to May 1, 2017. Serum samples were analyzed using the previously published algorithm of two biomarkers up to three times (day 7, day 14, day 28 or GVHD onset, if onset occurred within the first 28 days). The algorithm generates a predicted probability of lethal GVHD between 0 and 1 for each patient. Patients were categorized as either low probability (LP) or high probability (HP) for lethal GVHD. HP thresholds of 0.20 and 0.16 were used to classify patients with and without GVHD symptoms, respectively (once categorized as HP, patients remained in that category and were not retested). All results were similar between training and validation sets, and we present here the validation set results. Serial testing identified 28% of patients as HP with a three-fold greater cumulative incidence of lethal GVHD at one year (13% vs 4%, p

Description: Following up on single institution studies suggesting that engaging patients in exercise and/or stress reduction techniques during hematopoietic cell transplantation (HCT) improves functional status and quality of life, we conducted a randomized study through the Blood and Marrow Transplant Clinical Trials Network (BMT CTN). METHODS: Patients (n=711) at 21 US centers provided symptom and quality of life data at enrollment. They were randomized to 1 of 4 groups using a 2x2 factorial design, stratified by center and transplant type. Prior to HCT, each group received a 15 minute stress management training session or a 15 minute exercise training session, both, or neither, with trained personnel to discuss the importance of managing stress and/or keeping active during HCT. The 3 intervention groups were also given a DVD, pamphlet and diary to track participation in exercise and/or stress management. The trainer reviewed the goals of practicing the intervention, proper technique, identification of barriers and plans to overcome them. Exercise training also included calculation of target heart rate. The exercise goal was walking 3-5 times a week for at least 20-30 minutes at 50-75% of estimated heart rate reserve. The stress management goal was to use paced abdominal breathing, progressive muscle relaxation with guided imagery, and coping self-statements to decrease stress. The interventionists re-contacted patients at 30 and 60 days after HCT to review the training goals, discuss barriers and provide encouragement. The fourth group was a usual care control group. All groups received a DVD of general information about HCT. Participants provided self-reported assessments at 30, 60, 100 and 180 days after transplant. The primary endpoints were the physical (PCS) and mental (MCS) component subscales of the SF36 at day 100. The study was designed to have 85% power to detect a difference of 0.5 STD in the exercise or stress management groups on each of the two endpoints, maintaining an overall type I error rate of 0.05. Primary analysis was on an intention to treat (ITT) basis with values assigned to patients who died or otherwise did not provide information. Enrollment occurred from January 2011-June 2012. Results The groups were well-balanced for baseline characteristics. There were no differences in the primary endpoints of PCS and MCS at day +100 among any of the groups based on the ITT analysis (Table). Results were similar using other conditional and imputed methods. Higher PCS at day +100 was associated with higher PCS at enrollment (p

Description: No validated biomarkers exist for acute graft-versus-host disease (GVHD). We screened plasma with antibody microarrays for 120 proteins in a discovery set of 42 patients who underwent transplantation that revealed 8 potential biomarkers for diagnostic of GVHD. We then measured by enzyme-linked immunosorbent assay (ELISA) the levels of these biomarkers in samples from 424 patients who underwent transplantation randomly divided into training (n = 282) and validation (n = 142) sets. Logistic regression analysis of these 8 proteins determined a composite biomarker panel of 4 proteins (interleukin-2-receptor-alpha, tumor-necrosis-factor-receptor-1, interleukin-8, and hepatocyte growth factor) that optimally discriminated patients with and without GVHD. The area under the receiver operating characteristic curve distinguishing these 2 groups in the training set was 0.91 (95% confidence interval, 0.87–0.94) and 0.86 (95% confidence interval, 0.79–0.92) in the validation set. In patients with GVHD, Cox regression analysis revealed that the biomarker panel predicted survival independently of GVHD severity. A panel of 4 biomarkers can confirm the diagnosis of GVHD in patients at onset of clinical symptoms of GVHD and provide prognostic information independent of GVHD severity.

Description: Abstract 675 We have previously identified five biomarker proteins that have diagnostic and prognostic value for acute graft-versus-host disease (GVHD) (Blood 113:273-278, Sci Transl Med 2:50-57). In order to determine whether biomarkers can predict GVHD before the appearance of clinical symptoms, we evaluated the three most informative biomarkers of the five (IL2-Receptor-α, TNFR1, elafin) in patient samples prospectively collected between 2000 and 2010 from 513 unrelated (URD) hematopoietic cell transplant (HCT) patients. We focused on URD HCT recipients because they are most likely to develop acute GVHD and could potentially benefit from a predictive laboratory assay and subsequent preemptive intervention. We measured biomarker plasma levels by sequential enzyme-linked immunosorbent assay on samples obtained prior to conditioning (pre-HCT), and at day +7 and day +14 after HCT. In designing the analytical approach, we took into consideration that median time to GVHD onset is delayed after reduced intensity conditioning, that there may be limited opportunity to preemptively intervene in patients on the verge of developing GVHD, and that there have been changes in GVHD prophylaxis agents over the past decade. Therefore, we randomly divided the patients into training (N=342) and validation (N=171) data sets that were balanced for (i) full intensity conditioning, (ii) onset of grade II-IV GVHD earlier than day +21 and (iii) HCT performed after 2005. In order to create a prediction model for acute GVHD, we used the biomarker levels in the training data set to simulate biomarker values for a hypothetical 50,000 patients using the following assumptions: (1) the incidence of GVHD by day 100 is 55%, (2) the median day of GVHD onset after full intensity URD HCT is day 21, with 10% of patients developing GVHD prior to day +7, and 3% developing GVHD after day +56. These assumptions were based on historical URD HCT data at our center. We used logistic regression to compute a predicted probability, p7, of developing grade II-IV GVHD for each of the 50,000 patients based upon the biomarker levels pre-HCT and at day +7. Any patient with p7≥0.64 was categorized as high risk for development of GVHD. For all low risk patients (p7

Description: Graft-versus-host disease (GVHD) is a principal cause of morbidity and mortality following allogeneic hematopoietic cell transplant (HCT). Standard therapy for GVHD, high dose steroids, results in complete responses in only 35% of patients. Because tumor necrosis factor-α (TNFα) is an important effector of GVHD in animal models we treated 61 pts with new onset GVHD with methlyprednisolone 2 mg/kg/d plus etanercept, a TNFα inhibitor. All pts continued their GVHD prophylaxis agent, usually tacrolimus, at therapeutic dosing. Etanercept was given subcutaneously twice weekly for 8 wks at a dose of 0.4 mg/kg/dose (maximum dose 25 mg). The outcomes in these 61 pts were compared to those of 99 contemporaneous pts with GVHD whose initial therapy was steroids alone. Both groups of pts were similar with respect to age, transplant conditioning intensity, donor type and degree of HLA-match, and severity of GVHD at onset. Pts treated with etanercept plus steroids were significantly more likely to achieve a complete response 4 wks later than were pts treated with steroids alone [69% (95% CI: 57%, 81%) vs 33% (95% CI: 24%, 42%), p

Description: Pulmonary complications are common following hematopoietic stem cell transplantation (HSCT). The role of fiberoptic bronchoscopy with broncho-alveolar lavage (BAL) in recipients of reduced-intensity (RI) and full intensity (FI) transplants is now reported. Between January 2001-May 2008, 803 allogeneic transplants (212 RI, 591 FI) were performed on 784 patients at the University of Michigan Medical Center. Pulmonary complications, defined as either hypoxia 〉 24 hours, or clinical/radiographic features of pneumonitis, were identified in 313 (39.9%) patients post-transplant. Bronchoscopy was performed on 265 (84.7%) patients with pulmonary complications, including 69 patients undergoing RI transplants (median age 56 yrs, 10–68 yrs) and 196 patients undergoing FI transplants (median age 41 yrs, 1–64 yrs). The time to BAL was similar for recipients of RI when compared to recipients of FI transplant [median: 89 days (0–1854 days) vs. 104 days (7–1533 days)]. Pathogenic organisms were identified in 31.8% (RI) and 25.2% (FI) of BAL procedures. Invasive fungi were the most commonly identified organisms, identified on 48.1% (RI) and 45.2% (FI) of BALs in which pathogens were noted. The incidence of bacterial, viral (including CMV), and mycobacterial pulmonary infections were similar in recipients of RI and FI transplants. The frequency with which pathogens were identified varied with the timing of the bronchoscopy (see Table), with non-infectious pulmonary complications twice as likely to occur in the first 100 days post-transplant in FI than RI transplant recipients (p 〈 0.05). The BAL led to a change in medical management in 54.1% (RI) and 59.3% (FI) of cases respectively, with modifications in antimicrobial therapy in 38.8% (RI) and 42.1% (FI). The bronchoscopy led to modifications in immunosuppressive therapy in 27.1% (RI) and 27.6% (FI) of cases. BAL procedural related complications were rare in both groups, with pulmonary hemorrhage and transient hypoxemia occurring in 〈 2.5% of all patients undergoing a BAL. Conclusion: The incidence of pulmonary complications, as evaluated by bronchoscopy post HSCT, was similar for recipients of RI and FI conditioning regimen. Within the first 100 days post-transplant, non-infectious etiologies for pulmonary dysfunction were significantly more common in FI than RI patients. There were no other significant differences in the timing of pulmonary complications or the type of pathogenic organisms identified following a FI or RI transplant. Broncho-alveolar lavage is a safe procedure in patients following allogeneic transplants, altering medical management in over 50% of cases. Time post-transplant and % BAL with a pathogenic organism identified Day 0–100 * Day 〉 100 Total RI 32.4% 31.3% 31.8% FI 15.8% 31.8% 25.2%

Description: Abstract 35 Patients with hematologic malignancies who are not in remission prior to allogeneic hematopoietic stem cell transplantation (HSCT) have a poor prognosis. In an effort to improve the anti-tumor activity of conditioning without added toxicity, we combined clofarabine, which is known to have a significant anti-leukemia activity, with myeloablative doses of busulfan in a phase I/II study in non-remission hematologic malignancies. Busulfan was administered as a single daily dose of 3.2 mg/kg IV × 4d (days -5 to -2) and clofarabine as a single daily dose of 20, 30 or 40 mg/m2 IV × 5d (days -6 to -2) with the specific dose determined by the Time to Event-Continuous Reassessment Method (TITE-CRM). All pts received dexamethasone 12 mg IV on the days of clofarabine to prevent capillary leak syndrome. Graft-versus-host-disease (GVHD) prophylaxis was tacrolimus/MMF in all but one patient (tacrolimus/methotrexate). Forty six pts were enrolled. Characteristics of pts are shown in table 1. Prior to HSCT, pts failed an average of 3 regimens (range: 1–5), none were in remission, and 68% of leukemic pts had peripheral blasts. The majority received unrelated and / or HLA mismatched grafts. CloBu4 was generally well tolerated. Grade 3–4 non-hematological toxicities observed from initiation of conditioning to day +30 include: transient transaminitis (50%), mucositis (26%), hand-foot syndrome (13%), transient hypoxia (13%), nausea/vomiting (11%), diarrhea (11%), hypertension (7%), veno-occlusive disease (4%), hyperbilirubinemia (4%), hypersensitivity (2%), joint pain (2%) and seizure (2%). There were no cases of renal insufficiency and all cases of transaminitis resolved to ≤grade 1 within 14 days. All patients engrafted (median 11 days for neutrophils [range: 9–16]; 10 days for platelets [range: 1–20]. Lineage specific chimerism was analyzed at day 30, 100, 180, and 365. Full donor chimerism in CD3 lineage was achieved in 54%, 75%, 94% and 100% of pts on days 30, 100, 180 and 365, respectively. Absolute CD4 counts were 228±170, 238±147 307±151, and 341±184 cells/μ l on days 30, 100, 180, and 365, respectively. Acute GVHD (≥ grade 2) occurred in 48% of pts and resulted in five deaths. Overall, 80% of pts achieved CR by day +30 (AML = 94%, Others = 53%, AML without prior allo HSCT = 100%). Cumulative incidence of relapse in AML patients was 38%. The median duration of remission for AML pts was 15.4 months (range 2–34 m). Non-AML pts experienced a higher incidence of relapse/progression (67%, p=0.008) and shorter remissions (8.6 m, range 2–29 m). At a median follow up of 18 months, overall survival for the entire cohort was 42% at 18 months post-transplant (50% for AML, n=31). In conclusion, these data suggest that clofarabine combined with myeloablative doses of busulfan is well tolerated, facilitates engraftment, and has significant anti-tumor activity, particularly in patients with non-remission AML at HSCT. Given that CloBu4 reliably led to remissions that lasted a median of 15.4 months in non-remission AML pts, this regimen may provide a platform for further interventions such as maintenance therapy for this population of pts. Disclosures: Mineishi: Genzyme: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding. Off Label Use: Clofarabine use for transplant conditioning regimen. Erba:Genzyme: Consultancy, Honoraria, Research Funding.

Description: Graft-vs-host disease (GVHD) remains the major cause of morbidity and treatment-related mortality (TRM) after allogeneic HSCT, but there are no independent laboratory tests to either predict or confirm the clinical diagnosis of GVHD. Pre-clinical studies have shown that tumor necrosis factor-α (TNF) plays an important role in the pathogenesis of GVHD and that TNF plasma levels rise often several weeks before clinical disease becomes apparent. We tested the hypothesis that rises in TNF (on day 7 following allogeneic HSCT) will predict the development of significant GVHD and treatment-related mortality (TRM). We measured soluble TNF receptor 1 (TNFR1) as a surrogate for TNF because TNF circulates as a ligand-receptor complex. We studied samples obtained under informed consent from 438 patients undergoing allogeneic HSCT following myeloablative conditioning at the University of Michigan between 2000 and 2005. The conditioning regimens were based on Busulfan (68%), BCNU (20%), or TBI (12%). The median age of the patients was 42y (range 0–65y). The distribution of donors by degree of HLA-match and type was: 6/6 HLA-matched related donors (n=247), 5/6 matched related donors (n=20), 6/6 matched unrelated donors (n=124), 5/6 matched unrelated donors (n=47). Hematologic malignancy was the indication for 95% of HSCT. The median day of onset of GVHD grade 2–4 for related donors was 30d and for unrelated donors was 20d. Because of the variablilty in baseline TNFR1 levels, we expressed the day 7 value as a ratio to pre-transplant baseline. The mean day 7 TNFR1 ratio strongly correlated with severity of GVHD. The mean TNFR1 ratio was 1.91±0.09 for pts with GVHD 0–1 (n=269), 2.32±0.20 for pts with GVHD 2 (n=83), and 2.92±0.26 for pts with GVHD 3–4 (n=86), p