Toxicity and response after CD19-specific CAR T-cell therapy in pediatric/young adult relapsed/refractory B-ALL.

Chimeric antigen receptor (CAR) T cells have demonstrated clinical benefit in patients with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). We undertook a multicenter clinical trial to determine toxicity, feasibility, and response for this therapy. A total of 25 pediatric/young adult patients (age, 1-22.5 years) with R/R B-ALL were treated with 19-28z CAR T cells. Conditioning chemotherapy included high-dose (3 g/m2) cyclophosphamide (HD-Cy) for 17 patients and low-dose (≤1.5 g/m2) cyclophosphamide (LD-Cy) for 8 patients. Fifteen patients had pretreatment minimal residual disease (MRD; <5% blasts in bone marrow), and 10 patients had pretreatment morphologic evidence of disease (≥5% blasts in bone marrow). All toxicities were reversible, including severe cytokine release syndrome in 16% (4 of 25) and severe neurotoxicity in 28% (7 of 25) of patients. Treated patients were assessed for response, and, among the evaluable patients (n = 24), response and peak CAR T-cell expansion were superior in the HD-Cy/MRD cohorts, as compared with the LD-Cy/morphologic cohorts without an increase in toxicity. Our data support the safety of CD19-specific CAR T-cell therapy for R/R B-ALL. Our data also suggest that dose intensity of conditioning chemotherapy and minimal pretreatment disease burden have a positive impact on response without a negative effect on toxicity. This trial was registered at www.clinicaltrials.gov as #NCT01860937.

11p15.5 epimutations in children with Wilms tumor and hepatoblastoma detected in peripheral blood.

BACKGROUND: Constitutional or somatic mosaic epimutations are increasingly recognized as a mechanism of gene dysregulation resulting in cancer susceptibility. Beckwith-Wiedemann syndrome is the cancer predisposition syndrome most commonly associated with epimutation and is extremely variable in its phenotypic presentation, which can include isolated tumors. Because to the authors' knowledge large-scale germline DNA sequencing studies have not included methylation analysis, the percentage of pediatric cancer predisposition that is due to epimutations is unknown. METHODS: Germline methylation testing at the 11p15.5 locus was performed in blood for 24 consecutive patients presenting with hepatoblastoma (3 patients) or Wilms tumor (21 patients). RESULTS: Six individuals with Wilms tumor and 1 patient with hepatoblastoma were found to have low-level gain of methylation at imprinting control 1, and a child with hepatoblastoma was found to have loss of methylation at imprinting control 2. The loss of methylation at imprinting control 2 was found to be maternally inherited, despite not being associated with any detectable genomic alteration. CONCLUSIONS: Overall, 33% of patients (8 of 24 patients) with Wilms tumor or hepatoblastoma were found to have an epigenetic susceptibility that was detectable in the blood. It is interesting to note that low-level gain of methylation at imprinting control 1 predominantly was detected in females with bilateral Wilms tumors. Further studies in larger cohorts are needed to determine the efficacy of testing all patients with Wilms tumor or hepatoblastoma for 11p15.5 epimutations in the blood as part of DNA analysis because this hallmark of predisposition will not be detected by sequencing-based approaches and detecting a cancer predisposition may modify treatment.

Maintenance chemotherapy to reduce the risk of a metachronous Wilms tumor in children with bilateral nephroblastomatosis.

From 2009 to 2018, 10 consecutive patients with Wilms tumors and bilateral nephroblastomatosis, who had completed standard therapy, were provided a maintenance chemotherapy regimen consisting of vincristine and dactinomycin every 3 months for 12 months in order to prevent an early metachronous Wilms tumor. One patient (10%) with Beckwith-Wiedemann syndrome developed a new tumor, without anaplasia. There were no significant toxicities reported during maintenance. All patients are currently alive with no evidence of disease. Further investigations are recommended to determine the utility of this approach.

Germline ETV6 Mutations Confer Susceptibility to Acute Lymphoblastic Leukemia and Thrombocytopenia.

Somatic mutations affecting ETV6 often occur in acute lymphoblastic leukemia (ALL), the most common childhood malignancy. The genetic factors that predispose to ALL remain poorly understood. Here we identify a novel germline ETV6 p. L349P mutation in a kindred affected by thrombocytopenia and ALL. A second ETV6 p. N385fs mutation was identified in an unrelated kindred characterized by thrombocytopenia, ALL and secondary myelodysplasia/acute myeloid leukemia. Leukemic cells from the proband in the second kindred showed deletion of wild type ETV6 with retention of the ETV6 p. N385fs. Enforced expression of the ETV6 mutants revealed normal transcript and protein levels, but impaired nuclear localization. Accordingly, these mutants exhibited significantly reduced ability to regulate the transcription of ETV6 target genes. Our findings highlight a novel role for ETV6 in leukemia predisposition.

Allogeneic Hematopoietic Stem Cell Transplantation with Myeloablative Conditioning Is Associated with Favorable Outcomes in Mixed Phenotype Acute Leukemia.

Mixed phenotype acute leukemia (MPAL) represents a poorly characterized group of acute leukemias that lack an accepted therapeutic approach and are typically associated with poor outcomes. We present our experience of genomic profiling, pretransplantation therapy, and transplantation outcomes for 36 well-characterized pediatric and adult patients with MPAL, defined according to the 2016 World Health Organization leukemia update. A predominance of acute lymphoid leukemia (ALL)-associated mutations and cytogenetic abnormalities was noted. Remission rates after induction appeared comparable among adults (20 of 23) and children (11 of 13) and among those who received ALL (10 of 11) or acute myeloid leukemia-type (21 of 25) induction. Adults underwent transplantation in first remission while children underwent transplantation in the setting of relapse or MLL rearrangement. The median follow-up among the 25 patients who underwent transplantation was 39.6 months and median overall survival was not reached. Relapse after transplantation was associated with MLL rearrangement (P = .022), reduced-intensity conditioning (P < .001), and higher WBC at diagnosis (P = .034). These data highlight differing therapeutic approaches between adult and pediatric MPAL and demonstrate favorable survival of adult MPAL patients consolidated with allogeneic hematopoietic cell transplantation.

PET-adapted sequential salvage therapy with brentuximab vedotin followed by augmented ifosamide, carboplatin, and etoposide for patients with relapsed and refractory Hodgkin's lymphoma: a non-randomised, open-label, single-centre, phase 2 study.

BACKGROUND: Pre-transplantation (18)F-fluorodeoxyglucose (FDG) PET-negativity is one of the strongest predictors of outcome after high-dose therapy and autologous stem-cell transplant (HDT/ASCT) for patients with relapsed or refractory Hodgkin's lymphoma. In this study, we assessed the feasibility and activity of PET-adapted salvage therapy with brentuximab vedotin, followed by augmented ifosfamide, carboplatin, and etoposide (ICE). METHODS: In this non-randomised, open-label, single-centre, phase 2 trial, we enrolled patients with relapsed or refractory Hodgkin's lymphoma who had failed one previous doxorubicin-containing chemotherapy regimen. All patients received weekly infusions of 1·2 mg/kg brentuximab vedotin on days 1, 8, and 15 for two 28 day cycles. After completion of brentuximab vedotin treatment, patients received a PET scan. Patients who achieved PET-negative status (a Deauville score of 1 or 2) proceeded directly to HDT/ASCT; those with persistent abnormalities on PET received two cycles of augmented ICE (augICE; two doses of ifosfamide 5000 mg/m(2) in combination with mesna 5000 mg/m(2) continuous infusion over 24 h, days 1 and 2; one dose of carboplatin AUC 5, day 3; three doses of etoposide 200 mg/m(2) every 12 h, day 1) before consideration for HDT/ASCT. Only patients with persistent abnormalities on PET after brentuximab vedotin received augICE; however, all patients in the intention-to-treat population were assessed for the primary outcome, which was the proportion of patients who were PET-negative after brentuximab vedotin alone or brentuximab vedotin followed by augICE. This study is registered with ClinicalTrials.gov, number NCT01508312, and is no longer accruing patients. FINDINGS: Between Jan 5, 2012, and Oct 4, 2013, we enrolled 46 patients. One patient was deemed ineligible, and not evaluable, before treatment initiation owing to having nodular, lymphocyte-predominant Hodgkin's lymphoma and thus 45 patients received treatment. After brentuximab vedotin, 12 patients (27%, 95% CI 13-40) were PET-negative and proceeded to HDT/ASCT. 33 (73%, 95% CI 60-86) patients were PET-positive after brentuximab vedotin; one PET-positive patient withdrew consent, therefore 32 PET-positive patients received augICE, 22 (69%, 95% CI 53-85) of whom were PET-negative. Overall, 34 patients (76%, 95% CI 62-89) achieved PET-negativity. All 44 patients who completed treatment as per protocol proceeded to receive HDT/ASCT. Brentuximab vedotin was well tolerated and associated with few grade 3-4 adverse events including hyperglycaemia (two [4%] patients, grade 3), nausea (one [2%], grade 3), hypoglycaemia (one [2%], grade 3 and one [2%], grade 4), and hypocalcaemia (one [2%], grade 3 and one [2%], grade 4). INTERPRETATION: PET-adapted sequential salvage therapy with brentuximab vedotin followed by augICE resulted in a high proportion of patients with relapsed or refractory Hodgkin's lymphoma achieving PET-negativity, and therefore could optimise the chance of cure after HDT/ASCT. FUNDING: Seattle Genetics.

ALK-positive (2p23 rearranged) anaplastic large cell lymphoma with localization to the skin in a pediatric patient.

Anaplastic large cell lymphoma (ALCL) either as primary cutaneous or nodal disease is rare in children and difficult to distinguish, which is important both prognostically and for treatment purposes. We present a case of anaplastic lymphoma kinase (ALK)+ skin-limited ALCL that highlights this challenge and draws attention to pitfalls in assessing ALK status. The patient was an 11-year old girl with a twice recurrent nodule on her right shoulder. Each biopsy revealed a deep infiltrate of atypical lymphocytes that expressed CD3, CD4, CD43, CD45RO and CD30. The initial biopsy was epithelial membrane antigen (EMA)+ with vague cytoplasmic ALK-1 positivity by immunohistochemistry, while the second biopsy was EMA+ and nuclear ALK-1+. Fluorescence in situ hybridization analysis for an ALK (2p23) rearrangement of the first specimen was negative, while an ALK gene rearrangement was present in the second specimen. Therefore, this case was treated as nodal ALCL, despite negative bone marrow and radiographic imaging studies. The patient was treated with combination chemotherapy and remains disease-free. Demonstration of nuclear ALK-positivity, ALK (2p23) gene rearrangement is suggestive of systemic ALCL. Without evidence of systemic disease, this case highlights challenges of skin-limited ALCL, whose clinical behavior as either cutaneous ALCL systemic ALCL may not be immediately apparent.

Phase II trial of clofarabine with topotecan, vinorelbine, and thiotepa in pediatric patients with relapsed or refractory acute leukemia.

BACKGROUND: Outcomes for children with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) are dismal. In an effort to improve outcomes, we performed a phase I/II study of a novel clofarabine based combination regimen called TVTC. Herein, we report the response rates of patients in the phase II portion of the study. PROCEDURE: Seventeen patients with R/R ALL, AML, or biphenotypic leukemia were enrolled. Sixteen patients were evaluable for response. Patients were treated at the maximum tolerated dose (MTD) from the phase I portion of the study (clofarabine 40 mg/m(2) /day IV × 5 days, topotecan 1 mg/m(2) /day IV continuous infusion × 5 days, vinorelbine 20 mg/m(2) /week IV × 3 weeks, thiotepa 15 mg/m(2)/day IV × 1 day). The primary endpoint was overall response rate (ORR), defined as CR or CR without platelet recovery (CRp). RESULTS: The ORR was 69% (10 CR, 1 CRp). Among the 11 responders, 9 (82%) proceeded to hematopoietic stem cell transplantation. The most common grade 3+ non-hematologic toxicities were febrile neutropenia (82%) and transient transaminase elevation (47%). CONCLUSIONS: TVTC demonstrates significant activity in patients with R/R acute leukemia. The activity in R/R AML patients was very encouraging, with 8 of 12 (67%) patients achieving a CR/CRp. Patients with high risk de novo AML may benefit from incorporation of TVTC therapy into frontline treatment regimens. This regimen warrants further exploration in a larger cohort of patients with R/R leukemia.

High-dose cyclophosphamide for the treatment of refractory T-cell acute lymphoblastic leukemia in children.

Despite an almost 80% overall survival rate in pediatric T-cell acute lymphoblastic leukemia (T-ALL), there is a subset of patients who are refractory to standard chemotherapy regimens and could benefit from novel treatment approaches. Over a 2-year period, we treated 5 pediatric patients with refractory T-ALL, aged 3 to 15 years, with high-dose cyclophosphamide (CY) at a dose of 2100 mg/m for 2 consecutive days either alone (n=1) or in combination with other chemotherapy agents (n=4). Four of these 5 patients had a 1.5 log decrease in disease burden. Three of the 5 patients had no evidence of minimal residual disease (MRD) after high-dose CY. One patient developed transient grade 4 transaminitis and 1 patient developed grade 3 typhlitis. All 5 patients ultimately proceeded to hematopoietic stem cell transplant when MRD levels were <0.01%. Pediatric T-ALL patients with persistent MRD after treatment with conventional chemotherapy may respond to CY at escalated dosing.

Phase 2 trial of clofarabine in combination with etoposide and cyclophosphamide in pediatric patients with refractory or relapsed acute lymphoblastic leukemia.

The outcomes in children with refractory/relapsed (R/R) acute lymphoblastic leukemia (ALL) are dismal. The efficacy and safety of intravenous clofarabine 40 mg/m(2) per day, cyclophosphamide 440 mg/m(2) per day, and etoposide 100 mg/m(2) per day for 5 consecutive days in pediatric patients with R/R ALL was evaluated in this phase 2 study. The primary endpoint was overall response rate (complete remission [CR] plus CR without platelet recovery [CRp]). Among the 25 patients (median age, 14 years; pre-B cell ALL, 84%; ≥ 2 prior regimens: 84%; refractory to previous regimen: 60%), the overall response rate was 44% (7 CR, 4 CRp) with a 67.3-week median duration or remission censored at last follow-up. Most patients proceeded to alternative therapy, and 10 patients (40%) received hematopoietic stem cell transplantation. Six patients (24%) died because of treatment-related adverse events associated with infection, hepatotoxicity, and/or multiorgan failure. The study protocol was amended to exclude patients with prior hematopoietic stem cell transplantation after 4 of the first 8 patients developed severe hepatotoxicity suggestive of veno-occlusive disease. No additional cases of veno-occlusive disease occurred. The regimen offered encouraging response rates and sustained remission in R/R patients. Future investigation should include exploration of patient selection, dosing, and supportive care. This trial was registered at www.clinicaltrials.gov as #NCT00315705.

Ten-year follow-up of pediatric patients with non-Hodgkin lymphoma treated with allogeneic or autologous stem cell transplantation.

BACKGROUND: Autologous or allogeneic hematopoietic stem cell transplant (SCT) is often considered in patients with relapsed or refractory non-Hodgkin lymphoma (NHL) but there are limited data on the use of SCT for the treatment of NHL in the pediatric setting. PROCEDURE: To evaluate the role of SCT for children with NHL, we reviewed 36 consecutive pediatric patients with NHL who underwent an allogeneic (n = 21) or autologous (n = 15) SCT at our institution between 1982 and 2004. Pathologic classification included: lymphoblastic lymphoma (n = 12), Burkitt lymphoma (BL) (n = 5), diffuse large B-cell lymphoma (n = 4), anaplastic large cell lymphoma (ALCL) (n = 13), peripheral T cell lymphoma (n = 1), and undifferentiated NHL (n = 1). Donor source for allogeneic-SCT recipients was an HLA-matched related donor (n = 15), a matched unrelated donor (n = 4), or a mismatched donor (related n = 1; unrelated n = 1). Twenty-eight patients (78%) had chemotherapy responsive disease at the time of transplant (either CR or PR). RESULTS: Overall survival (OS) and disease-free survival (DFS) were 55% and 53% with a median follow-up of 9.75 years. Outcomes were similar in patients receiving autologous and allogeneic-SCT (DFS 53% in both groups). Patients with ALCL had a DFS of 76.9%. In contrast, of five patients transplanted for BL, none survived. DFS among patients with chemotherapy sensitive disease was 61%, compared with 25% among patients with relapsed/refractory disease (P = 0.019). CONCLUSIONS: Allogeneic and autologous SCT offer the prospect of durable, disease-free survival for a significant proportion of pediatric patients with relapsed or refractory NHL. Survival is superior among patients with chemotherapy sensitive disease.

Effect of alternate-week versus continuous dexamethasone scheduling on the risk of osteonecrosis in paediatric patients with acute lymphoblastic leukaemia: results from the CCG-1961 randomised cohort trial.

BACKGROUND: Acute lymphoblastic leukaemia (ALL) is curable in more than 80% of children and adolescents who exhibit high-risk features. However, treatments are associated with symptomatic osteonecrosis that disproportionately affects adolescents. Based on the findings from the CCG-1882 trial, the CCG-1961 trial was designed to assess whether dexamethasone dose modification would reduce the risk of osteonecrosis. We therefore compared use of continuous versus alternate-week dexamethasone within standard and intensified post-induction treatments. METHODS: In the CCG-1961 trial, a multicohort cooperative group trial, 2056 patients (aged 1-21 years) with newly diagnosed high-risk ALL (age ≥10 years, white blood cell count ≥50×10(9) per L, or both) were recruited. To address osteonecrosis, a novel alternate-week schedule of dexamethasone (10 mg/m(2) per day on days 0-6 and 14-20) was compared with standard continuous dexamethasone (10 mg/m(2) per day on days 0-20) in computer-generated randomised regimens with permuted blocks within double or single delayed intensification phases, respectively. Masking was not possible because of the differences in the treatments. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00002812. FINDINGS: Symptomatic osteonecrosis was diagnosed in 143 patients at 377 confirmed skeletal sites, resulting in 139 surgeries. In patients aged 1-21 years, the overall cumulative incidence of osteonecrosis at 5 years was 7·7% (SE 0·9), correlating with age at ALL diagnosis (1-9 years, 1·0% [0·5]; 10-15 years, 9·9% [1·5], hazard ratio 10·4 [4·8-22·5]; 16-21 years, 20·0% [4·3], 22·2 [10·0-49·3]; p<0·0001) and sex of the patients aged 10-21 years (girls 15·7% [2·5] vs boys 9·3% [1·7], 1·7 [1·2-2·4]; p=0·001). For patients aged 10 years and older with a rapid response to induction treatment, the use of alternate-week dexamethasone during phases of delayed intensification significantly reduced osteonecrosis incidence compared with continuous dexamethasone (8·7% [2·1] vs 17·0% [2·9], 2·1 [1·4-3·1]; p=0·0005), especially in those aged 16 years and older (11·3% [5·3] vs 37·5% [11·0], p=0·0003; girls 17·2% [8·1] vs 43·9% [14·1], p=0·05; boys 7·7% [5·9] vs 34·6% [11·6], p=0·0014). INTERPRETATION: Alternate-week dexamethasone during delayed intensification phases, a simple dose modification, reduces the risk of osteonecrosis in children and adolescents given intensified treatment for high-risk ALL. Its use is being evaluated in children with standard risk ALL. FUNDING: US National Cancer Institute at the National Institutes of Health.

Allogeneic hematopoietic stem cell transplantation for pediatric patients with treatment-related myelodysplastic syndrome or acute myelogenous leukemia.

The development of treatment-related myelodysplastic syndrome (tMDS) or treatment-related acute myelogenous leukemia (tAML) is a complication that can occur after chemotherapy or radiation therapy. Eighteen patients with a previous malignancy treated at our institution and three patients with a nonmalignant primary tumor received an allogeneic hematopoietic stem cell transplant (HSCT) on the pediatric bone marrow (BM) transplantation service for the treatment of tMDS/tAML over a 15-year period. Five patients proceeded to HSCT without induction chemotherapy. Fourteen patients received high-dose cytarabine according to the Capizzi II regimen as first-line induction therapy with 13 of them achieving complete remission (CR) or refractory anemia (RA) with persistent cytogenetic abnormalities after this treatment. Two patients received an anthracycline-based induction therapy. Conditioning regimens were selected according to previous therapies: 11 patients received busulfan-melphalan-fludarabine (BU-MEL-FLU), which consisted of busulfan (0.8 mg/kg/dose every 6 hours ×10 doses), melphalan (70 mg/m(2)/dose × two doses), and fludarabine (25 mg/m(2)/dose × five doses) for cytoreduction; three patients received a total body irradiation (TBI)-containing regimen; seven patients received myeloablative regimens containing busulfan and/or melphalan and/or thiotepa with doses modified for organ toxicity. Sixteen patients received T cell-depleted (TCD) grafts; four patients received unmodified grafts; one patient received a double-unit cord blood transplantation (DUCBT). Donors included HLA-matched (n = 9), or mismatched (n = 3) related donors, or HLA-matched (n = 4), or mismatched (n = 4) unrelated donors, or DUCBT (n = 1). Disease status at the time of HSCT was: morphologic and cytogenetic CR (n = 12); RA with positive cytogenetics (n = 6); and refractory disease (n = 3). With a median follow-up of 5.9 years (2.2-15.7 years), the 5-year overall survival (OS) and disease-free survival (DFS) rates for the entire group were 61.1% with 12 patients alive without evidence of either primary disease or tMDS/tAML. The OS and DFS rate for the 11 patients who received the BU-MEL-FLU cytoreduction with TCD grafts was 54.5%. DFS was 65.7% for patients in RA or CR at HSCT compared with 0% for patients with >5% residual marrow blasts (P = .015). Nine patients died; the cause of death was relapse of MDS/AML (n = 4) or primary disease (n = 2), graft-versus-host disease (GVHD; n = 2), and infection (n = 1). Four patients developed grade II to IV acute GVHD. One patient developed localized chronic GVHD. Our results suggest that the strategy of induction with high-dose cytarabine therapy followed by allogeneic stem cell transplantation improves the overall outcome for patients with tMDS/tAML. In addition, the use of a TCD transplantation with BU-MEL-FLU as cytoreduction may decrease the toxicity of transplantation in heavily pretreated patients without an increase in relapse rate.

Successful treatment of refractory metastatic histiocytic sarcoma with alemtuzumab.

BACKGROUND: Histiocytic sarcoma (HS) is an exceedingly rare tumor and carries a dismal prognosis when patients present with advanced-stage disease. Because of the poor response rates to conventional chemotherapy and the rarity of the disease, no standard of care exists for patients with HS. The authors report the single-agent use of the anti-CD52 antibody alemtuzumab in 2 patients who had advanced-stage HS. METHODS: Two patients with chemotherapy-refractory, metastatic HS with tumors that expressed the CD52 antigen received a prolonged course of treatment with the anti-CD52 monoclonal antibody alemtuzumab. RESULTS: Resected tumor samples from both patients demonstrated CD52 expression. Both patients had marked responses to single-agent alemtuzumab. One patient had a complete response with no evidence of disease for >5 years. The second patient had a major response to alemtuzumab and also remained alive with no evidence of disease for >4 years. CONCLUSIONS: Further studies need to be performed to examine CD52 expression and function in HS as well as the role of alemtuzumab in a larger cohort of patients. However, the clinical impact of single-agent alemtuzumab in the 2 patients described in this report was very encouraging. Given the toxicity and frequent inefficacy of conventional chemotherapy, patients with incompletely resected HS should be strongly considered for alemtuzumab therapy.

Clofarabine with topotecan, vinorelbine, and thiotepa reinduction regimen for children and young adults with relapsed AML.

Effective reinduction regimens are needed for children with relapsed and refractory acute myeloid leukemia (AML), as outcomes remain poor. Therapeutic options are limited in this heavily pretreated patient population, many of whom have reached lifetime recommended doses of anthracycline chemotherapy. The development of effective non-anthracycline-based salvage regimens is crucial to these patients who are at significant risk of life-threatening cardiotoxicity. We previously reported results of a phase 2 trial of a clofarabine-based regimen with topotecan, vinorelbine, and thiotepa (TVTC) in patients with relapsed acute leukemias. Here we report on an expanded bicenter cohort of 33 patients, <25 years of age, with relapsed/refractory AML treated with up to 2 cycles of the TVTC reinduction regimen from 2007 to 2018. The overall response rate, defined as complete remission or complete remission with partial recovery of platelet count, was 71.4% (95% confidence interval [CI], 41.9-91.6) for those patients in first relapse (n = 14) and 47.4% (95% CI, 24.4-71.1) for patients in second or greater relapse or with refractory disease. Responses were seen across multiple high-risk cytogenetic and molecular subtypes, with 84% of responders successfully bridged to allogeneic stem cell transplantation. The 5-year overall survival for patients in first relapse was 46.2% (95% CI, 19.1-73.3) and 50.0% (95% CI, 26.9-73.1) for patients who responded to TVTC. For pediatric and young adult patients with relapsed/refractory AML, TVTC reinduction compares favorably with currently used salvage regimens and warrants further exploration.

Impact of Bridging Chemotherapy on Clinical Outcomes of CD19-Specific CAR T Cell Therapy in Children/Young Adults with Relapsed/Refractory B Cell Acute Lymphoblastic Leukemia.

Chimeric antigen receptor (CAR) T cells achieve response and durable remission in patients with relapsed/refractory (R/R) B cell malignancies. Following collection of patient T cells, chemotherapy ("bridging chemotherapy") is utilized during the manufacture of CAR T cells. However, the optimal bridging chemotherapy has yet to be defined. Our objective in this study was to report clinical outcomes following bridging chemotherapy in a cohort of pediatric/young adult patients with R/R B cell acute lymphoblastic leukemia (B-ALL) treated with CAR T cell therapy. This retrospective study included patients enrolled on clinical trial NCT01860937 or referred to Memorial Sloan Kettering Cancer Center for commercial CAR T cell therapy (tisagenlecleucel). Bridging chemotherapy (given after T cell collection and before CAR T cell infusion) was defined as high intensity if myelosuppression was expected for >7 days. Outcome comparison analyses were performed in high-intensity versus low-intensity bridging chemotherapy, 1 cycle versus ≥2 cycles of bridging chemotherapy, disease burden at the start of bridging chemotherapy, disease burden at the start of bridging chemotherapy with chemotherapy intensity, tumor debulking by bridging chemotherapy, and disease burden pre-lymphodepleting chemotherapy (LDC) for CAR T cell treatment. The outcomes of this analysis showed that the incidence of grade ≥3 infection was significantly higher (94% versus 56%; P = .019) and overall survival (OS) was significantly lower (hazard ratio, 3.73; 95% confidence interval, 1.39 to 9.97; P = .006) in patients who received ≥2 cycles versus 1 cycle of bridging chemotherapy. No difference in incidence was found for cytokine release syndrome (P > .99) or neurotoxicity/immune effector cell-associated neurotoxicity syndrome (P = .70). Disease burden at the start of bridging chemotherapy, disease burden prior to LDC, and tumor debulking by bridging chemotherapy also did not significantly affect outcomes after CAR T cell therapy in this cohort. In this study, patients receiving ≥2 cycles of bridging chemotherapy had higher rates of infection and lower OS but no difference in CAR-specific toxicity. Clinicians should carefully consider the use of additional cycles of chemotherapy during the bridging period as it delays treatment with CAR T cells and increases the risk of infectious complications. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Effect of hemodialysis on the plasma levels of clofarabine.

Clofarabine, a nucleoside analogue for treatment of relapsed leukemia, is 50-60% excreted in urine. Clofarabine has not been studied in patients on hemodialysis. We measured levels in one patient in acute renal failure. Prior to dialysis, 43 hr after a 40 mg/m(2) infusion, plasma concentration was 139 ng/ml. One hour after beginning hemodialysis, a 20 mg/m(2) infusion began. Plasma concentrations were 84.2, 81.1, and 88.0 ng/ml while the dialysis and clofarabine infusion occurred simultaneously. Post-dialysis, while the clofarabine was still infusing, the level was 95.8 ng/ml. Hemodialysis does decrease clofarabine levels, but given its large volume distribution, hemodialysis may not be effective for clofarabine overdose.

Remission re-induction chemotherapy with clofarabine, topotecan, thiotepa, and vinorelbine for patients with relapsed or refractory leukemia.

BACKGROUND: We determined the maximum tolerated dose (MTD) of clofarabine when administered with topotecan, vinorelbine, thiotepa, and dexamethasone (TVTC) for children with relapsed or refractory acute leukemia, and observed the efficacy and toxicities of this therapy. PROCEDURE: Twelve patients with acute lymphoblastic or myeloblastic leukemia were given a 14-day remission induction therapy. Clofarabine was administered at a dose of 30 or 40 mg/m(2)/day over 2 hr for five consecutive days in six patients each. Patients who achieved a remission proceeded to a stem cell transplant (HSCT). A second cycle could be administered prior to HSCT. RESULTS: Of the six patients at the 30 mg/m(2) clofarabine dose, two achieved a complete response (CR) and one a PR and proceeded to BMT. Three patients had progressive disease. Five of the six patients at the 40 mg/m(2) achieved a CR. Four proceeded to HSCT, and one relapsed prior to HSCT. One patient died on day 45 with marrow hypoplasia without evidence of leukemia. Hematologic and infectious adverse events were universal. The one dose limiting non-infectious toxicity observed was prolonged marrow hypoplasia. CONCLUSION: TVTC has significant anti-leukemic activity in both acute lymphoblastic and myeloblastic leukemia. The MTD of clofarabine is 40 mg/m(2)/day in this combination. This is the recommended dose for the phase II study in patients with refractory or relapsed leukemia, a population which has limited therapeutic options.

Toll-like receptor 4 polymorphisms and risk of gram-negative bacteremia after allogeneic stem cell transplantation. A prospective pilot study.

The Toll-like receptor 4 (TLR4) gene is a major recognition receptor for lipopolysaccharide (LPS). In a pilot prospective study, we examined the association of 2 TLR4 polymorphisms (Asp299Gly and Thr399Ile) in the donor or the recipient with Gram-negative bloodstream infection (BSI) in 77 allogeneic hematopoietic stem cell transplant (HSCT) patients. Heterozygosity at both loci was defined as "risk genotype." The cumulative incidence of infection was estimated by treating death prior to infection as a competing risk event and compared between relevant groups using a modified chi-square test. Nine patients had the risk genotype based on donor and 5 based on recipient genotype data. Donor risk genotype showed marginal statistical significance (0.06) in univariate analysis, but not in multivariate analysis. A larger study is required to validate our findings and define genetic susceptibility to this serious infection in HSTC patients.