Nelarabine, etoposide, and cyclophosphamide in relapsed pediatric T-acute lymphoblastic leukemia and T-lymphoblastic lymphoma (study T2008-002 NECTAR).

Children with relapse of T-cell acute lymphoblastic leukemia (T-ALL) or lymphoblastic lymphoma (T-LBL) have a dismal prognosis, largely due to difficulty attaining second remission. We hypothesized that adding etoposide and cyclophosphamide to the nucleoside analog nelarabine could improve response rates over single-agent nelarabine for relapsed T-ALL and T-LBL. This phase I dose-escalation trial's primary objective was to evaluate the dose and safety of nelarabine given in combination with etoposide at 100 mg/m2 /day and cyclophosphamide at 330-400 mg/m2 /day, each for 5 consecutive days in children with either T-ALL (13 patients) or T-LBL (10 patients). Twenty-three patients were treated at three dose levels; 21 were evaluable for dose-limiting toxicities (DLT) and response. The recommended phase II doses (RP2D) for this regimen, when given daily ×5 every 3 weeks, were nelarabine 650 mg/m2 /day, etoposide 100 mg/m2 /day, and cyclophosphamide 400 mg/m2 /day. DLTs included peripheral motor and sensory neuropathies. An expansion cohort to evaluate responses at the RP2D was terminated early due to slow accrual. The overall best response rate was 38% (8/21), with 33% (4/12) responses in the T-ALL cohort and 44% (4/9) responses in the T-LBL cohort. These response rates are comparable to those seen with single-agent nelarabine in this setting. These data suggest that the addition of cyclophosphamide and etoposide to nelarabine does not increase the incidence of neurologic toxicities or the response rate beyond that obtained with single-agent nelarabine in children with first relapse of T-ALL and T-LBL.

Temsirolimus combined with cyclophosphamide and etoposide for pediatric patients with relapsed/refractory acute lymphoblastic leukemia: a Therapeutic Advances in Childhood Leukemia Consortium trial (TACL 2014-001).

Phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling is commonly dysregulated in acute lymphoblastic leukemia (ALL). The TACL2014-001 phase I trial of the mTOR inhibitor temsirolimus in combination with cyclophosphamide and etoposide was performed in children and adolescents with relapsed/refractory ALL. Temsirolimus was administered intravenously (IV) on days 1 and 8 with cyclophosphamide 440 mg/m2 and etoposide 100 mg/m2 IV daily on days 1-5. The starting dose of temsirolimus was 7.5 mg/m2 (DL1) with escalation to 10 mg/m2 (DL2), 15 mg/m2 (DL3), and 25 mg/m2 (DL4). PI3K/mTOR pathway inhibition was measured by phosphoflow cytometry analysis of peripheral blood specimens from treated patients. Sixteen heavily-pretreated patients were enrolled with 15 evaluable for toxicity. One dose-limiting toxicity of grade 4 pleural and pericardial effusions occurred in a patient treated at DL3. Additional dose-limiting toxicities were not seen in the DL3 expansion or DL4 cohort. Grade 3/4 non-hematologic toxicities occurring in three or more patients included febrile neutropenia, elevated alanine aminotransferase, hypokalemia, mucositis, and tumor lysis syndrome and occurred across all doses. Response and complete were observed at all dose levels with a 47% overall response rate and 27% complete response rate. Pharmacodynamic correlative studies demonstrated dose-dependent inhibition of PI3K/mTOR pathway phosphoproteins in all studied patients. Temsirolimus at doses up to 25 mg/m2 with cyclophosphamide and etoposide had an acceptable safety profile in children with relapsed/refractory ALL. Pharmacodynamic mTOR target inhibition was achieved and appeared to correlate with temsirolimus dose. Future testing of next-generation PI3K/mTOR pathway inhibitors with chemotherapy may be warranted to increase response rates in children with relapsed/refractory ALL.

Survival of pediatric Hodgkin lymphoma patients treated with doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide (ABVE-PC) versus doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) at a single institution.

BACKGROUND: Adriamycin, bleomycin, vinblastine, dacarbazine (ABVD), the de facto standard of care in adult-onset Hodgkin lymphoma (HL), has not been directly compared to doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide (ABVE-PC), a pediatric-aimed regimen designed to reduce late effects. We aimed to describe the single-institution experience of using both regimens in patients with pediatric HL. METHODS: This retrospective cohort study evaluated a total of 224 patients diagnosed with HL between 1999 and 2018 at Children's Hospital Los Angeles (CHLA), of which 93 patients were eligible having received ABVD (n = 46) or ABVE-PC (n = 47) chemotherapy as their initial treatment. Descriptive analyses were performed using the Student's t-test or Fisher's exact test. Survival analysis used the Kaplan-Meier method. Events included death, relapse, and secondary malignancy. We also describe the use of radiation therapy, pulmonary toxicity, and cardiomyopathy determined by shortening fraction <29%. Analyses followed an intention-to-treat principle. RESULTS: There was no difference in baseline characteristics between the patients receiving ABVE-PC or ABVD in regard for stage, risk group, or prognostic variables, such as the presence or absence of "B" symptoms, bulky disease, and extra-nodal involvement. A greater proportion of patients treated with ABVE-PC received consolidating external beam radiation treatment (XRT) either by randomization or by response compared to ABVD (59.6% vs. 32.6%, respectively, p = .01). While not statistically significant, response to therapy, assessed by positron emission tomography/computerized tomography (PET/CT) where available, mirrored the use for radiation (rapid response 58.3% vs. 90.0%, n = 34, p = .11). The median dose of anthracycline (doxorubicin) was the same in patients receiving ABVE-PC versus ABVD (200 vs. 200 mg/m2 , interquartile range 200-250 vs. 200-300 mg/m2 , p = .002). There was no difference in event-free survival (p = .63) or overall survival (p = .37) with a median follow-up length of 3.9 years. CONCLUSIONS: ABVD and ABVE-PC achieved similar survival outcomes in our single-institution cohort.

Acute myeloid leukemia with t(X;6)9p11;q23);MYB-GATA1 and female sex: GATA1 insufficiency may be insufficient for pathogenesis.

Pediatric acute myeloid leukemia (AML) is genetically heterogenous (Olsson et al., 2016). t(X;6)(p11;q23) is a rare but recurrent chromosomal translocation in infant AML thought to be associated with male sex and basophilic differentiation (Dastugue et al., 1997). Here we report molecular characterization of AML with t(X;6)(p11;q23);MYB-GATA1 in two female infants and demonstrate preserved GATA1 expression in the sample tested. These findings further debunk a concept that this fusion was restricted to males, in whom it disrupts the only copy of the X-linked GATA1 gene, causing presumable complete loss of GATA1 function. Our data also demonstrate the power and efficiency of RNA sequencing for subclassification of leukemia on a clinically relevant timeline.

A phase I study of panobinostat in children with relapsed and refractory hematologic malignancies.

Background: Panobinostat demonstrates activity against pediatric cancers in vitro. A phase I trial in children with refractory hematologic malignancies was conducted. Study design: The trial evaluated two schedules of oral panobinostat using 3 + 3 dose escalations in 28-day cycles. For children with leukemia, panobinostat was given once daily three days a week each week at 24, 30 and 34 mg/m2/day. For children with lymphoma, panobinostat was given once daily three days a week every other week at 16, 20 and 24 mg/m2/day. Cerebrospinal fluid (CSF) from Day 29 of the first cycle, when available, was evaluated for PK. The study was registered on clinicaltrials.gov (NCT01321346) Results: Twenty-two subjects enrolled with leukemia. Five enrolled at dose level 1, 6 at dose level 2, and 11 at dose level 3. There was one dose limiting toxicity (DLT) in the leukemia arm at dose level 3 (Grade 4 hypertriglyceridemia), but no maximum tolerated dose (MTD) was identified. No subjects required removal from protocol therapy for QTc prolongation. PK studies were available in 11 subjects with similar exposure in children as in adults. Four Day 29 CSF specimens were found to have panobinostat levels below the lower limit of quantification. Five subjects with lymphoma were enrolled and received study drug, and 4 were evaluable for DLT. A DLT was reported (Grade 3 enteritis) on the lymphoma arm. Conclusions: Panobinostat was tolerated in heavily pretreated pediatric subjects. Gastrointestinal effects were observed on this study. There were no cardiac findings. There were no responses.

Decitabine and Vorinostat with Chemotherapy in Relapsed Pediatric Acute Lymphoblastic Leukemia: A TACL Pilot Study.

PURPOSE: Treatment failure from drug resistance is the primary reason for relapse in acute lymphoblastic leukemia (ALL). Improving outcomes by targeting mechanisms of drug resistance is a potential solution. PATIENTS AND METHODS: We report results investigating the epigenetic modulators decitabine and vorinostat with vincristine, dexamethasone, mitoxantrone, and PEG-asparaginase for pediatric patients with relapsed or refractory B-cell ALL (B-ALL). Twenty-three patients, median age 12 years (range, 1-21) were treated in this trial. RESULTS: The most common grade 3-4 toxicities included hypokalemia (65%), anemia (78%), febrile neutropenia (57%), hypophosphatemia (43%), leukopenia (61%), hyperbilirubinemia (39%), thrombocytopenia (87%), neutropenia (91%), and hypocalcemia (39%). Three subjects experienced dose-limiting toxicities, which included cholestasis, steatosis, and hyperbilirubinemia (n = 1); seizure, somnolence, and delirium (n = 1); and pneumonitis, hypoxia, and hyperbilirubinemia (n = 1). Infectious complications were common with 17 of 23 (74%) subjects experiencing grade ≥3 infections including invasive fungal infections in 35% (8/23). Nine subjects (39%) achieved a complete response (CR + CR without platelet recovery + CR without neutrophil recovery) and five had stable disease (22%). Nine (39%) subjects were not evaluable for response, primarily due to treatment-related toxicities. Correlative pharmacodynamics demonstrated potent in vivo modulation of epigenetic marks, and modulation of biologic pathways associated with functional antileukemic effects. CONCLUSIONS: Despite encouraging response rates and pharmacodynamics, the combination of decitabine and vorinostat on this intensive chemotherapy backbone was determined not feasible in B-ALL due to the high incidence of significant infectious toxicities. This study is registered at http://www.clinicaltrials.gov as NCT01483690.

Excellent long-term survival of children with Down syndrome and standard-risk ALL: a report from the Children's Oncology Group.

The Children's Cancer Group 1991 study was a clinical trial for children with National Cancer Institute standard-risk acute lymphoblastic leukemia (ALL). This trial demonstrated that 5 doses of vincristine and escalating IV methotrexate (MTX) without leucovorin rescue in the interim maintenance (IM) phases resulted in superior event-free survival (EFS) when compared with 2 doses of vincristine, oral (PO) MTX, PO mercaptopurine, and dexamethasone. This report describes a favorable outcome of this regimen in patients with Down syndrome (DS). Forty-four patients with DS were randomized to the arms containing PO MTX during IM, and 31 to those containing IV MTX. Ten-year EFS rates for patients with DS randomized to IV MTX vs PO MTX were 94.4% ± 5.4% vs 81.5% ± 6.6%, respectively. IV methotrexate with strict escalation parameters, as given in this study, was well tolerated, although the mean total tolerated dose received was lower in patients with DS than in those without DS. There was no increase in hepatic toxicity, systemic infections, or treatment-related deaths in patients with DS during IM on either the IV or PO MTX arms, as compared with those without DS. The incidence of mucositis was increased in patients with DS as compared with patients without DS, particularly among patients who received IV MTX. This trial was registered at www.clinicaltrials.gov as #NCT00005945.

Treatment of higher risk acute lymphoblastic leukemia in young people (CCG-1961), long-term follow-up: a report from the Children's Oncology Group.

Children's Cancer Group CCG-1882 improved outcome for 1-21-year old with high risk acute lymphoblastic leukemia and Induction Day 8 marrow blasts ≥25% (slow early responders, SER) with longer and stronger post induction intensification (PII). This CCG-1961 explored alternative PII strategies. We report 10-year follow-up for patients with rapid early response (RER) and for the first time details our experience for SER patients. A total of 2057 patients were enrolled, and 1299 RER patients were randomized to 1 of 4 PII regimens: standard vs. augmented intensity and standard vs. increased length. At the end of interim maintenance, 447 SER patients were randomized to idarubicin/cyclophosphamide or weekly doxorubicin in the delayed intensification phases. The 10-year EFS for RER were 79.4 ± 2.4% and 70.9 ± 2.6% (hazard ratio = 0.65, 95% CI 0.52-0.82, p < 0.001) for augmented and standard strength PII; the 10-year OS rates were 87.2 ± 2.0% and 81.0 ± 2.2% (hazard ratio = 0.64, 95% CI 0.48-0.86, p = 0.003). Outcomes remain similar for standard and longer PII, and for SER patients assigned to idarubicin/cyclophosphamide and weekly doxorubicin. The EFS and OS advantage of augmented PII is sustained at 10 years for RER patients. Longer PII for RER patients and sequential idarubicin/cyclophosphamide for SER patients offered no advantage. CCG-1961 is the platform for subsequent COG studies.

Improved Survival for Children and Young Adults With T-Lineage Acute Lymphoblastic Leukemia: Results From the Children's Oncology Group AALL0434 Methotrexate Randomization.

PURPOSE: Early intensification with methotrexate (MTX) is a key component of acute lymphoblastic leukemia (ALL) therapy. Two different approaches to MTX intensification exist but had not been compared in T-cell ALL (T-ALL): the Children's Oncology Group (COG) escalating dose intravenous MTX without leucovorin rescue plus pegaspargase escalating dose, Capizzi-style, intravenous MTX (C-MTX) regimen and the Berlin-Frankfurt-Muenster (BFM) high-dose intravenous MTX (HDMTX) plus leucovorin rescue regimen. PATIENTS AND METHODS: COG AALL0434 included a 2 × 2 randomization that compared the COG-augmented BFM (ABFM) regimen with either C-MTX or HDMTX during the 8-week interim maintenance phase. All patients with T-ALL, except for those with low-risk features, received prophylactic (12 Gy) or therapeutic (18 Gy for CNS3) cranial irradiation during either the consolidation (C-MTX; second month of therapy) or delayed intensification (HDMTX; seventh month of therapy) phase. RESULTS: AALL0434 accrued 1,895 patients from 2007 to 2014. The 5-year event-free survival and overall survival rates for all eligible, evaluable patients with T-ALL were 83.8% (95% CI, 81.2% to 86.4%) and 89.5% (95% CI, 87.4% to 91.7%), respectively. The 1,031 patients with T-ALL but without CNS3 disease or testicular leukemia were randomly assigned to receive ABFM with C-MTX (n = 519) or HDMTX (n = 512). The estimated 5-year disease-free survival ( P = .005) and overall survival ( P = .04) rates were 91.5% (95% CI, 88.1% to 94.8%) and 93.7% (95% CI, 90.8% to 96.6%) for C-MTX and 85.3% (95% CI, 81.0%-89.5%) and 89.4% (95% CI, 85.7%-93.2%) for HDMTX. Patients assigned to C-MTX had 32 relapses, six with CNS involvement, whereas those assigned to HDMTX had 59 relapses, 23 with CNS involvement. CONCLUSION: AALL0434 established that ABFM with C-MTX was superior to ABFM plus HDMTX for T-ALL in approximately 90% of patients who received CRT, with later timing for those receiving HDMTX.

Myeloid lineage switch following chimeric antigen receptor T-cell therapy in a patient with TCF3-ZNF384 fusion-positive B-lymphoblastic leukemia.

A pediatric patient diagnosed initially with B-lymphoblastic leukemia (B-ALL) relapsed with lineage switch to acute myeloid leukemia (AML) after chimeric antigen receptor T-cell (CAR-T) therapy and hematopoietic stem cell transplant. A TCF3-ZNF384 fusion was identified at diagnosis, persisted through B-ALL relapse, and was also present in the AML relapse cell population. ZNF384-rearrangements define a molecular subtype of B-ALL characterized by a pro-B-cell immunophenotype; furthermore, ZNF384-rearrangements are prevalent in mixed-phenotype acute leukemias. Lineage switch following CAR-T therapy has been described in patients with KMT2A (mixed lineage leukemia) rearrangements, but not previously in any patient with ZNF384 fusion.

First pediatric experience of SL-401, a CD123-targeted therapy, in patients with blastic plasmacytoid dendritic cell neoplasm: report of three cases.

BACKGROUND: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a highly aggressive hematological malignancy with extremely poor outcome. The median overall survival for adult patients is 9-13 months. Pediatric patients are exceedingly rare with an unclear clinical course. Currently, no standardized therapy has been established, although an acute lymphoblastic leukemia type of treatment appears to be more effective in those patients who are able to tolerate aggressive chemotherapy. SL-401 is a targeted therapy directed to CD123, a protein ubiquitously expressed at high level on the surface of BPDCN blasts. In adult phase 2 trials, it has demonstrated efficacy with 90% overall response rate. No pediatric patients with BPDCN using SL-401 have been reported. CASE PRESENTATION: Here, we report the first pediatric experience of three children with BPDCN treated with SL-401 at our institution. All patients tolerated SL-401 without significant toxicities. One patient with multiply relapsed and refractory disease had no response. The other two cases had significant and rapid clinical improvement after the two courses of treatment. However, the response was transient, and growth of soft tissue mass was observed in-between cycles in both patients with large tumor burden. CONCLUSIONS: This is the first report of SL-401 in pediatric patients with BPDCN. Sl-401 was well tolerated and can produce a promising response. Further testing this agent in children is warranted.

Outcome of children with multiply relapsed B-cell acute lymphoblastic leukemia: a therapeutic advances in childhood leukemia & lymphoma study.

The survival of pediatric patients with multiply relapsed and/or refractory (R/R) B-cell acute lymphoblastic leukemia has historically been very poor; however, data are limited in the current era. We conducted a retrospective study to determine the outcome of multiply R/R childhood B-ALL treated at 24 TACL institutions between 2005 and 2013. Patient information, treatment, and response were collected. Prognostic factors influencing the complete remission (CR) rate and event-free survival (EFS) were analyzed. The analytic set included 578 salvage treatment attempts among 325 patients. CR rates (mean ± SE) were 51 ± 4% for patients with bone marrow R/R B-ALL who underwent a second salvage attempt, 37 ± 6% for a third attempt, and 31 ± 6% for the fourth through eighth attempts combined. For patients achieving a CR after their second, third, and fourth through eighth attempts, the 2 year EFS was 41 ± 6%, 13 ± 7%, and 27 ± 13% respectively. Our results showed slight improvement when compared to previous studies. This is the largest and most recent study to date that evaluates the outcome of this patient population. Our data will provide detailed reference for the evaluation of new agents being developed for childhood B-ALL.

Redefining treatment failure for pediatric acute leukemia in the era of minimal residual disease testing.

Technologies for the detection of minimal residual disease (MRD) in leukemia and our understanding of the prognostic implications of MRD at different phases of treatment have significantly improved over the past decade. As a result, definitions of treatment failure based on bone marrow morphology by light microscopy are becoming increasingly inadequate for clinical care and trial design. In addition, novel therapies that may have increased efficacy and decreased toxicity in the setting of MRD compared to overt disease are changing clinical practice and challenging investigators to redefine treatment failure, the role of disease surveillance in remission, and clinical trial eligibility in the era of MRD.