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• HCT outcomes in ALL patients after Flu/Mel conditioning & Tac/Siro GVHD prophylaxis. • OS and PFS at 4 years were 58% and 44%, respectively. • Cumulative incidences of relapse and NRM at 4 years were 34% and 22%, respectively. • Patients with Philadelphia chromosome–positive (Ph+) status had lower relapse. • This regimen had favorable outcomes in adult ALL patients with Ph+ status. Acute lymphoblastic leukemia (ALL) is associated with poor survival in older adults, and allogeneic hematopoietic cell transplant (HCT) with reduced-intensity conditioning (RIC) has been an increasingly used strategy in this population. At City of Hope we conducted a retrospective analysis of 72 patients who underwent allogeneic HCT with fludarabine and melphalan (FluMel) as the conditioning regimen between 2005 and 2018, from either a matched sibling or fully matched unrelated donor while in complete remission. Tacrolimus and sirolimus (T/S) were used as graft-versus-host disease (GVHD) prophylaxis. Overall survival and progression-free survival at 4 years post-HCT were 58% and 44%, respectively. The cumulative incidences of relapse/progression and nonrelapse mortality at 4 years were 34% and 22%, respectively. Patients with Philadelphia chromosome–positive (Ph+) ALL had a significantly lower cumulative incidence of relapse/progression (20% versus 48% for patients with Ph-negative status, P =.007). In conclusion, RIC HCT with FluMel conditioning and T/S GVHD prophylaxis was associated with favorable outcomes in patients with Ph+ ALL and should be considered as a viable consolidative therapy for adult patients with ALL. [ABSTRACT FROM AUTHOR]

• HCT outcomes were analyzed in r/r ALL patients, after salvage with blinatumomab. • Pre-HCT blinatumomab was given for morphologic (n = 24) or MRD-positive disease (n = 11). • No unusual toxicities or delayed engraftment was observed post-HCT. • Subgroup analysis (MRD/cytogenetics) showed no significant difference in survival. • Blinatumomab may be considered as a safe and effective salvage therapy pre-HCT. Historically, outcomes of adult patients with relapsed acute lymphoblastic leukemia (ALL) who fail to enter remission with conventional chemotherapy are very poor. Blinatumomab, a bispecific CD3/CD19 antibody, has shown remarkable activity in relapsed/refractory (r/r) ALL. Although allogeneic hematopoietic cell transplant (HCT) is the recommended consolidation therapy for patients with r/r ALL who respond to salvage therapy, HCT and toxicity outcomes for those who received blinatumomab salvage and HCT remain largely unknown. We treated 89 patients with r/r ALL with blinatumomab, of whom 43 patients (48%) achieved remission. Here we describe our single-center experience in the subset of patients who responded to blinatumomab salvage therapy for eradication of either gross (n = 24) or minimal residual disease (n = 11) before HCT. Overall survival at 1 and 2 years after allogeneic HCT was 77% and 52%, respectively. Leukemia-free survival at 1 and 2 years were 65% and 40%, respectively. Additionally, with blinatumomab administration pre-HCT, no unusual toxicities such as delayed neutrophil/platelet engraftment or graft failure were observed. Acute grades II to IV graft-versus-host disease (GVHD) at day +100 post-HCT was at 43% and 2-year chronic GVHD was 36%, both comparable with historic control subjects. Finally, results of our subset analysis based on pre-HCT minimal residual disease (MRD) status indicated no significant difference in survival outcomes among patients undergoing transplant in MRD-negative status and the entire cohort. In conclusion, based on results of this study, blinatumomab may be considered as a safe and effective agent for r/r ALL patients before HCT. [ABSTRACT FROM AUTHOR]

• Eculizumab given immediately post-allogeneic hematopoietic cell transplantation (HCT) as thrombosis prophylaxis is feasible. • Post-HCT eculizumab does not appear to delay engraftment. • Post-HCT eculizumab does not seem to increase infections due to encapsulated bacteria. Paroxysmal nocturnal hemoglobinuria (PNH) is frequently seen in the context of other aplastic anemia and myelodysplastic syndromes and is associated with hemolysis and increased thromboembolic events. Allogeneic hematopoietic stem cell transplantation (alloHCT) is the sole curative treatment but is associated with significant morbidity. The terminal complement inhibitor eculizumab reduces hemolysis and thromboembolic events and is the sole Food and Drug Administration-approved therapy for PNH. Prophylactic administration of this agent in the early post-transplantation setting to prevent hemolysis and thrombosis has not been described in the literature. We describe our institutional experience of 8 patients with PNH who underwent alloHCT and who received at least 1 dose of eculizumab within 30 days of alloHCT for prevention of thrombosis and hemolysis. One patient with underlying aplastic anemia who received bone marrow stem cells failed to engraft. Another patient experienced steroid-refractory grade IV acute graft-versus-host disease and died of a fungal infection. The other patients engrafted well; no hemolysis, thrombotic events, or infections associated with encapsulated bacteria occurred in any of the 8 patients. [ABSTRACT FROM AUTHOR]

Chronic graft-versus-host disease (cGVHD) is a late-occurring inflammatory condition post- allogeneic hematopoietic cell transplantation (HCT), which involves multiple distinct interactions among alloreactive dysregulated T and B cells. Prior studies have shown that autoantibodies to platelet-derived growth factor receptor (PDGFR) induce tyrosine phosphorylation and accumulation of Reactive Oxygen Species (ROS), causing expression of collagen type-1 gene through the Ha-Ras-Erk1/2–ROS signaling pathway. We hypothesize that antioxidant markers of inflammation (8-OHdG, total antioxidant levels, CXCL4 and pH2Ax) will be elevated in patients with scleroderma cGVHD compared to patients who do not develop cGVHD or have non-scleroderma cGVHD. Patients (n=36) were consented on an IRB-approved protocol for a cross-sectional single time point biospecimen collection. Patients with established cGVHD (n=29) or ≥2 years post-HCT without clinical manifestations of cGVHD (n=7) were included. Patients with cGVHD were divided into Scleroderma cGVHD (n=14) and Non-scleroderma cGVHD (n=15). Median age was 49 (range: 21-69) and 56 years (range: 18-72) for patients with scleroderma (group 1) and without scleroderma or no GVHD (group 2), respectively. Median prior lines of therapy was 3.2 (range: 2-5) for patients in group 1. All patients is group 1 and 77% of patients in group 2 received PBCSs as the graft source. Transplant was from a matched unrelated (group 1: 75%, group 2: 73%) or a matched sibling donor (group 1: 25%, group 2: 23%). Tacrolimus/sirolimus was the most commonly used GVHD prophylactic regimen in both groups (group 1: 83% and group 2: 64%). Peripheral blood samples were drawn at a single time point post-HCT, and serum samples were used for ELISA assays for levels of total antioxidants, 8-OHdG, and CXCL4. Flow cytometric analysis was performed to investigate percentage of Tregs and pH2AX+ cells. There were no differences in the total antioxidant levels, CXCL4 and Tregs between groups 1 and 2. Using a cutoff threshold of 10 ng/ml of 8-OHdG, 11 patients (78%) in group 1 and 9 patients (40.9%) in groups 2 had elevated levels of 8-OHdG (p=0.029, Fisher's exact). Percentage of pH2AX expressing cells was lower in group 2. At the cutoff threshold of 37%, only one patient (7%) in group 1 and 13 patients (59%) in group 2 had more than 37% pH2AX-expressing CD45+ cells in their peripheral blood (p=0.002, Fisher's exact). In conclusion, our pilot cross-sectional study showed that scleroderma cGVHD is associated with increased ROS levels (8-OHdG) without elevation of pH2AX cells in peripheral blood T cells. Our results indicate that ROS elevation in scleroderma patients may be a stress response to inflammatory milieu and is independent of DNA damage. Our data justify further prospective cohort studies to define the role of ROS markers in scleroderma cGVHD and to develop novel strategies to treat/prevent cGVHD. [ABSTRACT FROM AUTHOR]

There is a paucity of information on late-occurring (≥1y) infectious complications in contemporary survivors of hematopoietic cell transplantation (HCT). Addressing these knowledge gaps can help tailor post-HCT infection surveillance and proactive immune reconstitution practices in this growing population. Patients were eligible if they underwent a first HCT at City of Hope between 2010 and 2013, and were alive and in remission at 1y post HCT; 696 were eligible and included in this study. Standardized (national guidelines) definitions were used to determine the occurrence of late-occurring (≥1y after HCT) severe/life-threatening/fatal bacterial, viral and fungal infections. Infections that occurred within 4 weeks of a previous one were considered polymicrobial. Follow-up was censored at relapse, subsequent malignancy, death, or December 31, 2017, whichever occurred first. Chronic GVHD (cGVHD) was categorized as none, mild, moderate/severe at 1y post HCT. We determined the cumulative incidence of: first, polymicrobial, vaccine-preventable, and subsequent infection (>4 weeks from initial infection), taking into consideration competing risk. We used multivariable regression (hazard ratio [HR], 95% confidence interval [CI]) to adjust for relevant covariates. Median age at HCT was 53.3y (range, 0.7y-78.1y); 58.5% were male; 73.1% were non-Hispanic white; 57.2% underwent allogeneic HCT; 42.8% were at high risk of relapse; 69.1% received myeloablative conditioning. Overall, 194 (27.9%) developed a late infection; 75 (10.8%) had at least one vaccine-preventable infection. Median time to first infection was 1.8y (range, 1.0-6.6y) from HCT. The 5y cumulative incidence of a late infection was 28.6%; 5y incidence of vaccine-preventable infection was 11.7%; 5y incidence of polymicrobial infection was 6.4%; and there was a steep increase in the incidence of each subsequent infection (Fig 1). Survivors of allogeneic HCT had a significantly higher 5y incidence (Fig 2), and the incidence was highest in patients with moderate/severe cGVHD at 1y post-HCT (Fig 3). Overall, there was a four-fold risk among allogeneic compared to autologous patients (HR 4.11; 95%CI 2.83-5.97; p<0.001). Mild cGVHD at 1y was associated with a 1.96-fold (95% CI 1.06-3.61) risk, while moderate/severe cGVHD was associated with a 3.61-fold (95% CI 1.98-6.58) risk of developing a late-occurring infection (reference: no cGVHD). Nearly one third of long-term HCT survivors developed a severe/life-threatening/fatal infection, and one in ten developed a vaccine-preventable infection. Allogeneic HCT survivors had a higher risk than autologous survivors, due in part to cGVHD and its management. There was a steep increase in risk of subsequent infections with each infectious episode, emphasizing the need for closer monitoring and prevention strategies in these patients. [ABSTRACT FROM AUTHOR]

Despite of the continuous increase in the number of volunteer donors available through the registry, many patients who require an allogeneic hematopoietic cell transplantation (HCT) cannot find a fully-matched donor. While a mismatched unrelated donor (MMUD) is frequently available, it is associated with inferior outcomes and increased risk of graft-versus-host disease (GvHD). Post-transplant cyclophosphamide (PTCy) has been effective in haploidentical HCT, and increasingly used in matched donor HCTs. However, limited data exist in MMUD setting. We conducted a prospective single center trial (NCT 03128359) of PTCy for MMUD HCT with the primary objective of estimating 1-year GvHD-free relapse/progression-free survival (GRFS). As of October 2019, all planned 39 patients have been enrolled with a median follow up of 11 months (range: 1-23). Here we present the preliminary estimate of 1-year GRFS and other HCT outcomes in two strata; myeloablative conditioning (n=19) using Fludarabine (90 mg/m2) and FTBI (1200 cGy) or reduced intensity conditioning (n=19) using Fludarabine (100 mg/m2) and Melphalan (140 mg/m2 or 100 mg/m2 if >60 years old). Patients between 0 to 75 years of age and KPS of ≥70% with hematologic malignancies undergoing HCT from a 7/8 HLA-matched (A-, B-, C-, and DR-) donor were eligible. Patients with donor specific antibodies to the mismatched HLA-locus were excluded. All patient received PBMCs (3-5 × 106/kg) followed by GVHD prophylaxis consisting of PTCy (50 mg/kg for 2 days), Tacrolimus (1 mg), and mycophenolate mofetil (1 gr 3 × a day). Median age at the time of HCT was 53 years (range: 21-72), and 50% of patients were male. Disease risk was low in 47% (n=18), intermediate in 37% (n=14), and high in 16% of the patients (n=6). At transplant, 29 patients were in complete remission, and 9 had active disease. HCT-CI was 0 in six (16%) and 1-2 in 15 (39%) and >2 in 17 (45%) patients. Donors' median age was 32 years (range: 19-53) and donors were mismatched at HLA-A (n=14), -B (n=12), -C (n=8), or DR-loci (n=5). Median number of mismatches was 2 of 12 (range: 1-4). Female to male donor HCT was in 11% of recipients. Neutrophil engraftment occurred in all patients (median time to engraft: 16 days; range 13-35). One-year overall survival (OS) and GRFS were 92% (95% CI: 70-98) and 70% (95% CI: 51-83), respectively. Non-relapse mortality and relapse rate at 1 year were at 8% (95% CI: 2-29) and 13% (95% CI: 5-34), respectively. Cumulative incidence of day 100 acute GvHD grade 2-4 was 50% (95% CI: 35-71) and 1-year chronic GvHD was 56% (95% CI: 39-81). No severe chronic GvHD by the NIH criteria was observed. In conclusion, the data from our phase II trial of PTCy showed highly promising OS/GRFS in patients receiving 7/8 MMUD HCT, and that PTCy in MMUD setting offers an alternative and effective HCT approach for patients who do not have an available matched donor. [ABSTRACT FROM AUTHOR]