Disease Status and Interval between Hematopoietic Cell Transplantations Predict Outcome of Pediatric Patients Who Undergo Subsequent Transplantation for Relapsed Hematologic Malignancy

Patients with hematologic malignancies who relapse after allogeneic hematopoietic cell transplantation (HCT) have a poor prognosis. Although proceeding to subsequent HCT can provide potential for long-term survival, there are limited data to guide which patients are most likely to benefit and which HCT strategies are best in this heavily pretreated population. The goals of this study were to describe the clinical outcomes of subsequent HCT in pediatric patients with relapsed hematologic malignancies in a cohort enriched for haploidentical donors, and to evaluate the associations of patient-, disease-, and treatment-related factors with survival. We retrospectively evaluated patients who underwent a subsequent HCT for management of post-HCT relapse at a single institution between 2000 and 2021. Among 106 patients who underwent a second allogeneic HCT, the 1-year event-free survival (EFS) was 34% and 1-year overall survival (OS) was 46%, with a 5-year EFS of 26% and 5-year OS of 31%. Only disease-related factors were associated with outcome after second HCT-specifically, the interval between HCTs and the presence or absence of active disease at the time of HCT. In this cohort, patient- and treatment-related factors were not associated with differences in EFS or OS. Patients undergoing a third or fourth HCT (n = 13) had comparable survival outcomes to those undergoing a second HCT. Our experience highlights that a subsequent HCT has curative potential for a subset of patients who relapse after HCT, including those who undergo a subsequent HCT from a haploidentical donor. Although relapse and treatment-related toxicities remain major challenges, our study indicates that achieving complete remission prior to subsequent HCTs has the potential to further improve outcomes.

Acute kidney injury following treatment with CD19-specific CAR T-cell therapy in children, adolescent, and young adult patients with B-cell acute lymphoblastic leukemia

BACKGROUND

CD19-specific chimeric antigen receptor (CAR) T-cell therapy has shown promising disease responses in patients with high-risk B-cell malignancies. However, its use may be related to complications such as immune-mediated complications, infections, and end-organ dysfunction. The incidence of post-CAR T-cell therapy acute kidney injury (AKI) in the children, adolescent, and young adult (CAYA) patient population is largely unreported.

METHODS

The objectives of this study were to determine the incidence of AKI in CAYA patients with high-risk B-cell malignancies treated with CD19-CAR T-cell therapy, evaluate potential risk factors for developing AKI, and determine patterns of kidney function recovery. We conducted a retrospective analysis of 34 CAYA patients treated with CD19-CAR T-cell at a single institution.

RESULTS

There was a cumulative incidence of any grade AKI by day 30 post-infusion of 20% (n = 7), with four cases being severe AKI (stages 2-3) and one patient requiring kidney replacement therapy. All episodes of AKI developed within the first 14 days after receiving CAR T-cell therapy and 50% of patients with AKI recovered kidney function to baseline within 30 days post-infusion. No evaluated pre-treatment risk factors were associated with the development of subsequent AKI; there was an association between AKI and cytokine release syndrome and neurotoxicity. We conclude that the risk of developing AKI following CD19-CAR T-cell therapy is highest early post-infusion, with most cases of AKI being severe.

CONCLUSIONS

Frequent monitoring to facilitate early recognition and subsequent management of kidney complications after CD19-CAR T-cell therapy may reduce the severity of AKI in the CAYA patient population.

INSPIRED Symposium Part 3: Prevention and Management of Pediatric Chimeric Antigen Receptor T Cell-Associated Emergent Toxicities

Chimeric antigen receptor (CAR) T cell (CAR-T) therapy has emerged as a revolutionary cancer treatment modality, particularly in children and young adults with B cell malignancies. Through clinical trials and real-world experience, much has been learned about the unique toxicity profile of CAR-T therapy. The past decade brought advances in identifying risk factors for severe inflammatory toxicities, investigating preventive measures to mitigate these toxicities, and exploring novel strategies to manage refractory and newly described toxicities, infectious risks, and delayed effects, such as cytopenias. Although much progress has been made, areas needing further improvements remain. Limited guidance exists regarding initial administration of tocilizumab with or without steroids and the management of inflammatory toxicities refractory to these treatments. There has not been widespread adoption of preventive strategies to mitigate inflammation in patients at high risk of severe toxicities, particularly children. Additionally, the majority of research related to CAR-T toxicity prevention and management has focused on adult populations, with only a few pediatric-specific studies published to date. Given that children and young adults undergoing CAR-T therapy represent a unique population with different underlying disease processes, physiology, and tolerance of toxicities than adults, it is important that studies be conducted to evaluate acute, delayed, and long-term toxicities following CAR-T therapy in this younger age group. In this pediatric-focused review, we summarize key findings on CAR-T therapy-related toxicities over the past decade, highlight emergent CAR-T toxicities, and identify areas of greatest need for ongoing research.

Long-term follow-up of CD19-CAR T-cell therapy in children and young adults with B-ALL

The tremendous successes of CD19-directed CAR T cells in children and young adults with B-cell acute lymphoblastic leukemia (B-ALL) has led to the more widespread use of this important treatment modality. With an ability to induce remission and potentially lead to long-term survival in patients with multiply relapsed/chemotherapy refractory disease, more children are now receiving this therapy with the hope of inducing a long-term durable remission (with or without consolidative hematopoietic cell transplantation). While overcoming the acute toxicities was critical to its broad implementation, the emerging utilization requires close evaluation of subacute and delayed toxicities alongside a consideration of late effects and issues related to survivorship following CAR T cells. In this underexplored area of toxicity monitoring, this article reviews the current state of the art in relationship to delayed toxicities while highlighting areas of future research in the study of late effects in children and young adults receiving CAR T cells.

Early and Late Toxicities of Chimeric Antigen Receptor T-Cells

As chimeric antigen receptor (CAR) T-cell therapy is increasingly integrated into clinical practice across a range of malignancies, identifying and treating inflammatory toxicities will be vital to success. Early experiences with CD19-targeted CAR T-cell therapy identified cytokine release syndrome and neurotoxicity as key acute toxicities and led to unified initiatives to mitigate the influence of these complications. In this section, we provide an update on the current state of CAR T-cell-related toxicities, with an emphasis on emerging acute toxicities affecting additional organ systems and considerations for delayed toxicities and late effects.

Acute kidney injury following treatment with CD19-specific CAR T-cell therapy in children, adolescent and young adult patients with B-cell acute lymphoblastic leukemia

CD19-specific chimeric antigen receptor (CAR) T-cell therapy has shown promising disease responses in patients with high-risk B-cell malignancies. Treatment with CD19-CAR T-cell therapy is also associated with the risk of morbidity and mortality, primarily related to immune-mediated complications (cytokine release syndrome [CRS] and neurotoxicity [NTX]), infections, and end-organ dysfunction. Despite these well-described systemic toxicities, the incidence of post-CAR T-cell therapy acute kidney injury (AKI) in the children, adolescent and young adult (CAYA) patient population is largely unreported. The objectives of this study were to determine the incidence of AKI in CAYA patients with high-risk B-cell malignancies treated with CD19-CAR T-cell therapy, evaluate potential risk factors for developing AKI, and determine patterns of kidney function recovery. In this retrospective analysis of 34 CAYA patients treated with CD19-CAR T-cell at a single institution, we found a cumulative incidence of any grade AKI by day 30 post-infusion of 20% (n=7), with 4 cases being severe AKI (Stage 2-3) and one patient requiring kidney replacement therapy. All episodes of AKI developed within the first 14 days after receiving CAR T-cell therapy and 50% of patients with AKI recovered kidney function to baseline within 30 days post-infusion. No evaluated pre-treatment risk factors were associated with the development of subsequent AKI; there was an association between AKI and CRS and NTX. We conclude that the risk of developing AKI following CD19-CAR T-cell therapy is highest early post-infusion, with most cases of AKI being severe. Although most patients with AKI in our cohort had recovery of kidney function, frequent monitoring to facilitate early recognition and subsequent management of kidney complications after CD19-CAR T-cell therapy may reduce the severity of AKI in the CAYA patient population.

Integration of Palliative Care in Hematopoietic Cell Transplant: Pediatric Patient and Parent Needs and Attitudes

CONTEXT

Early integration of palliative care (PC) in hematopoietic cell transplantation (HCT) has demonstrated benefits, yet barriers remain, including perceived lack of patient/caregiver receptivity despite no data on attitudes toward PC and limited patient/caregiver reported outcomes in pediatric HCT.

OBJECTIVES

This study aimed to evaluate perceived symptom burden and patient/parent attitudes toward early PC integration in pediatric HCT.

METHODS

Following IRB approval, consent/assent, eligible participants were surveyed at St. Jude Children's Research Hospital including English-speaking patients aged 10-17, 1-month to 1-year from HCT, and their parents/primary-caregivers, as well as parent/primary-caregivers of living HCT recipients

RESULTS

Eighty one participants, within one year of HCT, at St. Jude Children's Research Hospital were enrolled including: 36 parents of patients

CONCLUSION

Our findings suggest that patient/family receptivity should not be a barrier to early PC in pediatric HCT; obtaining patient reported outcomes is a priority in the setting of high symptom burden; and robust quality-of-life directed care with early PC integration is both indicated and acceptable to patients/caregivers.

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Key Words

• Palliative care
• caregivers
• hematopoietic cell transplantation
• patients
• pediatrics
• quality of life

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MESH Headings

• Humans
• Child
• Palliative Care
• Hematopoietic Stem Cell Transplantation
• Patients
• Parents
• Quality of Life
• Attitude
• Caregivers

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Affiliation(s)

Deena R Levine Division of Quality-of-life and Palliative Care, Department of Oncology (D.R.L., G.C., J.N.B.), St. Jude Children's Research Hospital, Memphis, TN, USA.
Rebecca Epperly Department of Bone Marrow Transplantation and Cellular Therapy (R.E., A.C.T.), St. Jude Children's Research Hospital, Memphis, TN, USA
Griffin Collins Division of Quality-of-life and Palliative Care, Department of Oncology (D.R.L., G.C., J.N.B.), St. Jude Children's Research Hospital, Memphis, TN, USA
Aimee C Talleur Department of Bone Marrow Transplantation and Cellular Therapy (R.E., A.C.T.), St. Jude Children's Research Hospital, Memphis, TN, USA
Belinda Mandrell Division of Nursing Research, Department of Pediatric Medicine (B.M., M.P.), St. Jude Children's Research Hospital, Memphis, TN, USA
Michele Pritchard Division of Nursing Research, Department of Pediatric Medicine (B.M., M.P.), St. Jude Children's Research Hospital, Memphis, TN, USA
Suraj Sarvode Mothi Department of Biostatistics (S.S.M., C.L., Z.L.), St. Jude Children's Research Hospital, Memphis, TN
Chen Li Department of Biostatistics (S.S.M., C.L., Z.L.), St. Jude Children's Research Hospital, Memphis, TN
Zhaohua Lu Department of Biostatistics (S.S.M., C.L., Z.L.), St. Jude Children's Research Hospital, Memphis, TN
Justin N Baker Division of Quality-of-life and Palliative Care, Department of Oncology (D.R.L., G.C., J.N.B.), St. Jude Children's Research Hospital, Memphis, TN, USA

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Outcomes following intolerance to calcineurin inhibitor-based graft-versus-host disease prophylaxis in children after allogeneic hematopoietic cell transplantation

Calcineurin inhibitors (CNI), cyclosporine and tacrolimus, are commonly used for pharmacologic prophylaxis of graft-versus-host disease after allogeneic hematopoietic cell transplantation (HCT). Unfortunately, their use is associated with significant toxicities. While intolerance to CNI is well defined, there is very little information on how they impact outcomes after HCT in children. Our retrospective study in a cohort of 82 children shows a high intolerance rate of 39% in this population associated with lower event-free survival and a higher transplant-related mortality.

Nutrition management of pediatric patients undergoing hematopoietic stem cell transplantation: Guidelines, gaps, and research

Medical nutrition therapy (MNT) is a key component of supportive care for children undergoing hematopoietic stem cell transplantation. During the transplant process, several complications and side effects may be encountered that require alteration of the nutrition support, interventions, and monitoring provided. The focus of this review is to discuss current guidelines and research for the provision of MNT to these patients, along with recommendations on how to bridge the gap in MNT knowledge.

Abstract 1197: B7-H3-CAR T cells for the treatment of pediatric adrenocortical carcinoma

Outcomes for pediatric patients with unresectable, metastatic, or relapsed adrenocortical carcinoma (ACC) are dismal despite aggressive management with multimodality therapies. CAR T cell therapy (CAR T) is a promising approach to improve outcomes for patients with this disease. However, progress is hindered by a lack of targetable surface antigens and limited availability of relevant preclinical models. B7-H3 is a promising immunotherapeutic target but little is known about its expression in pediatric ACC. Thus, we sought to i) evaluate B7-H3 expression in primary pediatric ACC samples and ii) assess B7-H3-CAR T activity in two novel pediatric patient-derived xenograft (PDX) models. First, we assessed B7-H3 expression in 44 pediatric adrenocortical tumors (ACTs) using a CLIA-approved immunohistochemistry (IHC) assay. ACTs had a range of B7-H3 positivity, including 24 (55%) with expression above the threshold for eligibility on our active B7-H3-CAR T clinical trial (H-score ≥ 100; NCT04897321). Univariate analyses demonstrated B7-H3 expression was correlated with the presence of germline TP53 mutations and poor prognostic factors including the inability to achieve complete resection, Cushing phenotype, and the absence of TP53 by IHC. Given a dearth of in vivo models, we next established two clinically relevant pediatric ACC PDX models. SJ-ACC4 was derived from a metastatic tumor and had somatic mutations in TP53 (p.C135Lfs*14) and CTNNB1 (p.S45F). SJACT030812_X1 (www.stjude.org/cstn) was derived from a primary tumor and had a germline TP53 mutation (p.R110Pfs*39). Both had partial ATRX deletions (exons 11-30; 3-28), uniparental disomy at chromosome 11p15, and were B7-H3-positive. Notably, SJ-ACC4 was resistant to a battery of chemotherapeutic agents. To evaluate B7-H3-CAR T anti-ACC activity in vivo, SJ-ACC4 tumor fragments were implanted subcutaneously in NOD SCID gamma (NSG) mice and treated with B7-H3-CAR or control T cells. Strikingly, B7-H3-CAR T eradicated 100% of SJ-ACC4 tumors and mice survived long term compared to controls that met endpoints within 35 days (n=8 per group, p< 0.0001). Finally, we asked if B7-H3-CAR T had antitumor activity in an orthotopic pediatric ACC PDX model. SJACT030812_X1 cells were injected into the para-adrenal region of NSG mice under ultrasound guidance and monitored by serial volumetric ultrasonography. B7-H3-CAR T again had significant antitumor activity, and mice survived long-term compared to controls that met endpoints within 42 days (n=5 per group, p< 0.01). In conclusion, B7-H3 is expressed in a majority of pediatric ACTs and B7-H3-CAR T have potent anti-ACC activity. These findings provide a strong rationale for clinically evaluating B7-H3-CAR T for pediatric patients with chemotherapy-resistant ACC. Additionally, the newly established pediatric ACC PDX models provide a valuable resource for investigating different aspects of this rare and aggressive disease.

Citation Format: Rebecca Epperly, Emilia M. Pinto, Teresa Santiago, Heather Sheppard, Michael R. Clay, Christopher Morton, Phuong Nguyen, Yinmei Zhou, Mary Woolard, Carla O'Reilly, Julie Justice, Walter Akers, Melissa Johnson, Asa Karlstrom, Cheng Cheng, Gerard Zambetti, Andrew Davidoff, Raul Ribeiro, Christopher DeRenzo. B7-H3-CAR T cells for the treatment of pediatric adrenocortical carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1197.

Sub-myeloablative Second Transplantations with Haploidentical Donors and Post-Transplant Cyclophosphamide have limited Anti-Leukemic Effects in Pediatric Patients

Pediatric patients with high-risk hematologic malignancies who experience relapse after a prior allogeneic hematopoietic cell transplant (HCT) have an exceedingly poor prognosis. A second allogeneic HCT offers the potential for long-term cure but carries high risks of both subsequent relapse and HCT-related morbidity and mortality. Using haploidentical donors for HCT (haploHCT) can expand the donor pool and potentially enhance the graft-versus-leukemia effect but is accompanied by a risk of graft-versus-host disease (GVHD). The goal of this protocol was to intensify the antileukemia effect of haploHCT for pediatric patients with hematologic malignancies that relapsed after prior allogeneic HCT, while limiting regimen-associated toxicities. This phase II clinical trial evaluated a sub-myeloablative preparative regimen consisting of anti-thymocyte globulin, clofarabine, cytarabine, busulfan, and cyclophosphamide, in combination with plerixafor to sensitize leukemic blasts. Participants received a mobilized peripheral blood unmanipulated haploidentical donor graft with one dose of post-transplant cyclophosphamide as GVHD prophylaxis, followed by natural killer (NK) cell addback. Here we report the clinical outcomes and immune reconstitution of 17 participants treated on the study and 5 additional patients treated on similar single-patient treatment plans. Of the 22 participants analyzed, 12 (55%) had active disease at the time of HCT. The regimen provided robust immune reconstitution, with 21 participants (95%) experiencing neutrophil engraftment at a median of 14 days after HCT. In this high-risk population, the overall survival was 45% (95% confidence interval [CI], 24%-64%), with a 12-month event-free survival of 31% (95% CI, 14%-51%) and cumulative incidence of relapse at 12 months of 50% (95% CI, 27%-69%). Four participants (18%) remain in remission at >5 years follow-up. Expected HCT-related organ-specific toxicities were observed, and 13 participants (59%) experienced acute or chronic GVHD. This intensified but sub-myeloablative regimen, followed by a high-dose unmanipulated haploidentical graft, post-transplantation cyclophosphamide, and NK cell infusion, resulted in adequate immune reconstitution but failed to overcome the elevated risks of relapse and treatment-related morbidity in this high-risk population.

Infectious Complications in Pediatric, Adolescent and Young Adult Patients Undergoing CD19-CAR T Cell Therapy

CD19-specific chimeric antigen receptor (CAR) T cell therapy has changed the treatment paradigm for pediatric, adolescent and young adult (AYA) patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, data on the associated infectious disease challenges in this patient population are scarce. Knowledge of infections presenting during treatment, and associated risk factors, is critical for pediatric cellular therapy and infectious disease specialists as we seek to formulate effective anti-infective prophylaxis, infection monitoring schemas, and empiric therapy regimens. In this work we describe our institutional experience in a cohort of 38 pediatric and AYA patients with CD19-positive malignancy treated with lymphodepleting chemotherapy (fludarabine/cyclophosphamide) followed by a single infusion of CD19-CAR T cells (total infusions, n=39), including tisagenlecleucel (n=19; CD19/4-1BB) or on an institutional clinical trial (n=20; CD19/4-1BB; NCT03573700). We demonstrate that infections were common in the 90 days post CAR T cells, with 19 (50%) patients experiencing a total of 35 infections. Most of these (73.7%) occurred early post infusion (day 0 to 28; infection density of 2.36 per 100 patient days-at-risk) compared to late post infusion (day 29 to 90; infection density 0.98 per 100 patient days-at-risk), respectively. Bacterial infections were more frequent early after CAR T cell therapy, with a predominance of bacterial blood stream infections. Viral infections occurred throughout the post infusion period and included primarily systemic reactivations and gastrointestinal pathogens. Fungal infections were rare. Pre-infusion disease burden, intensity of bridging chemotherapy, lymphopenia post lymphodepleting chemotherapy/CAR T cell infusion and development of CAR-associated hemophagocytic lymphohistiocytosis (carHLH) were all significantly associated with either infection density or time to first infection post CAR T cell infusion. A subset of patients (n=6) had subsequent CAR T cell reinfusion and did not appear to have increased risk of infectious complications. Our experience highlights the risk of infections after CD19-CAR T cell therapy, and the need for continued investigation of infectious outcomes as we seek to improve surveillance, prophylaxis and treatment algorithms.

CAR T cells redirected to cell surface GRP78 display robust anti-acute myeloid leukemia activity and do not target hematopoietic progenitor cells

Developing CAR T cells for acute myeloid leukemia (AML) has been hampered by a paucity of targets that are expressed on AML blasts and not on hematopoietic progenitor cells (HPCs). Here we demonstrate that GRP78 is expressed on the cell surface of primary AML blasts but not HPCs. To target GRP78, we generate T cell expressing a GRP78-specific peptide-based CAR, which show evidence of minimal fratricide post activation/transduction and antigen-dependent T cell differentiation. GRP78-CAR T cells recognize and kill GRP78-positive AML cells without toxicity to HPCs. In vivo, GRP78-CAR T cells have significant anti-AML activity. To prevent antigen-dependent T cell differentiation, we block CAR signaling and GRP78 cell surface expression post activation by using dasatinib during GRP78-CAR T cell manufacturing. This significantly improves their effector function in vitro and in vivo. Thus, targeting cell surface GRP78-positive AML with CAR T cells is feasible, and warrants further active exploration.

Targeting plasma cells with daratumumab aids in the treatment of post-transplant autoimmune-like hepatitis

Antibody-mediated autoimmune-like hepatitis is a rare and challenging occurrence after hematopoietic cell transplant (HCT). We present the case of a 16-year-old male patient with Ph+ ALL who underwent matched sibling donor HCT and developed autoimmune-like hepatitis after receiving ponatinib for post-HCT maintenance, evidenced by marked plasma cell infiltrate on liver biopsy. He was successfully treated with steroids and daratumumab, an anti-CD38-monoclonal antibody. The dramatic response in this patient warrants expanded investigation of daratumumab for plasma cell-mediated disorders post-HCT. It further highlights that identifying mechanisms of immune-mediated injury can allow for directed therapy and limit exposure to broad immune suppression.

A Bump in the Road: How the Hostile AML Microenvironment Affects CAR T Cell Therapy

Chimeric antigen receptor (CAR) T cells targeting CD19 have been successful treating patients with relapsed/refractory B cell acute lymphoblastic leukemia (ALL) and B cell lymphomas. However, relapse after CAR T cell therapy is still a challenge. In addition, preclinical and early clinical studies targeting acute myeloid leukemia (AML) have not been as successful. This can be attributed in part to the presence of an AML microenvironment that has a dampening effect on the antitumor activity of CAR T cells. The AML microenvironment includes cellular interactions, soluble environmental factors, and structural components. Suppressive immune cells including myeloid derived suppressor cells and regulatory T cells are known to inhibit T cell function. Environmental factors contributing to T cell exhaustion, including immune checkpoints, anti-inflammatory cytokines, chemokines, and metabolic alterations, impact T cell activity, persistence, and localization. Lastly, structural factors of the bone marrow niche, secondary lymphoid organs, and extramedullary sites provide opportunities for CAR T cell evasion by AML blasts, contributing to treatment resistance and relapse. In this review we discuss the effect of the AML microenvironment on CAR T cell function. We highlight opportunities to enhance CAR T cell efficacy for AML through manipulating, targeting, and evading the anti-inflammatory leukemic microenvironment.

Harnessing T Cells to Target Pediatric Acute Myeloid Leukemia: CARs, BiTEs, and Beyond

Outcomes for pediatric patients with acute myeloid leukemia (AML) remain poor, highlighting the need for improved targeted therapies. Building on the success of CD19-directed immune therapy for acute lymphocytic leukemia (ALL), efforts are ongoing to develop similar strategies for AML. Identifying target antigens for AML is challenging because of the high expression overlap in hematopoietic cells and normal tissues. Despite this, CD123 and CD33 antigen targeted therapies, among others, have emerged as promising candidates. In this review we focus on AML-specific T cell engaging bispecific antibodies and chimeric antigen receptor (CAR) T cells. We review antigens being explored for T cell-based immunotherapy in AML, describe the landscape of clinical trials upcoming for bispecific antibodies and CAR T cells, and highlight strategies to overcome additional challenges facing translation of T cell-based immunotherapy for AML.

Secondary hemophagocytic syndrome after autologous hematopoietic cell transplant and immune therapy for neuroblastoma

Secondary hemophagocytic syndrome (HPS) has been described after autologous hematopoietic cell transplant (AutoHCT). We report two cases of secondary HPS after novel consolidation therapy for high-risk neuroblastoma as part of an institutional phase 2 trial incorporating immunotherapy into a "standard" AutoHCT regimen. Both patients developed liver dysfunction beyond expected course of hepatic veno-occlusive disease, coagulopathy, hyperferritinemia, and when evaluated, elevated soluble interleukin-2 receptor and hemophagocytosis. These cases highlight the need for clinicians to have a high index of suspicion for immune-related complications in patients receiving immune therapies.

Treatment of pediatric plasma cell myeloma type post-transplant lymphoproliferative disorder with modern risk-directed therapy

Post-transplant lymphoproliferative disorder (PTLD) related plasma cell neoplasms are rare in pediatric patients. We report a pediatric liver transplant recipient with plasma cell myeloma type PTLD. Cytogenetics included 1q duplication, associated with poor prognosis in adult multiple myeloma, and t(8;14). High-risk cytogenetics has not been reported in pediatric plasma cell myeloma type PTLD. The patient was treated with bortezomib, dexamethasone, and lenalidomide with subsequent autologous stem cell transplant. He achieved a 6-year remission, demonstrating tolerance to and efficacy of this modern myeloma regimen in a pediatric patient. Unfortunately, he subsequently died from complications of repeat liver transplant.