ALBERT

Description: Peripheral blood stem cells (PBSCs) are being used as an alternative to autologous marrow rescue for hematopoietic reconstitution after high- dose chemotherapy in patients with neuroblastoma and other solid malignancies. Use of PBSCs is preferred by some because of the belief that there is less risk of tumor contamination. Because tumor stem cell contamination is thought to be one contributing cause of relapse after myeloablative therapy and autologous reconstitution, we examined the potential risk of reinfusing circulating neuroblastoma cells by in vitro evaluation of their clonogenicity. Immunocytologic and tumor cell clonogenic analyses were performed on 74 blood samples obtained from 56 children with advanced-stage neuroblastoma. Concurrently drawn bone marrow specimens were evaluated in 30 instances. Circulating neoplastic cells were detected in 19 of 74 (26%) for all specimens and by immunologic techniques (26%). Using a clonogenic assay, 13 grew identifiable tumor colonies. Comparing results with the two techniques showed tumor colony growth in 10 of the 19 positive specimens by immunocytology. However, 3 of 53 samples (6%) that were negative by immunocytology were positive by the clonogenic assay. Of the 11 positive blood samples, 9 concurrent marrows contained neuroblastoma cells; of the 19 negative blood specimens, 3 concurrent marrows had metastatic disease. We conclude that circulating neuroblastoma cells are present in peripheral blood and have clonogenic properties in vitro. This supports the view that tumor cell contamination may well be one cause of relapse after autologous reconstitution. Consequently, PBSC collections should also undergo meticulous monitoring for tumor contamination before autologous reinfusion.

Description: Introduction: Event-free survival (EFS) for children with ALL is approximately 80%. Despite substantial success in achieving second and subsequent remissions, survival of patients with relapsed ALL (rALL) remains dismal. We propose that progress depends on identification of novel drug combinations with more activity in rALL than those commonly employed. The literature suggests a 40% CR rate for second and subsequent relapse (Br. J Haematol2005;131:579). However, CR rates depend on the number of prior therapeutic attempts and duration of any prior response, complicating identification of promising regimens. Limited patient numbers and a large number of potential candidate regimens discourage randomized trials. We surveyed local experience with rALL to establish a robust benchmark for evaluation of novel drug combinations. Methods: The TACL Consortium (www.tacl.us) was formed to develop novel drug combinations for patients with rALL. We initiated a review of all patients with rALL treated between 1995 and 2004 at eight TACL institutions. Detailed data on therapy, response, and duration of response were collected on all patients. Results: Of 313 rALL patients, 62% were males, 27% were older than 10 years at diagnosis, 26% had initial white blood counts (WBC) at diagnosis 〉=50,000/uL, and 46% were high-risk by NCI risk criteria. Re-induction attempts ranged between 1 and 9 and most commonly employed combinations of traditional ALL agents. Limiting analyses to patients with marrow involvement, we obtained 86% CR’s for 1st relapse (95% confidence interval 80%–90%), 44% for second relapse (35%–53%), and 30% for third relapse (19%–43%). CR rates declined with the number of prior treatment attempts (see Table, p

Description: Based on the recent reports that recombinant human granulocyte/macrophage colony-stimulating factor (rhGM-CSF) accelerates the rate of engraftment in a variety of autologous bone marrow transplantation settings, we have investigated its effects on hematopoietic recovery of patients with acute lymphoblastic leukemia (ALL) undergoing autologous bone marrow transplantation. Our studies, which involved 25 autologous ALL recipients who received rhGM-CSF and 27 controls similar for disease status (remission or relapse) and disease type (B- or T-lineage) differed from previous studies in one important aspect: the bone marrows were purged with 4- hydroperoxcyclophosphamide (4HC) and anti-T or anti-B-cell lineage- specific antibodies before transplantation. Such treatments frequently lead to a reduction in the CFU-GM content of the transplanted marrow. Eighteen of 25 patients completed the entire course of rhGM-CSF. Of the 16 patients who received greater than or equal to 64 micrograms/M2/d for at least eight days, there were five patients who had an apparent rhGM-CSF response and 11 patients who did not respond. Of the parameters analyzed, only the number of CFU-GM progenitor cells infused per kilogram was significantly associated with an rhGM-CSF response. All patients receiving greater than or equal to 1.2 x 10(4) CFU-GM progenitors per kilogram achieved an absolute neutrophil count (ANC) greater than or equal to 1,000/microL by day 21 and had a greater than 50% decrement in ANC within 48 to 72 hours of discontinuing rhGM-CSF, as contrasted to none of the patients receiving less than or equal to 7.2 x 10(3) CFU-GM progenitors per kilogram.(ABSTRACT TRUNCATED AT 250 WORDS)

Description: Background: Approximately 3540 children are diagnosed with leukemia in the United States yearly (Bhatia and Robison, Oncology of Infancy and Childhood, 2008). Cooperative group trials have increased survival, particularly for acute lymphoblastic leukemia (ALL), but successful treatment of recurrent leukemia remains an unmet medical need. Resistance pathways and epigenetic alterations suggest a role for histone deacetylase (HDAC) inhibitors in children with leukemia (Burke and Bhatla, Frontiers in Pediatrics, 2014). Panobinostat is an orally administered pan-deacetylase inhibitor with activity against HDACs at concentrations in the nanomolar range (Atadja, Cancer Letters, 2009), and for which there is pre-clinical evidence of activity in pediatric leukemia (Stubbs, et al., ASH 2010). Panobinostat shows promise in a variety of adult hematologic malignancies (Khot et al., Expert Opinion on Investigational Drugs, 2013). We undertook a phase I trial of panobinostat in children with recurrent hematologic malignancies, and herein report the safety and pharmacokinetics (PK) from enrolled children with leukemia. Methods: T2009-012 is a first-in-child study coordinated by Therapeutic Advances in Childhood Leukemia and Lymphoma (TACL). Children with relapsed or refractory leukemia between the ages of 1 and 21 years were enrolled to a multi-center, single agent trial of panobinostat dosed once per day three days per week for four successive weeks. Dose escalation was a standard 3+3 design with three dose levels planned. Subjects underwent lumbar puncture with prophylactic chemotherapy at treatment start and after a 28 day course. Blood was sampled pre-dose, at 0.5, 1, 6, 24 and 28-48 hours following the first dose. PK was obtained from blood on patients concurrently with optional specimens obtained from cerebrospinal fluid (CSF) on Day 29. Subjects who received fewer than 11 of the 12 planned doses and did not experience a dose limiting toxicity (DLT) were considered not evaluable for DLT, but were included in the summary of toxicities. Serial ECGs were monitored. Results: Seventeen subjects were enrolled with a diagnosis of acute leukemia, 10 with ALL and 7 with acute myelogenous leukemia (AML). Five were enrolled at dose level 1, 24 mg/m2/dose, 6 at dose level 2, 30 mg/m2/dose, and 6 at dose level 3, 34 mg/m2/dose. There have been no DLTs. Nine subjects are evaluable for DLT and 4 subjects were taken off study early due to increasing blast count. No subjects required removal from protocol therapy for QTc prolongation. One subject with infant ALL was removed early for progressive Aspergillus infection, 1 subject only received 10 doses owing to electrolyte abnormalities, and 2 subjects had nausea and vomiting after administration of 4 doses and did not continue. Grade 3/4 adverse events occurring in more than 20% of subjects included anemia in 82%, diarrhea in 24%, febrile neutropenia in 65%, hypokalemia in 41%, and hypophosphatemia in 24%. Concentration-time profiles were obtained from 9 subjects ages 16 months to 14 years in the 3 dose levels. Mean ± SE of PK for all subjects were Cmax 28.8 ± 6.1 ng/mL, Tmax 2.0 ± 0.8 hours, and T1/2 12.8 ± 3.0 hours. Two toddlers had the highest dose-normalized AUC0-inf and lowest oral clearance. Apparent oral clearance proportionally increased with increase in BSA. To date, 4 CSF specimens have been evaluated and found to have panobinostat below the lower limit of the quantification of 0.1 ng/mL, despite appreciable levels in the plasma. Two subjects on dose level two began a second cycle of therapy; one completed a second cycle for MLL rearranged leukemia and one discontinued study participation in the second cycle to undergo hematopoietic stem cell transplant for secondary AML after achieving a CRp in the first cycle. Conclusions: Panobinostat was tolerated these heavily pre-treated patients without unanticipated toxicities. PK in larger children and adults appears similar but PK in smaller children needs to be further explored. Penetration of panobinostat into the CSF was negligible. Two of 17 patients were able to receive a second cycle of therapy, but 4 had to be withdrawn early because of rapid increase in blast counts. Future trials will explore combination therapy in children with refractory hematologic malignancies, particularly those known to be driven by epigenetic mechanisms, in order to better control risk of rapid progression and improve efficacy through synergy. Disclosures Off Label Use: panobinostat for leukemia. Manley:Seattle Genetics, Inc.: Employment, Equity Ownership. Thomson:Epizyme, Inc: Employment.

Description: The outcome of relapsed ALL remains very poor, and many re-induction regimens are highly toxic. We report here the Phase I component of a Phase I/II study of bortezomib added to 4-drug induction with vincristine, dexamethasone, pegylated asparaginase, and doxorubicin in children with relapsed ALL. A total of 10 patients were enrolled, 5 in 1st marrow relapse (2 early and 3 late relapses) and 5 in 2nd or subsequent relapse. Four patients were enrolled at dose level 1 (1 mg/m2) to obtain 3 evaluable patients. One patient was inevaluable for toxicity because of an error in dexamethasone doses and was removed after 8 days. No dose-limiting toxicity (DLT) was observed. Six patients were enrolled at dose level 2 (1.3 mg/m2), the standard single agent dose. One patient had a DLT (hypophosphatemia and rhabdomyolysis) after1 dose of bortezomib, and that patient died from diffuse zygomyces infection by day 17. Five additional patients were enrolled with no further DLT’s. As planned, no further dose escalation was pursued. The regimen had predictable toxicity related to the chemotherapy drugs. Only 2 patients had mild peripheral neuropathy (grades 1 and 2). Seven of the10 patients (70%) achieved a CR, and 1/10 had bone marrow CR with persistent central nervous system (CNS) leukemia despite weekly intrathecal (IT) methotrexate, for a total of 80% bone marrow CR rate. In conclusion: the combination of bortezomib with 4 standard drugs is highly active with acceptable toxicity in heavily pretreated relapsed pediatric ALL patients. We are expanding the MTD cohort for a phase II estimate, and intend to report updated results at the ASH meeting. Day 1 2 4 8 11 14 15 18 22 29 - 35 Bortezomib (1 or 1.3 mg/m2) B B B B Evaluate Vincristine (1.5 mg/m2) V V V V Doxorubicin (60 mg/m2) Dox Dexamethasone (10 mg/m2) x 14 days —— —— —— —— —— —〉 PEG-Asparaginase (2500 U/ m2) PEG PEG PEG PEG IT Ara-C ITA CNS Negative: IT Methotrexate ITM CNS Positive: IT Triples ITT ITT ITT

Description: Based on the recent reports that recombinant human granulocyte/macrophage colony-stimulating factor (rhGM-CSF) accelerates the rate of engraftment in a variety of autologous bone marrow transplantation settings, we have investigated its effects on hematopoietic recovery of patients with acute lymphoblastic leukemia (ALL) undergoing autologous bone marrow transplantation. Our studies, which involved 25 autologous ALL recipients who received rhGM-CSF and 27 controls similar for disease status (remission or relapse) and disease type (B- or T-lineage) differed from previous studies in one important aspect: the bone marrows were purged with 4- hydroperoxcyclophosphamide (4HC) and anti-T or anti-B-cell lineage- specific antibodies before transplantation. Such treatments frequently lead to a reduction in the CFU-GM content of the transplanted marrow. Eighteen of 25 patients completed the entire course of rhGM-CSF. Of the 16 patients who received greater than or equal to 64 micrograms/M2/d for at least eight days, there were five patients who had an apparent rhGM-CSF response and 11 patients who did not respond. Of the parameters analyzed, only the number of CFU-GM progenitor cells infused per kilogram was significantly associated with an rhGM-CSF response. All patients receiving greater than or equal to 1.2 x 10(4) CFU-GM progenitors per kilogram achieved an absolute neutrophil count (ANC) greater than or equal to 1,000/microL by day 21 and had a greater than 50% decrement in ANC within 48 to 72 hours of discontinuing rhGM-CSF, as contrasted to none of the patients receiving less than or equal to 7.2 x 10(3) CFU-GM progenitors per kilogram.(ABSTRACT TRUNCATED AT 250 WORDS)

Description: Abstract 497 DS is associated with a high incidence of ALL that is linked to unique biological and clinical features. In some studies these children have had an inferior outcome and have demonstrated unusual sensitivity to the side effects of chemotherapy, particularly methotrexate (MTX). CCG-1991 aimed to: 1) determine in a randomized fashion the benefit of double delayed intensification (DI) over single DI in a modified BFM therapy that uses dexamethasone as the sole corticosteroid and 2) compare the outcome of treatment that included escalating-dose intravenous (IV) MTX without leucovorin, and vincristine, to one that contains oral (PO) MTX, mercaptopurine, vincristine and dexamethasone during the interim maintenance phases (IM) of therapy. Patients received a 3-drug induction with vincristine, pegylated asparaginase, dexamethasone, and intrathecal cytarabine and MTX. This was followed by consolidation, delayed intensification, interim maintenance, and maintenance phases of therapy. Slow early responders by bone marrow morphology (Day 7/14 M3-M3, or M3-M2; or M2 at Day 28 Induction) and patients with unfavorable cytogenetics [(t(9;22)(q34;q11), (4;11)(q21;q23), balanced t(1;19)(q23;p13) or hypodiploidy with 〈 45 chromosomes] were non-randomly assigned to a COG augmented BFM therapy regimen (N Engl J Med 1998; 338:1663). Rapid early responders with no unfavorable cytogenetics or CNS leukemia were randomized in a 2 × 2 factorial design to one of the 4 regimens -Table 1. Three thousand fifty four children with NCI SR ALL were enrolled on CCG-1991; 2078 non-T ALL eligible patients were randomized. A total of 108 patients with DS were enrolled, 77 patients were randomized to one of the 4 regimens; 45 patients were randomized to the arms containing PO MTX during IM (OS+OD), and 32 to the ones containing IV MTX (IS+ID) during IM. IV methotrexate, as given in this study, was generally well tolerated, but the mean total dose was lower in patients with DS. There was no increased hepatic toxicity, seizures or leukoencephalopathy in patients with DS during IM on either the IV or PO MTX arms, as compared to those without DS. Similarly, the incidence of systemic infections was not higher in patients with DS. The incidence of mucositis, however, was increased in patients with DS as compared with patients without DS, particularly in those who received IV MTX. Five-year EFS and overall survival (OS) for patients with DS randomized to the IV MTX and PO MTX arms are listed in Table 2. The overall 5-year EFS and OS of randomized patients with DS are 90.1% ± 4.9% and 94.8% ± 3.7% respectively. We conclude that patients with DS and SR-ALL without adverse features can be cured with COG BFM-modified therapy with escalating-dose IV MTX without leucovorin rescue during the interim phases of therapy. Disclosure: Matloub: Bristol-Myers Squibb: Previous employment.

Description: Abstract 320 Three thousand fifty four children with NCI standard-risk (SR) ALL were enrolled on CCG-1991; 2075 non-T ALL eligible patients were randomized and began treatment with IT cytarabine, vincristine, dexamethasone, and pegylated asparaginase. Bone marrow status was assessed at Day 7, 14, and 28 of Induction. Slow early responders (Day 7/14 M3-M3 and M3-M2; or M2 at Day 28 Induction) and patients with unfavorable cytogenetics were non-randomly assigned to a COG augmented BFM therapy regimen (N Engl J Med 1998; 338:1663).Thirteen hundred and thirty patients were analyzed for the presence of trisomy 4 and trisomy 10 (DT); and 1041 patients were evaluated for the presence of TEL/AML1 (ETV6/RUNX1) (TEL) fusion transcript. Twenty four percent of patients were positive for DT, and 41% were positive for TEL. Among the randomized subset, 23.8% had DT, and 40.8% had TEL. Six year event-free survival (EFS) and overall survival (OS) rates are given in the tables below for all patients and also separately for the randomized patients, by DT and TEL status. There was a significant different in EFS and OS between patients that were DT+ vs. DT- and also between patients that were TEL+ vs. TEL-.The overall 6-year EFS and OS for all patients with B-lineage ALL are 88.1±1.1% and 94.7±0.8%; and for the randomized patients they are 89.4±2.4% and 95.9±0.8%. We conclude that COG risk-adapted therapy is curative for patients with NCI-SR criteria and DT and/or TEL. Disclosures: No relevant conflicts of interest to declare.

Description: Background: Adequateexposure to oral 6MP during maintenance is critical to sustain durable remissions. We have previously shown that poor systemic exposure to 6MP (as measured by poor adherence to oral 6MP) is associated with increased risk of relapse (JCO 30[17]:2094-101; Blood 124[15]:2345-53). Accurate assessment of 6MP intake is therefore critical to ensure timely interventions. Self-report is a convenient and inexpensive method to monitor 6MP intake in the clinical setting; however, literature in the non-oncology setting indicates that self-report is subject to over-reporting, and the extent of over-reporting is directly related to the number of missed doses. The accuracy of self/parent-report of 6MP intake during ALL maintenance is not known. We address this issue by comparing self-reported 6MP intake to electronic monitoring, and identify predictors of over-reporting of prescribed 6MP intake. Methods: Participants included 416 children with ALL in first remission receiving oral 6MP (75 mg/m2/d) during maintenance. 6MP intake was measured electronically using the Medication Event Management System (MEMS - objective record), which recorded the dates/times of each 6MP bottle opening over 4 study months per patient (28 days/month). The patient (or parent if MEMS report: ≥5 days/month for 〉50% of study months) and "others." Logistic regression examined characteristics (age at study, sex, race/ ethnicity, 6MP non-adherence [MEMs-based adherence rate