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Immunologie disparities between minor histocompatibility antigen (mHAg) genes on Y (H-Y) and X (H-X) chromosomes contribute to graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effects observed in male recipients of a female donor (FtoM) hematopoietic stem cell transplant (HCT). Using in silico prediction tools, a panel of HLA-A0201 restricted H-Y peptides was synthesized. Expression of CD137 was monitored on CD8+ T cells after brief stimulation with the H-Y peptides in FtoM HLA-A0201 HCT recipients (N = 29), and control groups (HLA-A0201 MtoM[N= 18],non-HLA-A0201 FtoM [N = 14], and HLA-A0201 female volunteers [N = 25]). Specific H-Y responses were significantly greater in HLA-A0201 FtoM than controls. CD8+ T-cell responses to novel H-Y epitopes were shared among multiple patients, showing marked CD45RA+CD27 cytolytic effector profiles. These data represent a proof of concept for our in silico/ex vivo CD8+ T-cell based approach of prediction and validation of H-Y mHAgs in HCT recipients, which may facilitate prospective studies to identify targets/biomarkers of GVHD/GVL. [ABSTRACT FROM AUTHOR]

Abstract: We studied the morphological behavior of two-dimensional (2D) structures fabricated by two-photon excitation of silver nitrate in poly(N-vinylpyrrolidone) (PVP) matrix. The 2D structures at two different positions toward depth direction were fabricated on a microscope stage. Obtained structures were investigated using an atomic force microscopy (AFM), a scanning electron microscopy (SEM), an energy dispersive X-ray spectrometry (EDX), and an X-ray photoelectron spectroscopy (XPS). AFM measurement showed the photo-induce structure on a cover slip. EDX and XPS measurements showed that the silver ion was photo-reduced and the photo-reduced silver was interacted with PVP, respectively. [Copyright &y& Elsevier]

Abstract: We report a consecutive series of 59 patients with MDS who underwent reduced-intensity hematopoietic stem cell transplantation (RI-HSCT) with fludarabine/melphalan conditioning and tacrolimus/sirolimus-based GVHD prophylaxis. Two-year OS, EFS, and relapse incidences were 75.1%, 65.2%, and 20.9%, respectively. The cumulative incidence of non-relapse mortality at 100 days, 1 year, and 2 years was 3.4%, 8.5%, and 10.5%, respectively. The incidence of grade II–IV acute GVHD was 35.4%; grade III–IV was 18.6%. Forty of 55 evaluable patients developed chronic GVHD; of these 35 were extensive grade. This RI-HSCT protocol produces encouraging outcomes in MDS patients, and tacrolimus/sirolimus-based GVHD prophylaxis may contribute to that promising result. [Copyright &y& Elsevier]

Abstract: Peripheral blood stem cells (PBSC) have been increasingly used in the matched unrelated donor (MUD) transplant setting, but the impact of CD34+ cell dose on outcomes in this setting have not been well characterized. We analyzed 181 consecutive patients who underwent MUD-PBSC transplantation at the City of Hope between August 2000 to December 2004. Patients were conditioned with either full-intensity regimen or reduced-intensity regimen. There was a significant inverse relationship between higher CD34+ cell dose and faster neutrophil engraftment (r = −0.16, P = .035). By univariate analysis, a CD34+ cell dose ≥4.2 × 106/kg (above the lowest quartile) was associated with significantly lower relapse risk (hazard ratio [HR] = 0.67, P = .0126), with a trend for corresponding improvement for disease-free survival (HR = 0.84, P = .12) but not overall survival (HR = 0.91, P = .46). The impact of the CD34+ cell dose remained significant in multivariate analysis. The higher CD34+ cell dose was significantly associated with faster recovery of absolute lymphocyte counts on day +30 posttransplant. Subset analysis demonstrated that the higher CD34+ cell dose was associated with (1) greater reduction in relapse in myeloid malignancies than that in lymphoid malignancies, (2) greater reduction in reduced-intensity conditioning than in full-intensity conditioning, (3) greater reduction in relapse when there is a inhibitory killer-cell immunoglobulin-like receptor ligand (iKIRL)-mismatch in the gravft-versus-host (GVH) direction, and (4) greater reduction in relapse when there is a lack of iKIRL, suggesting that the protective effect of CD34+ cell dose against relapse may be immune-mediated, possibly through NK cell recovery. [Copyright &y& Elsevier]

Numerous clinical studies link cytomegalovirus (CMV) infection with incomplete posttransplantation T-cell recovery. We hypothesized that the inability of transplant recipients to handle CMV reactivation might correlate with a defective graft-versus-leukemia response and increased posttransplantation morbidity. Between May 1995 and August 2001, 82 patients who were CMV seropositive and survived the first 100 days after transplantation were identified for a day 100 landmark analysis of the effect of CMV reactivation patterns on eventual transplantation outcome. All patients underwent a myeloablative HLA-identical sibling donor T cell-depleted stem cell transplantation with scheduled donor T-cell add-back on day 45. Median follow-up was 1032 days. Forty-two patients who had either no reactivation or only 1 positive test with quick clearance were designated as a CMV immune competent group. Forty patients designated as CMV immune deficient (ID) had at least 2 positive tests. Apart from younger age (33 versus 38 years; P = .05) in the ID group, the 2 groups were balanced for clinical characteristics. In multivariate analysis, ID patients had a significantly higher incidence of leukemia relapse (58% versus 21%; P = .03) and worse disease-free survival (31% versus 66%; P = .04). There was no significant difference in week 1 to 14 posttransplantation lymphocyte counts between the 2 groups. In 67 patients tested 3 to 6 months after transplantation, a proliferative response to CMV antigen (stimulation index ≥2) occurred in 27 of 36 immune competent patients compared with 15 of 31 ID patients (P = .006). These results show that recurrent CMV reactivation in the first 100 days after transplantation predicts for reduced disease-free survival and increased leukemic relapse beyond 100 days and correlates with inferior proliferative responses to CMV. The higher relapse rate may reflect poor immune reconstitution in ID patients or an adverse effect of prolonged antiviral treatment. [Copyright &y& Elsevier]

Background Early CMV reactivation remains a significant cause of morbidity/mortality in allogeneic hematopoietic cell transplant (HCT) recipients. CMVPepVax is an investigational peptide vaccine based on an HLA-A0201-restricted immune-dominant peptide (pp65 495-503). In a randomized Phase 1b trial, CMVPepVax (given on days 28 & 56 post-HCT) demonstrated safety, immunogenicity, and reduced CMV reactivations (Lancet Haem 2017). In the current study, we assessed the detailed phenotypes and time-courses of the pp65-specific CD8 T cell subsets that expanded in response to CMVPepVax vaccination. Patients (pts)/methods Of 18 pts in the vaccine arm (VA) and 18 in the observation arm (OA), 12 VA and 8 OA pts were included for the current study as they developed levels of CMV-specific T cells evaluable for memory phenotyping. Eleven of the 12 VA pts did not reactivate CMV during the 6-month while 5 OA and 1 VA pts developed viremia requiring antiviral treatment. The differentiation status of CMV-specific CD3+CD8+ T cells, identified by pp65 495-503 dextramers, was determined based on CD28/CD45RA expression using polychromatic flow cytometric panels. CD137 expression assay was used to evaluate T cell responses to pp65 or IE1 peptide library. Results The VA pts more often achieved ³0.2% levels of pp65 495-503 -specific CD8 T cells in the absence of clinically detectable CMV viremia (10 non-reactivating pts of 17 in the VA vs. 1 non-reactivating pts of 12 in the OA, p=0.008). Phenotype proportions are displayed in Figure 1. In contrast, when T cells were stimulated with pp65 or IE1 peptide libraries encoding T cell epitopes specific for a variety of HLA alleles, the T cell responses measured by CD137 expression in both VA and OA pts did not significantly differ. These results suggest that the enhanced pp65 495-503 response measured in the VA pts (without viremia) was likely driven by PepVax. When the differentiation status was analyzed, pp65 495-503 -specific T cells in viremic OA pts had a median % of effector phenotype profiles of 91% (range: 31-99%), similar to those of the evaluable non-viremic VA patients, for whom the median % of effector phenotype profiles was 93% (range: 13-100%). Importantly, 2 weeks after the 2nd PepVax vaccination, >80% of pp65 495-503 -specific T cells were TEM and TEMRA in 9 out of the 10 evaluable VA pts. Thus, in these HCT recipients who did not develop CMV viremia, PepVax rapidly expanded CMV-specific T cells with substantial EM profiles. Figure 2 depicts longitudinal dynamic of pp65 495-503 -specific CD8 T cells and their memory profiles. Conclusion Collectively, our analysis indicates that, in the absence of clinically relevant viremia, CMVPepVax reconstituted significant levels of differentiated effector memory CD8 T cells specific to the vaccine epitope of pp65 495-503 early post-HCT, which may have been key to the favorable outcomes of the CMVPepVax clinical trial. [ABSTRACT FROM AUTHOR]

• The incidence of AML relapse is reduced with CMV reactivation. • NK cells are involved in CMV-associated protection from AML relapse. • CMV infection trigger/enhance a response by NK expressing activating KIRs. Multiple retrospective studies have demonstrated an association between cytomegalovirus (CMV) reactivation and reduced risk of AML relapse. However, the potential mechanism explaining this association remains elusive. We investigated a homogeneous cohort of 288 adult patients with AML in remission who received allogeneic hematopoietic stem cell transplantation (HCT) from matched sibling/unrelated donors between 1995 and 2011. The 5-year cumulative incidence of relapse was greater in patients without CMV reactivation compared with those with reactivation (30.2% vs. 12.1%, p = 0.001) in a landmark analysis. In multivariate analyses CMV reactivation was independently associated with reduced relapse risk (HR: 0.49 [0.25-0.95], p = 0.036) and increased non-relapse mortality (26.5% vs. 13.1%, p = 0.002) resulting in similar 5-year overall survival (64.5% vs. 59.1%, p = 0.8). In further subgroup analyses the protective effect of CMV reactivation was significant in patients who received HCT from donors with KIR Bx compared to KIR AA (11.7% vs. 29.5%, p = 0.01). Likewise, the protective effect of CMV reactivation was more significant when the donors had 2DS1 activating KIR (11.5% vs. 30.7%, p = 0.05) compared with those without 2DS1 (14.3% vs. 27.5%, p = 0.12). Our data independently confirmed the association between CMV reactivation and AML relapse, suggesting the involvement of donor KIR genotypes and NK cell-mediated graft-versus-leukemia effect. [ABSTRACT FROM AUTHOR]

IL-22 has been shown to support intestinal mucosa after damage through multiple mechanisms, including promotion of epithelial survival and regeneration as well as induction of innate antimicrobial molecules such as REG3. In experimental murine models, aGVHD resulted in elimination of host-derived IL-22-producing cells, IL-22 deficiency increased GVHD mortality and GI pathology, and early initiation of treatment with exogenous IL-22 reduced GI pathology and improved survival. We thus tested if the addition of IL-22 to corticosteroids could promote healing of GI tract injury and improve treatment response in patients with lower GI aGVHD. We conducted a 27-patient open-label, single-cohort, multicenter prospective phase 2 study between 05/16 and 05/19. Eligible pts were ≥ 18 yrs old and had new onset biopsy-proven grade II-IV lower GI aGVHD following an allo-HCT. Pts received F-652 once weekly at a dose of 45 μg/kg x 4 weeks in combination with standard corticosteroid treatment. Primary endpoints included PK, safety, and day 28 lower GI aGVHD response. Additional endpoints included day 56 treatment response, evaluation of changes in gut microbiota by 16S sequencing, and plasma GVHD biomarkers. The study was powered to distinguish between an unpromising response rate of 35% and a promising response rate of 60%. The 27 pts (median age 55 yrs, mostly PBSC recipients) had predominantly stage 2-4 lower GI GVHD (17/27, 63%), with 6/27 (22%) pts having stage 3 and 6/27 (22%) pts having stage 4 disease. All pts had detectable F-652 levels. Overall, 19/27 achieved a day 28 response (70%, 90%CI: 56-79, Fig 1A). Response to treatment based on Ann Arbor Risk, evaluable in 20 pts, was 7/12 (58%) with high, 3/4 (75%) with intermediate, and 4/4 (100%) with low risk biomarkers (Fig 1B). At day 56, 16 pts (59%) remained treatment responders. 3 pts had repeat GI biopsy after treatment and demonstrated improvement in GI epithelial injury (Fig 2). Additionally, in a subset of 17 pts with stool samples collected, microbial diversity and relative abundance of protective commensal Blautia appeared increased in pts with a clinical response to F-652 (p = 0.082 and 0.048, respectively, Fig 3A-B). Serious TEAEs were observed in 11 pts (40%) including enterocolitis (n = 1), pyrexia (n = 1), infection (2 sepsis, 1 device-related, 1 pneumonia, 1 sinusitis), musculoskeletal (n = 2), and respiratory (n = 1). One patient was diagnosed with squamous cell carcinoma 8 months after F-652 treatment. IL-22 in combination with corticosteroids was well tolerated and the 70% lower GI aGVHD response rate met the primary efficacy endpoint. These findings support further development of this approach and provide a proof-of-concept for combining standard immunosuppression with tissue-supportive strategies to enhance recovery of damaged mucosa, promote microbial health, and improve GVHD treatment response. [ABSTRACT FROM AUTHOR]

• The combination of hypomethylating agents with the selective Bcl-2 inhibitor venetoclax (VEN-HMA) as a bridge to allogeneic hematopoietic cell transplantation (alloHCT) is associated with favorable HCT outcomes. • VEN-HMA could allow more patients of older age to proceed to potentially curative alloHCT. • AlloHCT outcomes are particularly good in patients who undergo HCT in complete remission after VEN-HMA therapy. The combination of hypomethylating agents with the selective Bcl-2 inhibitor venetoclax (HMA-VEN) has emerged as a highly active regimen in patients with acute myelogenous leukemia (AML) in both the upfront and relapsed/refractory (r/r) settings. We report our early experience with a cohort of patients who were able to proceed to allogeneic hematopoietic cell transplantation (alloHCT) after HMA-VEN therapy. Thirty-two patients with AML (19 r/r and 13 de novo) with a median age of 62 years underwent alloHCT after HMA-VEN therapy. Twenty-two (68.8%) were in complete remission (CR)/CR with incomplete count recovery at time of HCT. With a median follow up of 14.4 months, the 1-year overall survival (OS) was 62.5%, and disease-free survival was 43.8%. The 1-year nonrelapse mortality rate was 18.8%, and the cumulative incidence of relapse was 37.5%. Among patients who underwent alloHCT in CR, the 1-year OS was 77.3%, and the cumulative incidence of nonrelapse mortality was 9.1%. The cumulative incidence of grade II-IV acute graft-versus-host disease was 43.8%. We conclude that alloHCT after HMA-VEN is therapy associated with favorable allogeneic HCT outcomes in newly diagnosed older patients with AML, as well as those with r/r AML. [ABSTRACT FROM AUTHOR]

• Impact of iron overload (serum ferritin [SF] >2000 ng/mL) on umbilical cord blood hematopoietic cell transplantation (HCT) outcomes was examined. • Overall survival rate at 2 years was significantly lower in patients with higher pre-HCT SF levels (P =.005). • Nonrelapse mortality was significantly higher in patients with higher SF (P =.02). • Significantly faster engraftment was seen in patients with lower SF levels. • Iron overload is a strong adverse prognostic factor for cord blood transplant. The negative impact of iron overload (IO) on outcomes of allogeneic hematopoietic cell transplantation (HCT) is well recognized, but its impact on umbilical cord blood (UCB) transplant outcome is unknown. We retrospectively analyzed outcomes of 150 patients who received UCB-HCT at our institution, stratified by pre-HCT serum ferritin (SF) level of 2000 ng/mL. Two-year overall survival rate among patients with SF >2000 and ≤2000 ng/mL was 26.1% (95% CI, 10.6% to 44.7%) and 52.1% (95% CI, 40.1% to 62.8%), respectively; hazard ratio (HR) = 2.26 (95% CI, 1.28 to 4.00, P =.005). Two-year nonrelapse mortality rate was higher among patients with SF >2000 ng/mL (56.5%; 95% CI, 33.3% to 74.4%) compared to SF ≤2000 ng/mL (30.1%; 95% CI, 20.0% to 40.9%); HR = 2.18 (95% CI, 1.10 to 4.31, P =.025). Neutrophil engraftment at 42 days was 78.3% (95% CI, 53.5% to 90.8%) in patients with SF >2000 ng/mL versus 91.8% (95% CI, 82.1% to 96.4%) in patients with SF ≤2000 ng/mL; HR = 0.58 (95% CI, 0.35 to 0.96, P =.034). A significant difference in platelet engraftment at 3 months was also observed: 52.2% (95% CI, 29.4% to 70.8%) for SF >2000 ng/mL versus 80.8% (95% CI, 69.5% to 88.3%) for SF ≤2000 ng/mL; HR = 0.48 (95% CI, 0.23 to 0.98, P =.044). In conclusion, IO defined by SF of 2000 ng/mL is a strong adverse prognostic factor for UCB-HCT and should be considered when UCB is chosen as the graft source for patients without a fully matched donor. [ABSTRACT FROM AUTHOR]

• 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]

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in hematopoietic cell transplantation (HCT) survivors. In these patients, such risk factors as hypertension, diabetes, obesity, and physical inactivity are important modifiers of CVD risk. However, the period when HCT survivors are at greatest risk of developing these risk factors, and in turn CVD, coincides with a drop in engagement in survivorship care. We examined the feasibility and acceptability of a 4-week remote risk-based monitoring (blood pressure monitor, weight scale, pulse oximeter, glucometer) and management program in 18 (11 allogeneic and 7 autologous) HCT survivors at intermediate-high risk of CVD. The median patient age was 66 years (range, 53 to 74 years), 67% had hypertension, 22% had diabetes, 11% were obese (body mass index ≥30 kg/m2), 56% were at intermediate risk of CVD, and 44% were at high risk of CVD. Weekly compliance with the remote monitoring schedule (≥3 readings/week using all devices) ranged from 72% in week 1 to 83% in weeks 2 to 4. Fifteen participants (83%) generated 86 alerts that were outside the predetermined range of normal; 63 of these readings (73%) normalized without intervention, and 23 (27%) necessitated triage by the study research nurse. Nearly all participants reported that the study kept them motivated and involved in their healthcare, and >85% agreed that the study supported their healthcare goals, helped them learn and manage their health conditions, and increased their access to healthcare. These findings may set the foundation for innovative risk-based and remote interventions to reduce the burden of CVD in this growing population of patients. [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]

• Nonmalignant blood diseases are curable by allogeneic bone marrow transplantation (BMT). • Too few patients are offered BMT due to perceived risks. • The Blood and Marrow Transplant Clinical Trials Network has prioritized diseases for clinical trial development. • Bone marrow failure is the top priority, followed by thalassemia. Nonmalignant blood diseases such as bone marrow failure disorders, immune dysregulation disorders, and hemoglobinopathies often lead to shortened life spans and poor quality of life. Many of these diseases can be cured with allogeneic hematopoietic cell transplantation, but patients are often not offered the procedure because of perceived insufficient efficacy and/or excess toxicity. In 2018, the Blood and Marrow Transplant Clinical Trials Network convened a task force to identify the most urgently needed yet feasible clinical trials with potential to improve the outcomes for patients with nonmalignant diseases. This report summarizes the task force discussions and specifies the network plans for clinical trial development for nonmalignant blood diseases. [ABSTRACT FROM AUTHOR]

• Responses are durable with ibrutinib in steroid-refractory or -dependent chronic graft-versus-host disease (cGVHD) • Ibrutinib improves quality of life in steroid-refractory or -dependent cGVHD. • Longer-term ibrutinib is safe and tolerable in steroid-refractory or -dependent cGVHD. Chronic graft-versus-host disease (cGVHD) is a life-threatening complication of allogeneic stem cell transplantation. In a Phase 1b/2, open-label study (PCYC-1129; ClinicalTrials.gov identifier NCT02195869) involving 42 patients with active cGVHD who were steroid-dependent or -refractory, the activity and safety of ibrutinib, a once-daily inhibitor of Bruton's tyrosine kinase, was demonstrated. Here we report extended follow-up for patients in this study. After a median follow-up of 26 months (range,.53 to 36.7 months), best overall response rate in the all treated population was 69% (29 of 42), with 13 patients (31%) achieving a complete response and 16 patients (38%) achieving a partial response. Sustained responses of ≥20, ≥32, and ≥44 weeks were seen in 20 (69%), 18 (62%), and 16 (55%) of the 29 responders, respectively. Of 26 patients with ≥2 involved organs, 19 (73%) showed responses in ≥2 organs. Six of 10 patients (60%) with ≥3 involved organs showed responses in ≥3 organs. Eleven of 18 patients (61%) who had sclerosis at baseline showed a sclerotic response (39% with complete response, 22% with partial response). Twenty-seven of 42 patients (64%) reached a corticosteroid dose of <.15 mg/kg/day during the study; 8 discontinued corticosteroid treatment and remained off corticosteroid at study closure. Safety findings for this updated analysis were consistent with the safety profile seen at the time of the original analysis. Common grade ≥3 adverse events (AEs) were pneumonia (n = 6), fatigue (n = 5), and diarrhea (n = 4). The onset of new grade ≥3 AEs decreased from 71% in the first year of treatment to 25% in the second year (n = 12). AEs leading to discontinuation occurred in 18 patients (43%). At a median follow-up of >2 years, ibrutinib continued to produce durable responses in patients with cGVHD who had failed previous systemic therapy. In this pretreated, high-risk population, clinically meaningful benefit and an acceptable safety profile were observed with additional follow-up for ibrutinib. These results demonstrate a substantial advance in the therapeutic management of patients with cGVHD. [ABSTRACT FROM AUTHOR]

Highlights • PepVax is an investigational cytomegalovirus (CMV) vaccine that has shown tolerability and clinical benefits in a Phase Ib trial. • Longitudinal immune monitoring of memory phenotypes was performed in enrolled patients to study the functionality and antiviral role of CMV-specific T cells. • In vaccinated hematopoietic cell transplantation recipients, PepVax elicited marked levels of differentiated effector memory pp65-specific CD8+ T cells in the absence of viremia. • The functional memory phenotype of the expanded CMV-specific T cell subsets may have been key to the favorable outcomes of the PepVax clinical trial. ABSTRACT Early cytomegalovirus (CMV) reactivation remains a significant cause of morbidity and mortality in allogeneic hematopoietic cell transplant (HCT) recipients. CMVPepVax is an investigational peptide vaccine designed to control CMV infection in HCT recipients seropositive for CMV by stimulating the expansion of T cell subsets that target the CMV tegument protein pp65. In a randomized Phase Ib pilot trial (ClinicalTrials.gov NCT01588015), two injections of CMVPepVax (at days 28 and 56 post-HCT) demonstrated safety, immunogenicity, increased relapse-free survival, and reduced CMV reactivation and use of antivirals. In the present study, we assessed the phenotypes and time courses of the pp65-specific CD8 T cell subsets that expanded in response to CMVPepVax vaccination. The functionality and antiviral role of CMV-specific T cells have been linked to immune reconstitution profiles characterized predominantly by differentiated effector memory T (TEM) subsets that have lost membrane expression of the costimulatory molecule CD28 and often reexpress the RA isoform of CD45 (TEMRA). Major histocompatibility complex class I pp65 495 - 503 multimers, as well as CD28 and CD45 memory markers, were used to detect immune reconstitution in blood specimens from HCT recipients enrolled in the Phase Ib clinical trial. Specimens from the 10 (out of 18) vaccinated patients who had adequate (≥.2%) multimer binding to allow for memory analysis showed highly differentiated TEM and TEMRA phenotypes for pp65 495-503 -specific CD8 T cells during the first 100days post-transplantation. In particular, by day 70, during the period of highest risk for CMV reactivation, combined TEM and TEMRA phenotypes constituted a median of 90% of pp65 495-503 -specific CD8 T cells in these vaccinated patients. CMV viremia was not detectable in the patients who received CMVPepVax, although their pp65 495-503 -specific CD8 T cell profiles were strikingly similar to those observed in viremic patients who did not receive the vaccine. Collectively, our findings indicate that in the absence of clinically relevant viremia, CMVPepVax reconstituted significant levels of differentiated pp65 495-503 -specific CD8 TEMs early post-HCT. Our data indicate that the rapid reconstitution of CMV-specific T cells with marked levels of effector phenotypes may have been key to the favorable outcomes of the CMVPepVax clinical trial. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

ABSTRACT The current standard of care for patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) is high-dose conditioning followed by autologous stem cell transplantation (ASCT). For some patients (ie, those with highest-risk disease, insufficient stem cell numbers after mobilization, or bone marrow involvement) allogeneic hematopoietic cell transplantation (alloHCT) offers the potential for cure. However, the majority of patients undergoing alloHCT receive reduced-intensity conditioning as a preparative regimen, and studies assessing outcomes of patients after alloHCT with myeloablative conditioning are limited. In this retrospective study, we reviewed outcomes of 22 patients with recurrent and refractory NHL who underwent alloHCT with myeloablative BEAM conditioning and received tacrolimus/sirolimus as graft-versus-host disease (GVHD) prophylaxis at City of Hope between 2005 and 2018. With a median follow-up of 2.6 years (range, 1.0 to 11.2 years), the probabilities of 2-year overall survival and event-free survival were 58.3% (95% confidence interval [CI], 35.0% to 75.8%) and 45.5% (95% CI, 24.4% to 64.3%), respectively. The cumulative incidence of grade II to IV acute GVHD was 45.5% (95% CI, 23.8% to 64.9%), with only 1 patient developing grade IV acute GVHD. However, chronic GVHD was seen in 55% of the patients (n = 12). Of the 22 eligible patients, 2 had undergone previous ASCT and 2 had undergone previous alloHCT. Both patients with previous ASCT developed severe regimen-related toxicity. Patients who underwent alloHCT with chemorefractory disease had lower survival rates, with 1-year OS and EFS of 44.4% and 33.0%, respectively. In conclusion, alloHCT with a BEAM preparative regimen and tacrolimus/sirolimus-based GVHD should be considered as an alternative option for patients with highest-risk lymphoma whose outcomes are expectedly poor after ASCT. [ABSTRACT FROM AUTHOR]

Highlights • Ruxolitinib use was associated with a reduction in prednisone dose. • The rate of infectious/bacterial infections was high and contributed to the overall mortality. • Ruxolitinib as salvage therapy is promising for chronic graft-versus-host disease refractory to steroids. Abstract Chronic graft-versus-host disease (cGVHD) continues to be a major complication after allogeneic hematopoietic cell transplantation, significantly affecting patients' quality of life. A regimen of systemic corticosteroids is considered first-line therapy but is often associated with inadequate responses and multiple side effects. In patients with refractory disease, an evidenced-based consensus is lacking as to the single best approach to managing symptoms. Ruxolitinib, a selective JAK1/2 inhibitor, has recently gained favor as a second-line approach in patients with steroid-refractory cGVHD. In this retrospective study, we evaluated the outcomes of 46 patients who received ruxolitinib for cGVHD between March 2016 and December 2017 at our institution, and evaluated ruxolitinib's impact at 6 and 12 months, based on the National Institutes of Health Severity Scale, including organ-specific responses, and mean prednisone dose. Furthermore, we present the first reported probability of ruxolitinib's treatment failure-free survival (FFS) in patients with cGVHD. After 12 months of ruxolitinib therapy, complete response, partial response, and stable disease was observed in 13% (n = 6), 30.4% (n = 14), and 10.9% (n = 5) of patients, respectively. The 1-year probability of FFS was 54.2% (95% confidence interval,.388 to.673), and ruxolitinib use was associated with a reduction in prednisone dose. In conclusion, our data, which represent the largest cohort of patients with cGVHD reported to date, support the use of ruxolitinib for cGVHD refractory to steroids and currently available salvage therapies, discontinued due to lack of response and high cost. [ABSTRACT FROM AUTHOR]

The tyrosine kinase inhibitor dasatinib is often used after allogeneic hematopoietic cell transplantation to treat minimal residual disease in Philadelphia chromosome–positive (Ph+) acute lymphoblastic leukemia (ALL). Colitis, sometimes hemorrhagic, has occasionally been described with the use of dasatinib for both chronic myeloid leukemia and Ph+ ALL. The pathogenesis of dasatinib-induced colitis is unclear but may be related to effects of dasatinib on immune function. We describe a series of 5 patients who had 7 episodes of colitis during dasatinib use. No patient had obvious large granular lymphocytosis in peripheral blood. The histopathologic and immunohistochemical features of these cases were indistinguishable from control cases of gut graft-versus-host disease (GVHD). In all patients symptoms resolved upon discontinuation of dasatinib in addition to therapy with local or low-dose systemic steroids. An additional 3 patients who developed cytomegalovirus (CMV) colitis while on dasatinib therapy were identified and studied. Dasatinib colitis may have an immune-mediated mechanism similar to GVHD, and dasatinib use may be associated with CMV colitis. Awareness of this association is important for avoiding unnecessary intensification of immunosuppression for suspected gut GVHD. [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]

Background Allogeneic hematopoietic cell transplant (allo-HCT) recipients often require substantial but variable transfusion support. Few studies have quantified their transfusion burden, or identified prognostic factors for increased transfusions to guide patient counseling or inventory management. Data on haploidentical HCT (Haplo-HCT) patients are especially scarce. Objectives To identify factors associated with increased RBC and platelet (PLT) transfusions, and provide for the first time data on a large cohort of Haplo-HCT patients. Methods We retrospectively evaluated 1803 consecutive first time adult allo-HCT patients transplanted at our center in 2011-17. Multivariate linear regression and Fine-Gray subdistribution hazards models were used to examine the associations between baseline characteristics (age, sex, disease stage, graft type, donor type, ABO compatibility and conditioning regimen) and log-transformed transfusion units in the first 30 days after HCT and time to reach transfusion independence respectively. Results The median age of the cohort was 53(18-78); 56.2% were male. Most common diagnoses were AML (38.8%), ALL (19.6%), and lymphoma (14.8%); 50.2% had advanced disease. Patients received nonmyeloablative/reduced intensity (58.9%) or myeloablative conditioning regimens (MAC, 41.1%), followed by peripheral blood stem cell (88.4%), bone marrow (6.9%) or umbilical (UC, 4.7%) HCT. Most grafts were from matched related (MRD, 38.7%) or unrelated (MUD, 49.1%) donors, and 7.6% were haploidentical. ABO incompatibility (Major 15.8%, minor 18.6%, bi-directional 8.5%) was present in 42.9% of the cases (Table 1). Most of the 1764 patients who survived 30+ days received RBC (88.2%) or PLT (97.2%) transfusions during the first 30 days, with a median of 3 (0-37) RBC and 5(0-144) apheresis PLT units. RBC and PLT transfusion independence was reached in 28 (95%CI: 26-31) and 12 (95%CI: 12-13) days respectively. Multivariate analyses showed that Haplo-HCT and UC graft were independently associated with more RBC and PLT transfusions, as were advanced disease, ABO incompatibility, older age, and MAC (P<0.001 for all variables). Prolonged PLT or RBC transfusion dependence was independently associated with Haplo-HCT, UC graft and advanced disease (P<0.001 for all three), older age (P=0.003) and ABO incompatibility (P<0.001 for RBC, P=0.008 for PLT), but not sex or conditioning regimen. Haplo-HCT patients needed fewer transfusions than UC, but more than MRD/MUD recipients; they also became transfusion-independent faster than UC, but slower than MRD/MUD recipients regardless of graft type (Table 2 & 3). Conclusions We identified patient and transplant factors strongly associated with increased transfusions in the first 30 days after allo-HCT, and quantified the transfusion burden of Haplo-HCT relative to other types of HCT. [ABSTRACT FROM AUTHOR]

Allelic variants of genes implicated in drug absorption, distribution, metabolism, and excretion (ADME) determine the pharmacokinetic variability of many medications and are increasingly recognized as important factors determining the success or failure of medical treatments. Both tacrolimus and sirolimus have narrow therapeutic ranges maintained by therapeutic drug monitoring (TDM). Using an ADME panel that covers >99% of the PharmaADME working group core list (188 single nucleotide polymorphism [SNP] and 12 copy number variant [CNV] assays in 36 pharmacogenetically relevant genes), we studied 177 patients who underwent allogeneic hematopoietic cell transplantation (HCT) using tacrolimus/sirolimus–based graft-versus-host disease (GVHD) prophylaxis. We tested for possible associations between ADME variants and tacrolimus/sirolimus drug levels, concentration/dose (C/D) ratio, and clinical endpoints, including acute GVHD. A total of 62 SNP and 6 CNV assays were evaluable after removing the variants, which were homozygous in (nearly) all samples. For sirolimus, rs2032582 (ABCB1) T-carriers versus non–T-carriers were associated with higher blood levels ( P = .01), with similar results for C/D ratio. Generalized estimating equation analysis supported these findings. For tacrolimus, rs776746 CYP3A5*3/*3 and CYP3A5*3/*1 were associated with higher blood levels than CYP3A5*1/*1 ( P = .002). By multivariable analysis, rs776746 CYP3A5*3/*3 and CYP3A5*3/*1 were independently associated with decreased acute GVHD compared with CYP3A5*1/*1 , after adjustment for conditioning, donor type, race/ethnicity, and age. We demonstrated association of specific ADME genetic polymorphisms with blood levels of tacrolimus/sirolimus, and incidence of acute GVHD after HCT, in spite of TDM and dose adjustment. A larger ongoing study will determine whether these associations have clinical utility beyond TDM. [ABSTRACT FROM AUTHOR]

We sought to determine whether differences in chronic graft-versus-host disease (GVHD) rates would lead to survival differences by comparing 2463 peripheral blood (PB) and 1713 bone marrow (BM) hematopoietic cell transplant recipients. Patients had acute leukemia, chronic myeloid leukemia (CML), or myelodysplastic syndrome, and they received myeloablative conditioning regimens and calcineurin-inhibitor GVHD prophylaxis. There were no significant differences in long-term survival after transplantation of PB and BM, except for patients in first chronic phase CML. For these patients, the 5-year rate of survival was lower after transplantation of PB compared with transplantation of BM (35% versus 56%, P = .001). Although mortality risks were higher in patients with chronic GVHD after both PB (hazard ratio [HR], 1.58; P < .001) and BM (HR 1.73; P < .001) transplantations, its effect on mortality did not differ by graft type ( P = .42). BM is the preferred graft for first chronic phase CML, whereas as either graft is suitable for other leukemias. [ABSTRACT FROM AUTHOR]

The introduction of reduced-intensity conditioning (RIC) regimens made it possible to offer allogeneic hematopoietic cell transplantation (alloHCT) to older patients with myelodysplastic syndromes (MDS). However, the relative risks and benefits of alloHCT compared with novel nontransplant therapies continue to be the source of considerable uncertainty. We will perform a prospective biologic assignment trial to compare RIC alloHCT with nontransplant therapies based on donor availability. Primary outcome is 3-year overall survival. Secondary outcomes include leukemia-free survival, quality of life, and cost-effectiveness. Four hundred patients will be enrolled over roughly 3 years. Planned subgroup analyses will evaluate key biologic questions, such as the impact of age and response to hypomethylating agents on treatment effects. Findings from this study potentially may set a new standard of care for older MDS patients who are considered candidates for alloHCT. [ABSTRACT FROM AUTHOR]

Abstract: Posttransplantation thrombotic microangiopathy (TMA) is a multifactorial complication of allogeneic hematopoietic cell transplantation (allo-HCT) whose incidence is increased with the use of a sirolimus plus tacrolimus (SIR/TAC) regimen for acute graft-versus-host disease (aGVHD) prophylaxis. We evaluated the incidence and possible risk factors for TMA in a case series of 177 patients who received allo-HCT using SIR/TAC-based GVHD prophylaxis. The patients received either a sibling donor graft (n = 82) or a matched unrelated donor graft (n = 95). Within the first 100 days post-HCT, 30 patients (17%) were diagnosed with TMA, and an additional 9 patients (5%) were classified as probable TMA cases. The median time to onset of TMA was 4.6 weeks (range, 1.6-10.6 weeks). Thirty-four patients developed both TMA and aGVHD, with the majority (81%) developing aGVHD first. Multivariate analysis identified the following factors as associated with increased risk of TMA: day 14 serum sirolimus level ≥9.9 ng/mL (hazard ratio [HR], 2.19; 95% confidence interval [CI], 1.13-4.27; P = .02), presence of previous aGVHD grade II-IV (HR, 3.04; 95% CI, 1.38-6.71; P < .01), and fully myeloablative conditioning (HR, 3.47; 95% CI, 1.60-7.53; P < .01). These risk factors for TMA suggest that when using a SIR/TAC regimen for GVHD prophylaxis, careful monitoring and adjustment of the sirolimus dosage is critical, particularly in patients with active aGVHD. [Copyright &y& Elsevier]

Abstract: The killer cell Ig-like receptor (KIR)–MHC class I pathway is an integral part of natural killer cell immunity, and its role in host protection from both cancer and infection is important. In addition, we have shown elevated KIR2DS2 and 2DS4 expression in PBMCs of patients undergoing hematopoietic cell transplantation (HCT) [1]. Since all inhibitory KIR promoters are known to be heavily methylated, the question asked here is how and when KIR2DS2 and 2DS4 promoters had changed their methylation profile in association with HCT. Genomic DNA, extracted from 20 KIR2DS2/4+ donor and recipient cells, was treated with sodium bisulfate that will modify the unmethylated cytosine into uracil. Sequencing chromatographs were examined for C/T double peak indicative of base conversion. A CpG island in KIR2DS2 promoter spans from −160 to +26 with six cytosine sites. In contrast, the KIR2DS4 promoter CpG island contains three cytosine sites. The noted increase of unmethylated sites was associated with increased KIR expression as measured by mRNA–cDNA Q-PCR. In addition, the frequency of unmethylated sites in the CpG island was increased after HCT. The mechanism through which hypomethylation occurs after HCT is not known but it suggests a linkage to NK clonal expansion during the process of NK education in response to transplant therapy or viral infection. [Copyright &y& Elsevier]

Excessive adverse events were encountered in a Phase I/II study of cyclophosphamide (CY) dose deescalation in a fludarabine-based conditioning regimen for bone marrow transplantation from unrelated donors in patients with severe aplastic anemia. All patients received fixed doses of antithymocyte globulin, fludarabine, and low-dose total body irradiation. The starting CY dose was 150 mg/kg, with deescalation to 100 mg/kg, 50 mg/kg, or 0 mg/kg. CY dose level 0 mg/kg was closed due to graft failure in 3 of 3 patients. CY dose level 150 mg/kg was closed due to excessive organ toxicity (n = 6) or viral pneumonia (n = 1), resulting in the death of 7 of 14 patients. CY dose levels 50 and 100 mg/kg remain open. Thus, CY at doses of 150 mg/kg in combination with total body irradiation (2 Gy), fludarabine (120 mg/m2), and antithymocyte globulin was associated with excessive organ toxicity. [ABSTRACT FROM AUTHOR]

Clofarabine is a novel purine nucleoside analog with immunosuppressive and antileukemia activity. We performed a phase I study of the combination of clofarabine plus melphalan as a reduced-intensity conditioning regimen for allogeneic stem cell transplantation in patients with acute myelogenous leukemia. Patients over age 18 in complete remission or with active disease (up to 50% marrow blasts) who had a matched related or unrelated donor were eligible. The conditioning regimen consisted of escalating doses of clofarabine plus melphalan, followed by allogeneic stem cell transplantation. Sixteen patients (median age, 63 years) were treated at 3 dose levels; 4 of these patients had primary induction failure, and 3 were in first relapse. One patient at dose level 2 and 1 patient at dose level 3 died of multiorgan toxicity; no other dose-limiting toxicities were seen. All other patients at both doses of clofarabine studied demonstrated complete engraftment by day 30, with a median time to absolute neutrophil count recovery of 14 days, and 16 days for platelet recovery. With a median follow-up of 17 months, only 2 patients relapsed, and 4 patients died. Clofarabine plus melphalan at dose level 2 is a well-tolerated conditioning regimen with activity in patients with advanced acute myelogenous leukemia. [ABSTRACT FROM AUTHOR]

The important role of activating killer immunoglobulin-like receptors (KIRs) in protecting against cytomegalovirus (CMV) reactivation has been described previously in patients undergoing hematopoietic cell transplantation (HCT). More specifically, the presence of multiple activating KIRs and the presence of at least KIR2DS2 and KIR2DS4 in the donor genotype identified a group of HCT patients at low risk for CMV reactivation. However, CMV infection still occurs in patients with the KIR protective genotype, and the question has been raised as to whether this is related to the lack of KIR expression. In this report, expression of the KIR2DS2 and KIR2DS4 genes, as measured by mRNA-based quantitative polymerase chain reaction in both the donor cells and the HCT recipient cells, was studied relative to CMV reactivation. In the control samples from healthy donors, the median range for KIR2DS2 and KIR2DS4 expression was low, with 35% of donors considered null-expressers. Interestingly, KIR2DS2 and KIR2DS4 expression was elevated after HCT compared with donor expression before HCT, and was significantly elevated in CMV viremic compared with CMV nonviremic HCT recipients. The CMV seropositivity of donors was not associated with activating KIR expression, and donor null expression in those with the KIR2DS2 or KIR2DS4 genotype was not predictive for CMV reactivation in the recipient. After controlling for other transplant factors, including donor type (sibling or unrelated), transplant source (bone marrow or peripheral blood stem cells), and acute GVHD grade, regression analysis of elevated KIR gene expression found an association for both KIR2DS2 and KIR2DS4, with a 7-fold increase in risk for CMV reactivation. We speculate that the elevated activating KIR expression in CMV-viremic HCT recipients is either coincidental with factors that activate CMV or is initiated by CMV or cellular processes responsive to such CMV infection reactivation. [ABSTRACT FROM AUTHOR]

Allogeneic hematopoietic cell transplantation (HCT) using reduced-intensity conditioning (RIC) regimens is a potentially curative treatment for patients (patients) with myelofibrosis (MF), as we and others have reported. Nonrelapse mortality (NRM) from graft-versus-host disease (GVHD) and other complications has limited the success of this approach. As part of an ongoing prospective research study at City of Hope, a combination of tacrolimus/sirolimus ± methotrexate (MTX) for GVHD prophylaxis has become the standard treatment for our allogeneic HCT patients. In this report, we present results for 23 consecutive patients, including extended follow up for 9 patients previously reported who received cyclosporine (CsA)/mycophenolate moffetil (MMF)±MTX, and the current series of 14 patients who received tacrolimus/sirolimus±MTX, and evaluate the impact of the GVHD prophylaxis regimen on the outcomes. Median follow-up for alive patients was 29.0 months (9.5-97.0). The estimated 2-year overall survival (OS) for the CsA/MMF cohort was 55.6% (confidence interval 36.0, 71.3), and for the tacrolimus/sirolimus cohort it was 92.9% (63.3, 98.8) (P =.047). The probability of grade III or IV acute GVHD (aGVHD) was 60% for the CsA/MMF patients, and 10% for the tacrolimus/sirolimus group (P =.0102). No significant differences were seen for grade II to IV aGVHD in the 2 groups. We conclude that the combination of tacrolimus/sirolimus±MTX for GVHD prophylaxis in the setting of RIC HCT for MF appears to reduce the incidence of severe aGVHD and NRM, and leads to improved OS compared to CSA/MMF±MTX. [Copyright &y& Elsevier]

Abstract: In the era of cytomegalovirus (CMV)-preemptive therapy, it is unclear whether CMV serostatus of donor or recipient affects outcome of allogeneic hematopoietic stem cell transplantation (HSCT) among children with leukemia. To investigate, consecutive patients aged 0-18 who underwent primary HSCT for acute leukemia in 1997-2007 (HLA-matched sibling or unrelated donor, myeloablative conditioning, unmanipulated bone marrow or peripheral blood, preemptive therapy, no CMV prophylaxis) were followed retrospectively through January 2008. Treatment failure (relapse or death) was analyzed using survival-based proportional hazards regression. Competing risks (relapse and nonrelapse mortality, NRM) were analyzed using generalized linear models of cumulative incidence-based proportional hazards. Excluding 4 (2.8%) patients lacking serostatus of donor or recipient, there were 140 subjects, of whom 50 relapsed and 24 died in remission. Pretransplant CMV seroprevalence was 55.7% in recipients, 57.1% in donors. Thirty-five (25.0%) grafts were from seronegative donor to seronegative recipient (D−/R−). On univariate analysis, D−/R− grafts were associated with shorter relapse-free survival (RFS) than other grafts (median 1.06 versus 3.15 years, P < .05). Adjusted for donor type, diagnosis, disease stage, recipient and donor age, female-to-male graft, graft source, and year, D−/R− graft was associated with relapse (hazards ratio 3.15, 95% confidence interval 1.46-6.76) and treatment failure (2.45, 1.46-4.12) but not significantly with NRM (2.00, 0.44-9.09). In the current era, children who undergo allogeneic HSCT for acute leukemia have reduced risk of relapse and superior RFS when recipient and/or donor is CMV-seropositive before transplantation. However, no net improvement in RFS would be gained from substituting seropositive unrelated for seronegative sibling donors. [Copyright &y& Elsevier]

Abstract: Cytomegalovirus (CMV) disease-related mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients has dramatically declined because of ganciclovir prophylaxis and preemptive therapeutic strategies. However, ganciclovir has not improved overall survival in randomized studies despite effectively preventing overt CMV disease. Moreover, recurrent posttransplant CMV antigenemia, associated with prolonged ganciclovir exposure, is a predictor of increased relapse of malignancy. We examined the hypothesis that ganciclovir itself may have a negative impact on immune reconstitution by testing the effect of ganciclovir on normal human lymphocytes in vitro. T-lymphocyte activation and proliferation, as measured by PHA-induced 3H-thymidine uptake, was greatly reduced at therapeutic concentrations of ganciclovir (10 μg/mL) but not for foscarnet (300 μM/L). Moreover, ganciclovir impaired bromodeoxyuridine incorporation in proliferating lymphocytes, but did not impair lymphocyte survival or induce lymphocyte apoptosis. Collectively, these results show that ganciclovir suppresses T-lymphocyte proliferation in vitro by inhibiting DNA synthesis; with implications for T-lymphocyte function following allogeneic BMT. [Copyright &y& Elsevier]

Abstract: In systemic mastocytosis with associated clonal, hematological non-mast cell lineage disease (SM-AHNMD), mast cell infiltration of the bone marrow coexists with a hematologic neoplasm, usually of myeloid origin. Activating KIT gene mutations are universally present in these neoplastic mast cells. When SM is associated with AML, the leukemic cells commonly carry the t(8;21)(q22;q22) core binding factor translocation. The precise relationship between neoplastic mast cells and the leukemic clone has remained unclear. By target FISH analysis, we demonstrate t(8;21) in the bone marrow mast cells of a patient with systemic mastocytosis associated with t(8;21) AML, thus, proving the origin of these neoplastic mast cells from the leukemic clone. We also show that after successful allogeneic hematopoietic stem cell transplantation, these neoplastic bone marrow mast cells can persist without adverse consequences and gradually decline with time. [Copyright &y& Elsevier]

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]

Since Human leukocyte antigen (HLA) and ABO blood group system are inherited independently and with up to 50% of allogeneic hematopoietic cell transplantations (HCT) are performed with donor-recipient ABO incompatibility, recipients are at increased risk for acute and delayed hemolytic reaction and delayed RBC precursors engraftment; i.e. pure RBC aplasia (PRCA). PRCA is a sever consequence of major and bi-directional ABO mismatch after alloHCT, leading to frequent transfusions, iron overload and secondary complications. Risk factors for PRCA after Major ABO incompatibility include; stem cell source, conditioning intensity, and titer of iso-agglutinins. Treatment is mostly supportive with transfusions and growth factors as well as withdrawing immunosuppressive therapy (IS). Targeting recipient immune system with high-dose steroids, DLI, and rituximab have been reported with variable results. Here we report a case series of a novel method of targeting recipient iso-agglutinins-producing B cells by Ibrutinib. We report 3 cases of PRCA refractory to conventional therapy who responded to ibrutinib, a BTK inhibitor targeting recipient B cells to allow engraftment of donor RBCs. Patient, transplant and disease characteristic including prior therapies, time to transfusion independence, and switch of blood group (BG) are summarized in Table 1. First patient's day 30 post-transplant bone marrow biopsy (BMBx) showed complete remission (CR) with full donor chimera, but BG remained O. He developed severe anemia requiring transfusions and Day 100 BMBx showed CR with markedly decreased number of erythroid progenitors. He did not respond to IS withdrawal, prednisone, rituximab or bortezomib. But BMBx 4 weeks after starting ibrutinib showed trilineage hematopoiesis. Second patient remained RBC transfusion dependent post-HCT with Day 100 biopsy showing PRCA and full donor chimera. BG remained O. He developed severe GVHD of skin and eyes after DLI and His PRCA was refractory to multiple lines of therapies but responded to ibrutinib. Third patient underwent HCT for refractory AML with MDS; Anti-A isoagglutinin level pre-HCT was high and patient underwent plasma exchange. Day 30 BMBx showed CR and full donor chimera. Day +73 BMBx showed CR with near absent erythropoiesis. PRCA was refractory to rituximab and responded to ibrutinib. All three patients with PRCA refractory to multiple lines of therapy responded to ibrutinib with median time to transfusion independence of 4 weeks and median time to BG switch of 6 weeks. All patients tolerated therapy well. Our experience at City of Hope shows that ibrutinib could offer a safe and efficacious treatment option for cases of refractory PRCA. Prospective studies are needed to assess if early therapy with ibrutinib could reduce the morbidity resulting from frequent transfusions, and GVHD complications. [ABSTRACT FROM AUTHOR]

Abstract: Reduced-intensity regimens (RIRs) are being used with increasing frequency in patients with non-Hodgkin’s lymphoma (NHL) undergoing allogeneic transplantation. The impact of dose reduction on relapse and survival has not been extensively studied. We performed a retrospective analysis of 88 patients conditioned with conventional myeloablative regimens (CMRs) (n = 48) and an RIR (n = 40) of fludarabine 125 mg/m2 and melphalan 140 mg/m2. Compared with the patients receiving CMR, those receiving RIR were older, had more often failed autologous transplantation, and had more frequently received peripheral blood and unrelated donor transplants. Graft-versus-host disease prophylaxis was provided with cyclosporine + methotrexate ± prednisone for the CMR and with cyclosporine + mycophenolate ± methotrexate for the RIR. The relapse rate was significantly lower in the patients receiving CMR than in those receiving RIR (13% vs 28%; P = .05). The 1-year transplantation-related mortality rate was 33% for CMR and 28% for RIR (P = .40). Kaplan-Meier 2-year overall survival and progression-free survival were 52% and 46% for CMR versus 53% and 40% for RIR (P = not significant). Using cumulative incidence functions based on competing risks, univariate analysis, and treatment-related prognostic factors, we found that higher treatment intensity (P = .03; relative risk [RR] = 35%) and absence of previous autologous transplantation (P = .0007; RR = 20%) were associated with a lower relapse rate. Using a Cox univariate proportional hazards model, we found that chemosensitive disease at transplantation (P = .05; RR = 57%) and absence of previous autologous transplantation (P = .002; RR = 37%) were associated with improved survival. Our observation of similar survival in the patients receiving CMR and those receiving RIR confirms that RIRs are feasible alternatives for high-risk patients with NHL; however, the data suggest that reduced treatment intensity and previous autologous transplantation are associated with increased relapse. [Copyright &y& Elsevier]

Abstract: Current treatment of chronic graft-versus-host disease (cGVHD) with prednisone (PSE) alone or with added cyclosporine or tacrolimus still has a very high failure and complication rate, and new treatment approaches are needed for both primary and salvage therapy. Mycophenolate mofetil (MMF) is an immunosuppressive agent currently in use for acute graft-versus-host disease prophylaxis. To determine whether MMF had activity in the treatment of cGVHD, we added MMF to standard cyclosporine, tacrolimus, and/or PSE as salvage/second-line (n = 24) or first-line (n = 10) therapy in 34 patients. Nine (90%) of 10 patients receiving first-line and 18 (75%) of 24 receiving second-line MMF therapy responded. Twelve (35%) patients had a complete remission, 15 (44%) had a partial remission, 5 (15%) had stable disease, and only 2 (6%) had progressive disease. Out of 30 patients receiving PSE, 22 (73%) were able to decrease PSE doses (median decrease of 50%; range, 25%–100%). With a median follow-up of 24 months (range, 6–28 months), 29 (85%) patients are alive. Three patients had to discontinue MMF because of abdominal cramps within 3 months of starting treatment. These data suggest that MMF is an active, well-tolerated agent in the treatment of cGVHD and may have a beneficial effect on the survival of patients with this complication. [Copyright &y& Elsevier]

Historically, outcomes of adult patients (pts) with ALL who fail to enter remission with standard induction chemotherapy are very poor. Blinatumomab, a bispecific CD3/CD19 antibody, has shown remarkable activity in relapsed/refractory (r/r) ALL. While allogeneic HCT is the recommended consolidation therapy for r/r ALL pts who respond to salvage therapy, HCT and toxicity outcomes for those who received blinatumomab salvage and HCT remains largely unknown. A retrospective review of r/r ALL pts medical records, who received blinatumomab salvage therapy from 2012 to 2018 at our institution was obtained. Only pts who responded to blinatumomab and underwent HCT were included (n=29). Kaplan-Meier curves and the log-rank test were used to evaluate the overall survival (OS) and progression-free survival (PFS). Cumulative incidence (CI) curves and the Gray test were used to examine the differences in relapse rates and non-relapse mortality (NRM). The median age at the time of HCT was 29 years (range: 19-65), and 8 pts (28%) were over 50 years old. HCT was done in complete remission- (CR)-1 (n=14, 48%) or ≥CR-2, with 2pts receiving blinatumomab salvage after relapse from a prior HCT. Pts received transplant from a matched sibling (n=11), matched unrelated (n= 12), haploidentical donor (n=5) or double umbilical cord blood (n=1) after myeloablative (n=20, including TBI+VP16, n=15) or reduced intensity (n=9) conditioning. The graft source was PBSCs in 25 pts (86.2%). Graft-versus-host disease (GVHD) prophylaxis was tacrolimus/sirolimus-based (n=19, 66%), and post-HCT cyclophosphamide (n=5, 17%) for haploidentical transplants. At the time of salvage therapy initiation, pts had either gross residual (n=22) or minimal residual disease (MRD+) (n=7). Negative MRD remission status was achieved prior to HCT in 15 pts, including those who were MRD+ before blinatumomab salvage. With a median follow up of 21.7 months (mo) (range: 1.1-55.7) for all pts and 6.4 mo for surviving pts, the 1-year OS and PFS were 72.8% (95% CI: 48.5-87.0) and 63.0% (95% CI: 38.8-79.8), respectively (Fig 1). Causes of death post-HCT were GVHD (n=3); NRM (n=4; 3 sepsis and 1 regimen related toxicity) and relapse (n=3). The CI of relapse at 1 and 2 years were 24.9% (95% CI: 8.6-45.3) and 45.9%, (95% CI: 20.3-68.3), respectively. NRM at 100 days was 6.9% (95% CI: 1.2-20.0) and at 12 mo was 12.1% (95% CI: 2.7-29.0). The incidence of grades 3-4 acute GVHD and extensive chronic GVHD at 24 mo were 25.0% (95% CI: 8.7-45.5) and 38.8% (95% CI: 14.2-63.1), respectively. No cases of veno-occlusive disease post-HCT were reported. We present here, for the 1st time, detailed data showing the tolerability and efficacy of HCT following salvage therapy with blinatumomab. No unexpected toxicities were noted post-HCT and the study showed encouraging 1-year OS and PFS with. Longer-term follow-up is ongoing for these patients. [ABSTRACT FROM AUTHOR]

Identification of anti-apoptotic properties of the Bcl2 protein has offered novel treatment options in many malignancies including AML. Venetoclax, a Bcl2 inhibitor, has shown promising results as upfront therapy in elderly patients (pts) and relapse/refractory (R/R) AML, when combined with hypomethylating agents (HMA). Yet, due to the high relapse risk, allogenic HCT remains as the only curative option for these high risk populations. To date, outcomes of HCT after prior therapy with Venetoclax + HMA have not been described. Also, as Venetoclax induces aplasia of antigen presenting cells expressing Bcl2, we hypothesized that pre-HCT treatment with venetoclax may be associated with a lower risk for GvHD. We retrospectively analyzed 26 consecutive AML pts who underwent HCT at our institution from 2016 to 2018 with final line of systemic therapy of venetoclax + HMA. Pts were not eligible for upfront standard induction chemotherapy (n=8) or had R/R disease (n=18). Fifteen pts received ≥2 lines of therapy and 3 had previous HCT. CR/CRi was achieved in 62% (n=16), of which 3 pts had minimal residual disease and the rest (n=10) had persistent disease prior to HCT. Donors were matched related (n=8), matched unrelated (n=16), or haploidentical (n=2). Conditioning regimen was myeloablative (38.5%) or reduced intensity (61.5%). Most pts (n=24, 92.3%) received PBMCs as the graft source. Tacrolimus/Sirolimus (Tac/Sir) was administered in most pts (n=20, 77%) for GvHD prophylaxis. Descriptive statistics were used for baseline characteristics. Kaplan-Meier and cumulative incidence curves were constructed for overall survival (OS), progression-free survival (PFS), relapse, none-relapse mortality (NRM), and aGvHD. Median age at the time of HCT was 59 years (range: 18-73). Median time to neutrophil and platelet engraftment were 17 days (range: 14-20) and 20 days (range: 16-61), respectively. With a median follow up of 4.5 months (range: 1.4-18.6), 6 months relapse rate was 12% (95% CI: 0.16-0.54) and 100 day NRM was 4% (95% CI: 0.02-0.34). Grade II-IV aGvHD at 100 days was noted in 34% (95% CI: 0.15-0.51). One-year OS and PFS for all pts were 72% (95% CI: 0.43-0.88) and 40% (95% CI: 0.16-0.63), respectively. For patients in CR at the time of HCT, 1-year OS was 80% (95%CI: 37-95) and PFS was 38% (95%CI: 0.08-0.69) (Fig 1). Only one patient who had been treated with three lines of systemic therapy prior to HCT experienced veno-occlusive disease. Thus, administration of Venetoclax-based salvage regimen as a bridge to HCT is safe with no added immediate toxicities post-HCT. Our early outcome data are promising for this otherwise high-risk population. Our data also justify further studies on the role and impact of Venetoclax and its anti-Bcl2 properties as a component of the conditioning regimen or as post-HCT maintenance. [ABSTRACT FROM AUTHOR]

Chronic GVHD remains as the major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Systemic corticosteroids are the first line of therapy, but outcomes are poor in steroid refractory (SR) patients. Previous reports show that in SR patients, IL-2 therapy results in partial response (PR) associated with increase in regulatory T cells (Tregs). ECP has been used for cGVHD with skin response rates of 40-100%. Based on non-overlapping toxicities and, we prospectively studied a combination of low dose IL-2 + ECP to treat SR-cGVHD. Patients with SR-cGVHD, were treated with low dose IL-2 (1 × 106 U/m2, daily) + ECP for 12 weeks. IL-2 was provided by Prometheus Laboratories. ECP was administered 2 times/week for 4 weeks followed by 2 treatments every 2 weeks for the next 8 weeks. The NIH consensus criteria was used to assess cGVHD severity. PBMC and plasma samples were banked at baseline and on 3-week intervals to assess regulatory T cell (Tregs) and reactive oxygen species (ROS). Of the 12 consented patients, 9 completed the study (2 were not treated due to rapid disease progression before enrollment and 1 died from sepsis at week 11). All enrolled patients (n=10) had scleroderma as the predominant cGVHD manifestation. Median age was 45.6 years (range: 23-66). Median prior lines of therapy were 4.2(range 3-6), 5 patients had prior exposure to ruxolitinib and 4 were on ECP at the enrollment. Donors were fully matched unrelated (n=8), matched sibling (n=1) or mismatched unrelated (n=1). Conditioning regimen was myeloablative (n=5) or reduced intensity (n=4). GVHD prophylaxis was tacrolimus/Sirolimus (tac/sir) (n=6), tac/methotrexate (MTX) (n=2), or Tac/sir/MTX (n=1). Of the 10 enrolled patients, 9 responded to IL-2 + ECP combination (all classified as PR). A 37% dose reduction in steroid dose was noted among 7 patients. The remaining 3 patients were on stable steroid dose at end of study. Only 1 patient had progressive cGVHD in form of scleroderma. ECP+IL-2 therapy was well tolerated with no drug related serious adverse events (SAE). Grade 3-4 AEs included grade 3 metabolic and nutrition (n=8), grade 3 anemia (n=3), and grade 4 atrial flutter (n=1). Infectious complications were noted in 3 patients (one grade 4 [sepsis]). There was a robust increase in Tregs from the baseline mean of 0.755% (range 0.08-1.88) to end of treatment 6.999% (range 0.78-17.13) [p=0.02] Fig 1. Increment in Tregs was seen in patients who were on ECP therapy prior to enrollment (n=4) and in one patient who progressed while on therapy. No correlation was found between the treatment response and ROS levels. In conclusion, the combination of ECP +IL-2 is well tolerated in patients with SR-cGVHD with no apparent increase in infectious complications or other toxicities. Clinical response correlates with a robust increase in Tregs, but no correlation was found with ROS levels. [ABSTRACT FROM AUTHOR]

Haploidentical (Haplo) HCT using post-transplantation cyclophosphamide (PT-Cy) has improved donor availability. However, a matched sibling donor (MSD) is still considered the optimal donor. Using the CIBMTR database, we compared outcomes after MSD HCT vs. PT-Cy-based Haplo-HCT in AML patients in CR1. Data from 1,205 adult CR1 AML patients (PT-Cy-based Haplo-HCT: 336, MSD with calcineurin inhibitor-based GVHD prophylaxis: 869) (2008-2015) were analyzed. The Haplo group included more reduced-intensity conditioning (65% vs. 30%) and bone marrow grafts (62% vs. 7%), consistent with current practice (Table 1). In univariate analysis, the Haplo group had less chronic GVHD (26 [21-31]% vs. 56 [53-60]% at 3 years, p<0.001), lower OS (48 [42-54]% vs. 55 [52-59]% at 3 years, p=0.03), and a trend for higher NRM (19 [15-24]% vs. 14 [12-17]% at 3 years, p=0.06), but similar grade II-IV acute GVHD (p=0.98), relapse (p=0.90), and LFS (p=0.11). In multivariable analysis (Figure 1), Haplo vs. MSD groups were not different in OS (p=0.15), LFS (p=0.50), or grade II-IV acute GVHD (p=0.98). However, the Haplo group had a lower rate of chronic GVHD (HR [95%CI]: 0.38 [0.30-0.48], p<0.001). Results of subgroup analyses by era or conditioning intensity were consistent with the main analysis. Our results suggest similar outcomes after current standard practices of PT-Cy-based Haplo-HCT using mostly bone marrow vs. MSD HCT using mostly peripheral blood, except for less cGVHD after Haplo-HCT. Although the groups were balanced for many important variables, the tight relationship of donor type with graft source and conditioning intensity may have influenced our findings. [ABSTRACT FROM AUTHOR]