Tanya M. Trippett

Phase I Pharmacokinetic and Pharmacodynamic Study of 17-N-Allylamino-17-Demethoxygeldanamycin in Pediatric Patients with Recurrent or Refractory Solid Tumors: A Pediatric Oncology Experimental Therapeutics Investigators Consortium Study

Purpose: Heat shock protein 90 (Hsp90) is essential for the posttranslational control of many regulators of cell growth, differentiation, and apoptosis. 17-N-Allylamino-17-demethoxygeldanamycin (17-AAG) binds to Hsp90 and alters levels of proteins regulated by Hsp90. We conducted a phase I trial of 17-AAG in pediatric patients with recurrent or refractory neuroblastoma, Ewings sarcoma, osteosarcoma, and desmoplastic small round cell tumor to determine the maximum tolerated dose, define toxicity and pharmacokinetic profiles, and generate data about molecular target modulation. Experimental Design: Escalating doses of 17-AAG were administered i.v. over 1 to 2 h twice weekly for 2 weeks every 21 days until patients experienced disease progression or toxicity. harmacokinetic and pharmacodynamic studies were done during cycle 1. Results: Fifteen patients were enrolled onto dose levels between 150 and 360 mg/m2; 13 patients were evaluable for toxicity. The maximum tolerated dose was 270 mg/m2. DLTs were grade 3 transaminitis and hypoxia. Two patients with osteosarcoma and bulky pulmonary metastases died during cycle 1 and were not evaluable for toxicity. No objective responses were observed. 17-AAG pharmacokinetics in pediatric patients were linear; clearance and half-life were 21.6 ± 6.21 (mean ± SD) L/h/m2 and 2.6 ± 0.95 h, respectively. Posttherapy increases in levels of the inducible isoform of Hsp70, a marker of target modulation, were detected in peripheral blood mononuclear cells at all dose levels. Conclusion: 17-AAG was well tolerated at a dose of 270 mg/m2 administered twice weekly for 2 of 3 weeks. Caution should be used in treatment of patients with bulky pulmonary disease.

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 Hodgkins 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 Hodgkins 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 Hodgkins 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 Hodgkins lymphoma achieving PET-negativity, and therefore could optimise the chance of cure after HDT/ASCT. FUNDING Seattle Genetics.

Irinotecan for pediatric solid tumors: the Memorial Sloan-Kettering experience.

Purpose Irinotecan is a novel antineoplastic agent that works by inhibiting the enzyme, topoisomerase 1. Although not extensively studied in children, preclinical studies and several phase 1 trials indicate activity against a variety of relapsed solid tumors when administered on a protracted schedule. This report describes an institutional experience with irinotecan for the treatment of pediatric solid tumors. Patients and Methods Twenty-two heavily pretreated children with multiply relapsed tumors were treated with courses of irinotecan at 20 mg/m2 per day for 10 days [(every day × 5) × 2]. Results Of the 19 patients evaluable for response, four achieved an objective response, including two complete responses and one partial response among four patients with rhabdomyosarcoma and one additional patient with an undifferentiated sarcoma with rhabdomyoblastic features, and one patient with a fibrosarcoma had stable disease. Among three patients with non-Hodgkin lymphoma, one achieved a partial response and one had stable disease. Diarrhea was the most commonly observed toxicity. Conclusion Irinotecan appears to have promising single-agent activity, particularly against rhabdomyosarcoma, with minimal hematopoietic toxicity, making it ideal for further evaluation in patients at high risk with newly diagnosed disease, particularly in combination with other active agents with nonoverlapping toxicities.

Phase I/Phase II Study of Blinatumomab in Pediatric Patients With Relapsed/Refractory Acute Lymphoblastic Leukemia

Purpose Blinatumomab is a bispecific T-cell engager antibody construct targeting CD19 on B-cell lymphoblasts. We evaluated the safety, pharmacokinetics, recommended dosage, and potential for efficacy of blinatumomab in children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Methods This open-label study enrolled children < 18 years old with relapsed/refractory BCP-ALL in a phase I dosage-escalation part and a phase II part, using 6-week treatment cycles. Primary end points were maximum-tolerated dosage (phase I) and complete remission rate within the first two cycles (phase II). Results We treated 49 patients in phase I and 44 patients in phase II. Four patients had dose-limiting toxicities in cycle 1 (phase I). Three experienced grade 4 cytokine-release syndrome (one attributed to grade 5 cardiac failure); one had fatal respiratory failure. The maximum-tolerated dosage was 15 µg/m2/d. Blinatumomab pharmacokinetics was linear across dosage levels and consistent among age groups. On the basis of the phase I data, the recommended blinatumomab dosage for children with relapsed/refractory ALL was 5 µg/m2/d for the first 7 days, followed by 15 µg/m2/d thereafter. Among the 70 patients who received the recommended dosage, 27 (39%; 95% CI, 27% to 51%) achieved complete remission within the first two cycles, 14 (52%) of whom achieved complete minimal residual disease response. The most frequent grade ≥ 3 adverse events were anemia (36%), thrombocytopenia (21%), and hypokalemia (17%). Three patients (4%) and one patient (1%) had cytokine-release syndrome of grade 3 and 4, respectively. Two patients (3%) interrupted treatment after grade 2 seizures. Conclusion This trial, which to the best of our knowledge was the first such trial in pediatrics, demonstrated antileukemic activity of single-agent blinatumomab with complete minimal residual disease response in children with relapsed/refractory BCP-ALL. Blinatumomab may represent an important new treatment option in this setting, requiring further investigation in curative indications.

High‐dose chemo‐radiotherapy for relapsed or refractory Hodgkin lymphoma and the significance of pre‐transplant functional imaging

We previously reported that three risk factors (RF): initial remission duration <1 year, active B symptoms, and extranodal disease predict outcome in relapsed or refractory Hodgkin lymphoma (HL). Our goal was to improve event‐free survival (EFS) for patients with multiple RF and to determine if response to salvage therapy impacted outcome. We conducted a phase II intent‐to‐treat study of tailored salvage treatment: patients with zero or one RF received standard‐dose ifosfamide, carboplatin, and etoposide (ICE); patients with two RF received augmented ICE; patients with three RF received high‐dose ICE with stem cell support. This was followed by evaluation with both computed tomography and functional imaging (FI); those with chemosensitive disease underwent high‐dose chemoradiotherapy and autologous stem cell transplantation (ASCT). There was no treatment‐related mortality. Compared to historical controls this therapy eliminated the difference in EFS between the three prognostic groups. Pre‐ASCT FI predicted outcome; 4‐year EFS rates was 33% vs. 77% for patients transplanted with positive versus negative FI respectively, P = 0·00004, hazard ratio 4·61. Risk‐adapted augmentation of salvage treatment in patients with HL is feasible and improves EFS in poorer‐risk patients. Our data suggest that normalisation of FI pre‐ASCT predicts outcome, and should be the goal of salvage treatment.

Basis for natural resistance to methotrexate in human acute non-lymphocytic leukemia

The basis of intrinsic resistance of blasts from patients with acute non-lymphocytic leukemia (ANLL) to methotrexate was studied. MTX polyglutamate formation was measured in blast cells from 19 patients with ANLL and in 7 pediatric patients with acute lymphocytic leukemia (ALL), after in vitro incubation for 24 h with 3H-methotrexate. There was no significant differences seen in the total amount of MTX plus polyglutamates measured between ANLL and ALL blasts, indicating that transport defects do not account for intrinsic MTX resistance in ANLL. However, there were significant differences between the amounts of long chain MTX polyglutamates found in ANLL cells as compared to ALL cells. Most, but not all, ANLL blasts were unable to form long chain polyglutamates. In as much as the level of MTX polyglutamates found in blast cells after MTX administration allows for retention of this drug, this property may explain, at least in part, the refractoriness of most patients with ANLL to methotrexate.

Phase II Study of Weekly Gemcitabine and Vinorelbine for Children With Recurrent or Refractory Hodgkin's Disease: A Children's Oncology Group Report

PURPOSE The Childrens Oncology Group conducted this phase II study to assess the efficacy and toxicity of gemcitabine and vinorelbine (GV) in pediatric patients with heavily pretreated relapsed/refractory Hodgkins disease. Both agents have significant single-agent response rates in this setting. METHODS GV was given on days 1 and 8 of each 21-day treatment cycle: vinorelbine 25 mg/m(2)/dose administered via intravenous (IV) push before gemcitabine 1,000 mg/m(2)/dose IV over 100 minutes. Any patients who demonstrated a measurable response (complete response [CR], very good partial response [VGPR], or partial response [PR]) were considered to have experienced a response to GV. Response was evaluated after every two cycles. A two-stage minimax rule was used to test the null hypothesis that the response rate is <or= 40% against an alternative hypothesis of a response rate more than 65%. RESULTS Thirty eligible patients with a median age of 17.7 years (range, 10.7 to 29.4 years) were enrolled. All patients had received at least two prior chemotherapy regimens, and 17 patients had undergone prior autologous stem-cell transplantation. Hematologic toxicity was predominant in all treatment cycles. Nonhematologic grade 3 to 4 toxicity, including elevated hepatic enzymes and hyperbilirubinemia, was less common. Pericardial and pleural effusions developed in one patient after cycles 4 and 5 of GV, consistent with gemcitabine-induced radiation recall. There were no toxic deaths. Measurable responses were seen in 19 (76%) of 25 assessable patients (95% exact binomial CI, 55% to 91%), including six CRs, 11 VGPRs, and two PRs. CONCLUSION GV is an effective and well-tolerated reinduction regimen for children with relapsed or refractory Hodgkins disease.

Phase I and Pharmacokinetic Study of Cetuximab and Irinotecan in Children With Refractory Solid Tumors: A Study of the Pediatric Oncology Experimental Therapeutic Investigators' Consortium

PURPOSE To determine the dose of cetuximab that can be safely combined with irinotecan for treatment of pediatric and adolescent patients with refractory solid tumors. PATIENTS AND METHODS This open-label, phase I study enrolled patients ages 1 to 18 years with advanced refractory solid tumors, including tumors of the CNS. Patient cohorts by age group (children, ages 1 to 12 years; adolescents, ages 13 to 18 years) received escalating weekly doses of cetuximab (75, 150, 250 mg/m(2)) in a 3 + 3 design, plus irinotecan (16 or 20 mg/m(2)/d) for 5 days for 2 consecutive weeks every 21 days. The primary end points were establishing the maximum-tolerated dose (MTD), recommended phase II dose (RPIID), and pharmacokinetics of the combination. Preliminary safety and efficacy data were also collected. RESULTS Twenty-seven children and 19 adolescents received a median of 7.1 and 6.0 weeks of cetuximab therapy, respectively. Cetuximab 250 mg/m(2) weekly plus irinotecan 16 mg/m(2)/d (pediatric) or 20 mg/m(2)/d (adolescent) have been established as the MTD/RPIID. Dose-limiting toxicities included diarrhea and neutropenia. Mild to moderate (grade 1 to 2) acneiform rash occurred in a majority of patients; no grade 3 to 4 rashes were observed. Cetuximab demonstrated dose-dependent clearance in both children and adolescents, similar to that in adults. There were two confirmed partial responses, both in patients with CNS tumors. Stable disease was achieved in 18 patients overall, including 10 patients with CNS tumors (38.5%). CONCLUSION The cetuximab/irinotecan combination can be given safely to children and adolescents with cancer. Promising activity, particularly in CNS tumors, warrants phase II evaluation of this regimen.

Pharmacokinetically Guided Phase 1 Trial of the IGF-1 Receptor Antagonist RG1507 in Children with Recurrent or Refractory Solid Tumors

Purpose: This pediatric phase I study was designed to identify the doses of RG1507, a monoclonal antibody against the Type 1 Insulin-like Growth Factor Receptor (IGF1R), that achieves exposures equivalent to those achieved in adults at recommended doses. Experimental Design: Children with relapsed or refractory solid tumors were treated using the same doses and administration schedules of RG1507 (3 and 9 mg/kg/wk, and 16 mg/kg every 3 weeks [q3W]) as those studied in adults. Detailed pharmacokinetic (PK) sampling was performed after the first dose; selected peak and trough levels were subsequently obtained. Target exposures were ≥85% of mean areas under concentration x time curves (AUCs) in adults at doses of 9 mg/kg/wk and 16 mg/kg q3W. A maximum tolerated dose could be identified if dose-limiting toxicities (DLT) occurred. Results: Thirty-one evaluable patients aged 3–17 years were enrolled at 3 mg/kg/wk (n = 3), 9 mg/kg/wk (n = 18), or 16 mg/kg q3W (n = 10). There were no DLTs. At 9 mg/kg/wk the mean AUC0–7d (21,000 μg h/mL) exceeded the target (16,000 μg h/mL). At 16 mg/kg q3W, the mean AUC021d (70,000 μg h/mL) exceeded the target (59,400 μg h/mL). Clearance normalized to body weight was age dependent. There were no objective responses. Seven patients had stable disease for >12 weeks, including two patients with osteosarcoma with stable disease for 52+ and 78+ weeks. Conclusions: The recommended doses of RG1507 in children with solid tumors are 9 mg/kg/wk and 16 mg/kg q3W. This flexible design is well suited for trials of agents associated with limited toxicity. Clin Cancer Res; 17(3); 611–9. ©2010 AACR.

Allogeneic transplant following brentuximab vedotin in patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma

Abstract Brentuximab vedotin is an antibody drug conjugate that induces durable objective responses in patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma. Fifteen of 160 patients who participated in two pivotal phase 2 studies received a consolidative allogeneic stem cell transplant (allo-SCT) following brentuximab vedotin treatment. This case series describes their experience. The studies were approved by Institutional Review Boards prior to patient enrollment. Patients received 1.8 mg/kg brentuximab vedotin every 3 weeks for up to 16 cycles. The estimated 2-year progression-free survival (PFS) rate was 66%, and the median PFS has not yet been reached. Eleven of the 15 patients were alive and the estimated 2-year survival rate was 80%. The safety of brentuximab vedotin treatment in this series was consistent with the known safety profile in this setting. Brentuximab vedotin is a compelling option for reducing tumor burden to facilitate a consolidative allo-SCT.