Dose-Adjusted EPOCH Plus Inotuzumab Ozogamicin in Adults With Relapsed or Refractory B-Cell ALL: A Phase 1 Dose-Escalation Trial.

Importance: Options for adults with relapsed or refractory B-cell acute lymphoblastic leukemia or lymphoma (B-ALL) are limited, and new approaches are needed. Inotuzumab ozogamicin (InO) has been combined with low-intensity chemotherapy, with modest improvements over historical controls, and dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH) treatment is safe and active for newly diagnosed ALL. Objective: To assess the safety and clinical activity of DA-EPOCH and InO in adults with relapsed or refractory B-ALL. Design, Setting, and Participants: This single-center, single-arm, nonrandomized, phase 1 dose-escalation trial included adults with relapsed or refractory CD22+ B-ALL and was conducted between September 2019 and November 2022. At least 5% blood or marrow blasts or measurable extramedullary disease (EMD) was required for enrollment. Interventions: DA-EPOCH was given on days 1 to 5, while InO was given on day 8 and day 15 of a 28-day cycle. Three dose levels were studied using a bayesian optimal interval design. Main Outcomes and Measures: The primary outcome was the maximum tolerated dose of InO when combined with DA-EPOCH, defined as the highest dose level that produced a rate of dose-limiting toxicity below 33%. Secondary objectives included response rates, survival estimates, and descriptions of toxic effects. Results: A total of 24 participants were screened and enrolled (median age, 46 [range, 28-76] years; 15 [62%] male). The median number of lines of prior therapy was 3 (range, 1-12). Three of 11 participants (27%) treated at the highest dose level (InO, 0.6 mg/m2, on day 8 and day 15) experienced dose-limiting toxicity, making this the maximum tolerated dose. No deaths occurred during the study, and only 1 patient (4%; 95% CI, 0.1%-21%) developed sinusoidal obstructive syndrome after poststudy allograft. The morphologic complete response rate was 84% (95% CI, 60%-97%), 88% (95% CI, 62%-98%) of which was measurable residual disease negative by flow cytometry. Five of 6 participants with EMD experienced treatment response. The overall response rate was 83% (95% CI, 63%-95%). Median overall survival, duration of response, and event-free survival were 17.0 (95% CI, 8.4-not reached), 15.0 (95% CI, 6.7-not reached), and 9.6 (95% CI, 4.5-not reached) months, respectively. Conclusions: In this study, adding InO to DA-EPOCH in adults with relapsed or refractory B-ALL was feasible, with high response rates and sinusoidal obstructive syndrome occurring rarely in a heavily pretreated population. Many patients were able to proceed to poststudy consolidative allogeneic hematopoietic cell transplant and/or chimeric antigen receptor T-cell therapy. Further investigation of this combination is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT03991884.

HA-1-targeted T cell receptor (TCR) T cell therapy for recurrent leukemia after hematopoietic stem cell transplantation.

Relapse is the leading cause of death after allogeneic hematopoietic stem cell transplantation (HCT) for leukemia. T cells engineered by gene transfer to express T cell receptors (TCR; TCR-T) specific for hematopoietic-restricted minor histocompatibility (H) antigens may provide a potent selective anti-leukemic effect post-HCT. We conducted a phase I clinical trial employing a novel TCR-T product targeting the minor H antigen HA-1 to treat or consolidate treatment of persistent or recurrent leukemia and myeloid neoplasms. The primary objective was to evaluate the feasibility and safety of administration of HA-1 TCR-T post-HCT. CD8+ and CD4+ T cells expressing the HA-1 TCR and a CD8-co-receptor were successfully manufactured from HA-1 disparate HCT donors. One or more infusions of HA-1 TCR-T following lymphodepleting chemotherapy were administered to nine HCT recipients who had developed disease recurrence post-HCT. TCR-T cells expanded and persisted in vivo after adoptive transfer. No dose-limiting toxicities occurred. Although the study was not designed to assess efficacy, four patients achieved or maintained complete remissions following lymphodepletion and HA-1 TCR-T, with one ongoing at >2 years. Single-cell RNA sequencing of relapsing/progressive leukemia after TCR-T therapy identified upregulated molecules associated with T cell dysfunction or cancer cell survival. HA-1 TCR-T therapy appears feasible and safe and shows preliminary signals of efficacy. This clinical trial is registered at clinicaltrials.gov as NCT03326921.

Targeted Radiation Delivery before Haploidentical HCT for High-risk Leukemia or MDS Patients Yields Long-term Survivors.

PURPOSE: Hematopoietic cell transplantation (HCT) has curative potential for myeloid malignancies, though many patients cannot tolerate myeloablative conditioning with high-dose chemotherapy alone or with total-body irradiation (TBI). Here we report long-term outcomes from a phase I/II study using iodine-131 (131I)-anti-CD45 antibody BC8 combined with nonmyeloablative conditioning prior to HLA-haploidentical HCT in adults with high-risk relapsed/ refractory acute myeloid or lymphoid leukemia (AML or ALL), or myelodysplastic syndrome (MDS; ClinicalTrials.gov, NCT00589316). PATIENTS AND METHODS: Patients received a tracer diagnostic dose before a therapeutic infusion of 131I-anti-CD45 to deliver escalating doses (12-26 Gy) to the dose-limiting organ. Patients subsequently received fludarabine, cyclophosphamide (CY), and 2 Gy TBI conditioning before haploidentical marrow HCT. GVHD prophylaxis was posttransplant CY plus tacrolimus and mycophenolate mofetil. RESULTS: Twenty-five patients (20 with AML, 4 ALL and 1 high-risk MDS) were treated; 8 had ≥ 5% blasts by morphology (range 9%-20%), and 7 had previously failed HCT. All 25 patients achieved a morphologic remission 28 days after HCT, with only 2 patients showing minimal residual disease (0.002-1.8%) by flow cytometry. Median time to engraftment was 15 days for neutrophils and 23 days for platelets. Point estimates for overall survival and progression-free survival were 40% and 32% at 1 year, and 24% at 2 years, respectively. Point estimates of relapse and nonrelapse mortality at 1 year were 56% and 12%, respectively. CONCLUSIONS: 131I-anti-CD45 radioimmunotherapy prior to haploidentical HCT is feasible and can be curative in some patients, including those with disease, without additional toxicity.

Dental evaluation and clearance prior to allogeneic hematopoietic cell transplantation.

INTRODUCTION: Dental examination and stabilization are performed prior to allogeneic hematopoietic cell transplantation to decrease infection risk during neutropenia. Burden of dental disease and treatment need is not well characterized in this population. OBJECTIVES: This report describes the dental status of a cohort of patients within the Chronic Graft-versus-Host Disease Consortium and treatment rendered prior to transplant. METHODS: The cohort included 486 subjects (Fred Hutchinson: n = 245; Dana-Farber: n = 241). Both centers have institutional-based dental clearance programs. Data were retrospectively abstracted from medical records by calibrated oral health specialists. RESULTS: The median age at transplant was 55.9 years, 62.1% were male, and 88% were white. Thirteen patients were edentulous (2.7%). The mean teeth among dentate patients before clearance was 26.0 (SD, 4.6). Dental findings included untreated caries (31.2%), restorations (91.6%), endodontically treated teeth (48.1%), and dental implants (5.7%). Pretransplant procedures during clearance included endodontic therapy (3.6%; mean = 0.1 teeth), restorations (25.1%; mean = 0.7), dental prophylaxis (59.2%), scaling/root planing (5.1%), and extraction (13.2%; mean = 0.3). The mean teeth after clearance was 25.6 (SD, 5.0). CONCLUSIONS: Retrospective analysis of pre-AlloHCT dental data in subjects at two large transplant centers identified low levels of dental need. Findings suggest high access to care.

Acute kidney injury and chronic kidney disease in umbilical cord blood transplant recipients.

Introduction: Acute kidney injury (AKI) is a frequent early complication post hematopoietic stem cell transplant (HSCT), associated with high morbidity and mortality. Cord blood transplant (CBT) recipients are potentially exposed to more nephrotoxic insults, compared to patients undergoing HSCT from other donor sources. We aimed to identify risk factors for AKI in patients undergoing CBT. We also aimed to identify the impact of AKI on chronic kidney disease (CKD) and survival outcomes by one-year post-CBT. Methods: Adults and children who underwent a first CBT at our Institution were retrospectively evaluated. AKI was staged according to Kidney Disease Improving Global Outcomes (KDIGO) definitions. Cox regression models were used to estimate the association of demographic factors and post-CBT parameters with the cause-specific hazard of AKI. Results: We identified 276 patients. Median age was 32 years, 28% (77/276) were children (<18 years) and 129 (47%) were white. A myeloablative conditioning regimen was administered to 243 patients (88%) and 248 (90%) received cyclosporine for GVHD prophylaxis. One-hundred and eighty-six patients (67%) developed AKI by day 60 post-transplant, with 72 (26%) developing severe AKI (stage 2 and 3). In a multivariable analysis, each increase in bilirubin level of 1 mg/dL was associated with a 23% increase in the risk of severe AKI (adjusted HR 1.23, 95% CI 1.13 - 1.34, p<.0001). Conversely, systemic steroid administration appeared to be protective of severe AKI (unadjusted HR 0.36, 95% CI 0.18 - 0.72, p=.004) in a univariate model . Two-hundred-forty-seven patients were evaluable at the one-year time point. Among those, 100 patients (40%) developed CKD one-year post-CBT. Severe AKI was associated with a higher hazard of non-relapse mortality (adjusted HR=3.26, 95% CI 1.65-6.45, p=.001) and overall mortality (adjusted HR=2.28, 95% CI 1.22-4.27, p=.01). Discussion: AKI is a frequent complication after CBT and is associated with worse outcomes. Questions remain as to the mechanism of the protective role of steroids on kidney function in the setting of CBT.

Impact of GVHD prophylaxis on CMV reactivation and disease after HLA-matched peripheral blood stem cell transplantation.

The kinetics of early and late cytomegalovirus (CMV) reactivation after hematopoietic cell transplantation using various methods of graft-versus-host-disease (GVHD) prophylaxis are poorly defined. We retrospectively compared CMV reactivation and disease among 780 seropositive patients given HLA-matched peripheral blood stem cell (PBSC) grafts and calcineurin inhibitor plus posttransplantation cyclophosphamide (PTCy; n = 44), mycophenolate mofetil (MMF; n = 414), or methotrexate (MTX; n = 322). Transplantation occurred between 2007 and 2018; CMV monitoring/management followed uniform standard practice. Hazards of CMV reactivation at various thresholds were compared. Spline curves were fit over average daily viral load and areas under the curve (AUC) within 1 year were calculated. PTCy and MMF were associated with an increased risk of early (day ≤100) CMV reactivation ≥250 IU/mL after multivariate adjustment. The viral load AUC at 1 year was highest with MMF (mean difference = 0.125 units vs MTX group) and similar between PTCy and MTX (mean difference = 0.016 units vs MTX group). CMV disease risk was similar across groups. There was no interaction between GVHD prophylaxis and CMV reactivation on chronic GVHD risk. Despite PTCy-associated increased risk of early CMV reactivation, the CMV disease risk by 1 year was low in HLA-matched PBSC transplant recipients. In contrast, MMF was associated with higher overall CMV viral burden in the 1 year posttransplant. Although different mechanisms of immunosuppressive agents may affect CMV reactivation risk, effective prevention of GVHD may reduce corticosteroid exposure and mitigate infection risk over time.

An 8-year pragmatic observation evaluation of the benefits of allogeneic HCT in older and medically infirm patients with AML.

We designed a prospective, observational study enrolling patients presenting for treatment of acute myeloid leukemia (AML) at 13 institutions to analyze associations between hematopoietic cell transplantation (HCT) and survival, quality of life (QOL), and function in: the entire cohort, those aged ≥65 years, those with high comorbidity burden, intermediate cytogenetic risk, adverse cytogenetic risk, and first complete remission with or without measurable residual disease. Patient were assessed 8 times over 2 years. Time-dependent regression models were used. Among 692 patients that were evaluable, 46% received HCT with a 2-year survival of 58%. In unadjusted models, HCT was associated with reduced risks of mortality most of the subgroups. However, after accounting for covariates associated with increased mortality (age, comorbidity burden, disease risks, frailty, impaired QOL, depression, and impaired function), the associations between HCT and longer survival disappeared in most subgroups. Although function, social life, performance status, and depressive symptoms were better for those selected for HCT, these health advantages were lost after receiving HCT. Recipients and nonrecipients of HCT similarly ranked and expected cure as main goal of therapy, whereas physicians had greater expectations for cure than the former. Accounting for health impairments negates survival benefits from HCT for AML, suggesting that the unadjusted observed benefit is mostly owing to selection of the healthier candidates. Considering patients' overall expectations of cure but also the QOL burdens of HCT motivate the need for randomized trials to identify the best candidates for HCT. This trial was registered at www.clinicaltrials.gov as #NCT01929408.

Efficacy, safety, and molecular response predictors of oral ixazomib and short-course rituximab in untreated iNHL.

Patients with indolent B-cell non-Hodgkin lymphoma (iNHL) generally require treatment but experience normal survival, emphasizing the need for simpler, safer therapies. Proteasome inhibitors target aberrant signaling pathways within iNHL and have manageable toxicities. We evaluated the oral proteasome inhibitor ixazomib as initial monotherapy, and combined with rituximab, for first-line treatment of iNHL. Treatment-naïve patients with iNHL needing therapy received oral ixazomib 4 mg weekly until progressive disease or unacceptable adverse events. A 4-week course of rituximab was added during month 7. The primary end point was overall response rate (ORR) during the ixazomib monotherapy window. Correlations included gene expression profiling and response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Thirty-three patients with follicular lymphoma (FL) (n = 20), marginal zone lymphoma (n = 7), and other iNHL were treated with a median follow-up of 30.3 months. During the 6-month ixazomib window, the ORR was 24%, including 35% in FL. The best ORR over the entire study period was 52% overall and 65% in FL; complete response was achieved in 33% and 45%, respectively. The median duration of response was 25.8 months (range, 0-49.7), and the 24-month progression-free and overall survival rates were 51% (95% confidence interval [CI], 32-67) and 91% (95% CI, 74-97), respectively. Ixazomib was well tolerated. Baseline downregulation of proteasome genes, PSMB9 (P = .03) and PSMB8 (P = .007), were associated with response. All evaluated patients generated anti-S antibodies to SARS-CoV-2 vaccination, with a median of 254.9 binding arbitrary unit per mL. Ixazomib demonstrated efficacy alone and with short-course rituximab in untreated iNHL while exhibiting favorable toxicity, convenience, and retention of the B-cell immune response. This trial is registered at www.clinicaltrials.gov as NCT02339922.

Diminished humoral and cellular responses to SARS-CoV-2 vaccines in patients with chronic lymphocytic leukemia.

Previous studies have demonstrated low rates of seroconversion to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in patients with chronic lymphocytic leukemia (CLL). In this national collaboration of 11 cancer centers in the United States, we aimed to further characterize and understand vaccine-induced immune responses, including T-cell responses, and the impact of CLL therapeutics (#NCT04852822). Eligible patients were enrolled in 2 cohorts (1) at the time of initial vaccination and (2) at the time of booster vaccination. The serologic response rates (anti-S) from 210 patients in the initial vaccination cohort and 117 in the booster vaccination cohort were 56% (95% confidence interval [CI], 50-63) and 68% (95% CI, 60-77), respectively. Compared with patients not on therapy, those receiving B-cell-directed therapy were less likely to seroconvert (odds ratio [OR], 0.27; 95% CI, 0.15-0.49). Persistence of response was observed at 6 months; anti-S titers increased with the administration of booster vaccinations. In the initial vaccination cohort, positive correlations were observed between the quantitative serologic response and CD4 T-cell response for the Wuhan variant and, to a lesser degree, for the Omicron variant (Spearman P = 0.45 Wuhan; P = 0.25 Omicron). In the booster vaccination cohort, positive correlations were observed between serologic responses and CD4 T-cell responses for both variants (P = 0.58 Wuhan; P = 0.57 Omicron) and to a lesser degree for CD8 T-cell responses (P = 0.33 Wuhan; P = 0.22 Omicron). Although no deaths from coronavirus disease 2019 (COVID-19) have been reported after booster vaccinations, patients should use caution as newer variants emerge and escape vaccine-induced immunity. This trial was registered at www.clinicaltrials.gov as #NCT04852822.

Immune Checkpoint Inhibitor Use in Solid Organ Transplant Recipients: A Systematic Review.

Chronic immunosuppression in solid organ transplant recipients (SOTRs) leads to an increased risk of a wide variety of cancers. Immune checkpoint inhibitor (ICI) therapy is indicated for many of these; however, the risks and benefits of ICI use in the SOTR population have not been well characterized. We performed a systematic literature review identifying 119 reported cases of ICI use among SOTRs. Treatments used included PD-1 inhibition (75.6%), CTLA-4 inhibition (12.6%), PD-L1 inhibition (1.7%), and combination and/or sequential ICI therapy (10.1%). The most common cancers included cutaneous melanoma (35.3%), hepatocellular carcinoma (22.7%), and cutaneous squamous cell carcinoma (18.5%). The overall objective response rate (ORR) was 34.5%, with a median duration of response of 8.0 months. Ongoing response was seen in 21.0%. Cutaneous squamous cell carcinoma had significantly better ORR compared with other cancer types (68.2% vs 26.8%; odds ratio [OR], 5.85; P =.0006). Factors associated with improved ORR included increasing time from transplant to ICI (OR, 1.09; P =.008) and preemptive reduction in intensity of the graft maintenance immunosuppressive regimen (50.0% vs 18.5%; OR, 4.40; P =.0088). Rejection occurred in 41.2%, graft failure in 23.5%, and immune-related adverse events in 18.5%. Factors significantly associated with allograft rejection included allograft PD-L1 positivity (100% vs 0%; P<.0001) and absence of tacrolimus in the immunosuppressive regimen (48.7% vs 25.6%; OR, 0.36; P =.019). The most common cause of death was progressive malignancy (64.0%), followed by graft failure (24.0%). Our analysis provides current benchmark data to help inform management of SOTRs with advanced cancers that are reflected by our patient cohort. Biomarker development, more robust datasets, and prospective study of concomitant immunosuppression management may help refine decision-making in this complex scenario in the future. Close coordination of care between the medical oncologist and transplant specialist is encouraged to help optimize treatment outcomes.

HLA-DQ heterodimers in hematopoietic cell transplantation.

HLA-DQ heterodimers increase the susceptibility to autoimmune diseases, but their role in hematopoietic cell transplantation is unknown. We tested the hypothesis that outcome after HLA-matched and HLA-DQ-mismatched hematopoietic cell transplantation is influenced by HLA-DQ heterodimers. Heterodimers were defined in 5164 HLA-matched and 520 HLA-DQ-mismatched patients and their transplant donors according to well-established crystallographic criteria. Group 1 (G1) heterodimers are any DQA1*02/03/04/05/06α paired with any DQB1*02/03/04ß. Group 2 (G2) heterodimers are DQA1*01α paired with any DQB1*05/06ß. Multivariable models identified significantly higher relapse risk in G1G2 and G2G2 compared with G1G1 HLA-matched patients with malignant disease; risk increased with an increasing number of G2 molecules. In HLA-DQ-mismatched transplantation for malignant diseases, matching or mismatching for G2 increased relapse risk. G2 lowered disease-free survival after both HLA-matched and HLA-DQ-mismatched transplantation. A paradigm based on HLA-DQ heterodimers provides a functional definition of the hematopoietic cell transplantation barrier and a means to lower risks for future patients.

Prediction of outcomes after second-line treatment for acute graft-versus-host disease.

Acute graft-versus-host disease (GVHD) requiring second-line treatment represents a highly morbid complication of allogenic hematopoietic cell transplantation (HCT). Recent studies have defined short-term outcomes after second-line treatment for acute GVHD, but longer-term outcomes have not been well defined. We examined overall survival (OS) and failure-free-survival (FFS) of 216 patient who had HCT who received second-line treatment for acute GVHD. Failure time for FFS was defined as the earliest of death, relapse, or implementation of third-line treatment. Multivariable Cox regression was used to identify risk factors for mortality and failure, and predictive models were derived for 6- and 12-month mortality. Point estimates of OS at 6 and 12 months were 59% (95% confidence interval [CI], 52-65) and 52% (95% CI, 45-68), respectively. Point estimates of FFS at 6 and 12 months were 42% (95% CI, 35-48) and 37% (95% CI, 31-43), respectively. Predictive models for both end points included serum albumin and total bilirubin concentrations at the onset of second-line treatment, patient age at onset of second-line therapy, and a combination of abdominal pain/stage 4 gut involvement. Optimism-corrected areas under the receiver-operator characteristic curve and Brier scores were 77.4 and 0.169 for 6-month mortality, respectively, and 80.0 and 0.169 for 12-month mortality. We identify risk factors associated with mortality and failure after second-line treatment of acute GVHD, provide historical benchmarks for assessment of FFS and OS in other studies, and propose predictive models for 6- and 12-month mortality that could be used to generate population-specific benchmarks.

High-Throughput Drug Screening and Multi-Omic Analysis to Guide Individualized Treatment for Multiple Myeloma.

Multiple myeloma (MM) is a genetically heterogeneous malignancy characterized by variable treatment responses. Although numerous drugs have been approved in recent years, the ability to predict treatment response and tailor individual therapy is limited by the absence of robust predictive biomarkers. The goal of this clinical trial was to use ex vivo, high-throughput screening (HTS) of 170 compounds to predict response among patients with relapsed or refractory MM and inform the next treatment decisions. Additionally, we integrated HTS with multi-omic analysis to uncover novel associations between in vitro drug sensitivity and gene expression and mutation profiles. MATERIALS AND METHODS: Twenty-five patients with relapsed or refractory MM underwent a screening bone marrow or soft tissue biopsy. Sixteen patients were found to have sufficient plasma cells for HTS. Targeted next-generation sequencing was performed on plasma cell-free DNA from all patients who underwent HTS. RNA and whole-exome sequencing of bone marrow plasma cells were performed on eight and seven patients, respectively. RESULTS: Results of HTS testing were made available to treating physicians within a median of 5 days from the biopsy. An actionable treatment result was identified in all 16 patients examined. Among the 13 patients who received assay-guided therapy, 92% achieved stable disease or better. The expression of 105 genes and mutations in 12 genes correlated with in vitro cytotoxicity. CONCLUSION: In patients with relapsed or refractory MM, we demonstrate the feasibility of ex vivo drug sensitivity testing on isolated plasma cells from patient bone marrow biopsies or extramedullary plasmacytomas to inform the next line of therapy.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: III. The 2020 Treatment of Chronic GVHD Report.

Positive results from recent clinical trials have significantly expanded current therapeutic options for patients with chronic graft-versus-host disease (GVHD). However, new insights into the associations between clinical characteristics of chronic GVHD, pathophysiologic mechanisms of disease, and the clinical and biological effects of novel therapeutic agents are required to allow for a more individualized approach to treatment. The current report is focused on setting research priorities and direction in the treatment of chronic GVHD. Detailed correlative scientific studies should be conducted in the context of clinical trials to evaluate associations between clinical outcomes and the biological effect of systemic therapeutics. For patients who require systemic therapy but not urgent initiation of glucocorticoids, clinical trials for initial systemic treatment of chronic GVHD should investigate novel agents as monotherapy without concurrently starting glucocorticoids, to avoid confounding biological, pathological, and clinical assessments. Clinical trials for treatment-refractory disease should specifically target patients with incomplete or suboptimal responses to most recent therapy who are early in their disease course. Close collaboration between academic medical centers, medical societies, and industry is needed to support an individualized, biology-based strategic approach to chronic GVHD therapy.

Relevance of Plasma Matrix Metalloproteinase-9 for Bronchiolitis Obliterans Syndrome after Allogeneic Hematopoietic Cell Transplantation.

Bronchiolitis obliterans syndrome (BOS) is a highly morbid form of chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). Several plasma proteins have been identified as biomarkers for BOS after lung transplantation. The relevance of these biomarkers in BOS patients after allogeneic HCT has not been examined. We hypothesized that biomarkers associated with BOS after lung transplantation are also associated with BOS after allogeneic HCT. We tested plasma samples from 33 adult HCT patients who participated in a phase II multicenter study of fluticasone, azithromycin, and montelukast (FAM) treatment for new-onset BOS (NCT01307462), and matched control samples of HCT patients who had non-BOS chronic GVHD (n = 31) and those who never experienced chronic GVHD (n = 29) (NCT00637689 and NCT01902576). Candidate biomarkers included matrix metalloproteinase-9 (MMP-9), MMP-3, and chitinase-3-like-1 glycoprotein (YKL-40). MMP-9 concentrations were higher in the patients with BOS compared with those with non-BOS chronic GVHD (P = .04) or no chronic GVHD (P < .001). MMP-3 concentrations were higher in patients with BOS (P < .001) or non-BOS chronic GVHD (P < .001) compared with those with no chronic GVHD. YKL-40 concentrations did not differ statistically among the 3 groups. MMP-9 concentrations before starting FAM therapy were higher in patients who experienced treatment failure within 6 months compared with those with treatment success (P = .006), whereas MMP-3 or YKL-40 concentrations did not differ statistically between these 2 groups. Patients with an MMP-9 concentration ≥200,000 pg/mL before starting FAM therapy had worse overall survival compared with those with lower MMP-9 concentrations. Our data suggest that plasma MMP-9 concentration could serve as a relevant biomarker at diagnosis of BOS after allogeneic HCT for prognostication of survival and for prediction of treatment response. Further validation is needed to confirm our findings.

Phase II Trial of Costimulation Blockade With Abatacept for Prevention of Acute GVHD.

PURPOSE: Severe (grade 3-4) acute graft-versus-host disease (AGVHD) is a major cause of death after unrelated-donor (URD) hematopoietic cell transplant (HCT), resulting in particularly high mortality after HLA-mismatched transplantation. There are no approved agents for AGVHD prevention, underscoring the critical unmet need for novel therapeutics. ABA2 was a phase II trial to rigorously assess safety, efficacy, and immunologic effects of adding T-cell costimulation blockade with abatacept to calcineurin inhibitor (CNI)/methotrexate (MTX)-based GVHD prophylaxis, to test whether abatacept could decrease AGVHD. METHODS: ABA2 enrolled adults and children with hematologic malignancies under two strata: a randomized, double-blind, placebo-controlled stratum (8/8-HLA-matched URD), comparing CNI/MTX plus abatacept with CNI/MTX plus placebo, and a single-arm stratum (7/8-HLA-mismatched URD) comparing CNI/MTX plus abatacept versus CNI/MTX CIBMTR controls. The primary end point was day +100 grade 3-4 AGVHD, with day +180 severe-AGVHD-free-survival (SGFS) a key secondary end point. Sample sizes were calculated using a higher type-1 error (0.2) as recommended for phase II trials, and were based on predicting that abatacept would reduce grade 3-4 AGVHD from 20% to 10% (8/8s) and 30% to 10% (7/8s). ABA2 enrolled 142 recipients (8/8s, median follow-up = 716 days) and 43 recipients (7/8s, median follow-up = 708 days). RESULTS: In 8/8s, grade 3-4 AGVHD was 6.8% (abatacept) versus 14.8% (placebo) (P = .13, hazard ratio = 0.45). SGFS was 93.2% (CNI/MTX plus abatacept) versus 82% (CNI/MTX plus placebo, P = .05). In the smaller 7/8 cohort, grade 3-4 AGVHD was 2.3% (CNI/MTX plus abatacept, intention-to-treat population), which compared favorably with a nonrandomized matched cohort of CNI/MTX (30.2%, P < .001), and the SGFS was better (97.7% v 58.7%, P < .001). Immunologic analysis revealed control of T-cell activation in abatacept-treated patients. CONCLUSION: Adding abatacept to URD HCT was safe, reduced AGVHD, and improved SGFS. These results suggest that abatacept may substantially improve AGVHD-related transplant outcomes, with a particularly beneficial impact on HLA-mismatched HCT.

HLA-A alleles influencing NK cell function impact AML relapse following allogeneic hematopoietic cell transplantation.

HLA-B allotypes exhibiting the Bw4 epitope trigger variable inhibitory signaling of KIR3DL1 receptor types, where strong inhibitory HLA-B and KIR3DL1 allele combinations are associated with increased risk for relapse of acute myelogenous leukemia (AML) following allogeneic hematopoietic cell transplantation (HCT). Several HLA-A allotypes also exhibit the Bw4 epitope. Studies with natural killer (NK) cell clones have demonstrated NK inhibition via KIR3DL1 by HLA-A Bw4+ allotypes, but did not delineate strengths of inhibition or hierarchies of NK education. Using primary NK cells from healthy donors, we demonstrate that HLA-A*23, HLA-A*24, and HLA-A*32 proteins are expressed at different densities and exhibit different capacities to educate and inhibit KIR3DL1-expressing NK cells in vitro. Among the HLA-A Bw4+ allotypes, HLA-A*24 and HLA-A*32 demonstrate the strongest inhibitory capacity. To determine if HLA-A allotypes with strong inhibitory capacity have similar negative impact in allogeneic HCT as HLA-B Bw4+ allotypes, we performed a retrospective analysis of 1729 patients with AML who received an allogeneic HCT from a 9/10 or 10/10 HLA allele-matched unrelated donor. Examination of the donor-recipient pairs whose Bw4 epitope was exclusively contributed from HLA-A*24 and A*32 allotypes revealed that patients with HLA-A*24 who received an allograft from a KIR3DL1+ donor experienced a higher risk of disease relapse (hazard ratio, 1.65; 95% confidence interval, 1.17-2.32; P = .004) when compared with patients without a Bw4 epitope. These findings indicate that despite weak affinity interactions with KIR3DL1, common HLA-A allotypes with the Bw4 epitope can interact with KIR3DL1+ donor NK cells with clinically meaningful impact and provide additional insight to donor NK alloreactivity in HLA-matched HCT.

Survival, Nonrelapse Mortality, and Relapse-Related Mortality After Allogeneic Hematopoietic Cell Transplantation: Comparing 2003-2007 Versus 2013-2017 Cohorts.

Background: Allogeneic hematopoietic cell transplantation is indicated for refractory hematologic cancer and some nonmalignant disorders. Survival is limited by recurrent cancer and organ toxicity. Objective: To determine whether survival has improved over the past decade and note impediments to better outcomes. Design: The authors compared cohorts that had transplants during 2003 to 2007 versus 2013 to 2017. Survival outcome measures were analyzed, along with transplant-related complications. Setting: A center performing allogeneic transplant procedures. Participants: All recipients of a first allogeneic transplant during 2003 to 2007 and 2013 to 2017. Intervention: Patients received a conditioning regimen, infusion of donor hematopoietic cells, then immunosuppressive drugs and antimicrobial approaches to infection control. Measurements: Day-200 nonrelapse mortality (NRM), recurrence or progression of cancer, relapse-related mortality, and overall mortality, adjusted for comorbidity scores, source of donor cells, donor type, patient age, disease severity, conditioning regimen, patient and donor sex, and cytomegalovirus serostatus. Results: During the 2003-to-2007 and 2013-to-2017 periods, 1148 and 1131 patients, respectively, received their first transplant. Over the decade, decreases were seen in the adjusted hazards of day-200 NRM (hazard ratio [HR], 0.66 [95% CI, 0.48 to 0.89]), relapse of cancer (HR, 0.76 [CI, 0.61 to 0.94]), relapse-related mortality (HR, 0.69 [CI, 0.54 to 0.87]), and overall mortality (HR, 0.66 [CI, 0.56 to 0.78]). The degree of reduction in overall mortality was similar for patients who received myeloablative versus reduced-intensity conditioning, as well as for patients whose allograft came from a matched sibling versus an unrelated donor. Reductions were also seen in the frequency of jaundice, renal insufficiency, mechanical ventilation, high-level cytomegalovirus viremia, gram-negative bacteremia, invasive mold infection, acute and chronic graft-versus-host disease, and prednisone exposure. Limitation: Cohort studies cannot determine causality, and current disease severity criteria were not available for patients in the 2003-to-2007 cohort. Conclusion: Improvement in survival and reduction in complications were substantial after allogeneic transplant. Relapse of cancer remains the largest obstacle to better survival outcomes. Primary Funding Source: National Institutes of Health.

Yttrium-90-labeled anti-CD45 antibody followed by a reduced-intensity hematopoietic cell transplantation for patients with relapsed/refractory leukemia or myelodysplasia.

Outcomes of patients with persistent high-risk leukemia or myelodysplasia prior to allogeneic hematopoietic cell transplantation are dismal. We therefore conducted a phase I trial evaluating the use of CD45-targeted radiotherapy preceding hematopoietic cell transplantation with the goal of improving outcomes for this high-risk scenario. Fifteen patients, median age 62 (range 37-76) years, were treated: ten with advanced acute myeloid leukemia, five with high-risk myelodysplastic syndrome. All patients had evidence of disease prior to treatment including nine with marrow blast counts ranging from 7-84% and six with minimal residual disease. Patients received escalating doses of yttrium-90-labeled anti-CD45 antibody followed by fludarabine and 2 Gy total body irradiation prior to human leukocyte antigen-matched, related or unrelated hematopoietic cell transplantation. Although a maximum dose of 30 Gy was delivered to the liver, no dose-limiting toxicity was observed. Therefore, the maximum-tolerated dose could not be estimated. Treatment led to complete remission in 13 patients (87%). All patients engrafted by day 28. Six patients relapsed, median of 59 (range 6-351) days, after transplantation. The 1-year estimate of relapse was 41%. Eight patients (53%) are surviving with median follow up of 1.8 (range 0.9-5.9) years. Estimated overall survival at one and two years was 66% and 46%, respectively, with progression-free survival estimated to be 46% at each time point. In conclusion, the combination of 90Y-DOTA-BC8 with an allogeneic hematopoietic cell transplantation regimen was feasible and tolerable. This approach appears promising in this high-risk leukemia/myelodysplasia patient population with active disease. (Trial registered at clinicaltrials.gov identifier: NCT01300572).