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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/m2) in a 3 + 3 design, plus irinotecan (16 or 20 mg/m2/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/m2 weekly plus irinotecan 16 mg/m2/d (pediatric) or 20 mg/m2/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.

Purpose Tumor growth and metastasis is believed to depend on the tumor's ability to induce neovascularization. Recent studies have indicated that thalidomide inhibits angiogenesis. We performed a phase I and pharmacokinetic study of thalidomide with carboplatin in children with refractory solid tumors. Patients and Methods Carboplatin was administered as a single intravenous dose once every 21 days at a target area under the concentration-time curve of 6 mg/mL·min. Thalidomide was administered daily by mouth. The initial dose level was 100 mg/m2/d with intrapatient dose escalation to a maximum dose of 300 mg/m2/d. The next cohort of patients started at a dose of 300 mg/m2/d, with intrapatient dose escalation to a maximum dose of 500 mg/m2/d. Standard response and adverse event criteria were used. Serial blood samples for thalidomide pharmacokinetics studies were obtained after the first dose. Results Twenty-two patients received 56 cycles of therapy. The maximum tolerated thalidomide dose was 400 mg/m2/d. The dose-limiting toxicity was somnolence. There were no objective responses. Thalidomide's apparent clearance was 55 ± 16 mL/min/m2 and the terminal half-life was 5.9 ± 2.8 hours. There was no evidence of dose-dependent pharmacokinetics in the narrow range studied. Conclusion Thalidomide at a dose of 400 mg/m2/d can be safely administered to children with solid tumors in combination with carboplatin. Somnolence is the major toxicity. In addition, we have characterized the pharmacokinetic behavior of thalidomide in children. This study can serve as the basis for future investigation of thalidomide as an anticancer agent in children.

BACKGROUND An excess risk of second malignancies has been reported in survivors of Ewing's sarcoma. We examined a multiinstitutional data base to reevaluate the risk among survivors of Ewing's sarcoma and to identify possible causal factors. METHODS Information was derived from a data base that included 266 survivors of Ewing's sarcoma. Cumulative incidence rates of second malignancies were calculated. Contributions of clinical features, type and dose of chemotherapy, and cumulative radiation dose to the risk of second malignancies were evaluated. RESULTS After a median follow-up duration of 9.5 years (range, 3.0 to 30), 16 patients have developed second malignancies, which included 10 sarcomas (five osteosarcomas, three fibrosarcomas, and two malignant fibrous histiocytomas) and six other malignancies (acute myeloblastic leukemia, acute lymphoblastic leukemia, meningioma, bronchioalveolar carcinoma, basal cell carcinoma, and carcinoma-in-situ of the cervix). The median latency to the diagnosis of the second malignancy was 7.6 years (range, 3.5 to 25.7). The estimated cumulative incidence rates at 20 years for any second malignancy and for secondary sarcoma were 9.2% (SD = 2.7%) and 6.5% (SD = 2.4%), respectively. The cumulative incidence rate of secondary sarcoma was radiation dose-dependent (P = .002). No secondary sarcomas developed among patients who had received less than 48 Gy, while the absolute risk of secondary sarcoma was 130 cases per 10,000 person-years of observation among patients who had received > or = 60 Gy. CONCLUSION The overall risk of second malignancies after Ewing's sarcomas is similar to that associated with treatment for other childhood cancers. The radiation dose-dependency of secondary sarcomas justifies modification in therapy to reduce radiation doses.

PURPOSE To determine the dose-limiting toxicity and potential efficacy of topotecan in pediatric patients with refractory malignant solid tumors. PATIENTS AND METHODS In this phase I clinical trial, 27 patients received topotecan 0.75-1.9 mg/m2 by continuous intravenous infusion daily for 3 days. Fifty-three treatment courses were given to these patients. RESULTS Myelosuppression was the dose-limiting toxicity at levels of 1.3 to 1.9 mg/m2 for 3 days, requiring significant support with transfused packed RBCs and platelets. Myelosuppression was variable in severity at the 1.0-mg/m2 dosage level; thus, additional patients were treated with this dosage, followed by human recombinant granulocyte-colony stimulating factor (G-CSF). Other toxicities were not significant. One patient with neuroblastoma had a complete response that lasted for 8 months. Stable disease activity was recorded for other patients with neuroblastoma, rhabdomyosarcoma, and islet cell carcinoma. Pharmacokinetic studies showed that topotecan plasma concentrations ranged from 1.6 to 7.5 ng/mL during infusions of 1.0 mg/m2/d, and that there was a biphasic plasma distribution with a mean terminal half-life of 2.9 +2- 1.0 hours. CONCLUSION Topotecan is a promising anticancer agent that deserves phase II testing in pediatric solid tumors. We recommend that pediatric phase II topotecan trials use 1.0 mg/m2/d for 3 days as a constant intravenous infusion, followed by G-CSF for 14 days, and that these treatment courses be repeated every 21 days.

PURPOSE The prognostic value of tumor-cell DNA content (ploidy) was evaluated in children with unresectable, nonmetastic rhabdomyosarcoma of embryonal histology. PATIENTS AND METHODS Flow-cytometric techniques were used to estimate the ploidy of tumor specimens from 34 patients with embryonal rhabdomyosarcoma who were enrolled in the intergroup rhabdomyosarcoma study III (IRS III) from 1985 to 1991. Tumors were classified as diploid or hyperdiploid (DNA content, 1.1 to 1.8 times that of normal diploid cells). The influence of ploidy on clinical outcome was assessed by the Kaplan-Meier technique and Cox regression analysis with stepwise selection. RESULTS Twelve of the tumor specimens were diploid and 22 were hyperdiploid. The patient groups defined by diploid or hyperdiploid tumors had similar presenting characteristics (eg, age, tumor size, and anatomic site). Significantly more children with hyperdiploid tumors achieved a complete response than did children with diploid tumors (85% v 42%; P = .01). The probability of progression-free survival at 5 years (+/- SE) was 91% +/- 6% for the hyperdiploid group, compared with 17% +/- 11% for the diploid group (P < .001). Hyperdiploidy was also associated with a significantly higher overall survival rate at 5 years: 96% +/- 4% versus 50% +/- 14% (P = .004). Ploidy retained its prognostic significance after adjustment for tumor site in the Cox regression model. CONCLUSION Tumor-cell ploidy strongly correlates with outcome in children with nonmetastic, unresectable embryonal rhabdomyosarcoma. The two biologically distinct groups identified by this measure would benefit from further refinements in risk-directed therapy.

PURPOSE Evaluation of high-dose chemotherapy with autologous bone marrow rescue (ABMR) in pediatric malignant gliomas. PATIENTS AND METHODS Newly diagnosed (n = 11) and recurrent (n = 2) malignant glioma patients received high-dose chemotherapy within 4 weeks of surgery; three had near total and 10 had subtotal resection/biopsy. High-dose thiotepa (300 mg/m2) and cyclophosphamide (2 g/m2) daily for 3 days were followed by ABMR; response was evaluated at day 30. At day 60, patients with at least stable disease received hyperfractionated (n = 9) or conventional external-beam radiotherapy (n = 2) preceded by local radioactive iodine 125 implantation (n = 2) or radiosurgery (n = 1). RESULTS Grade III and IV toxicities after ABMR consisted of mucositis (n = 12), cardiomyopathy (n = 1), acute abdomen (n = 1), pneumonitis (n = 2), and infection (n = 2). One complete and three partial responses were observed; the objective response rate was 31% (95% confidence interval, 9% to 61%). Seven had stable disease, one had disease progression, and one died of toxicity before response evaluation. The median overall and progression-free survival durations after combined modality therapy were 14 months (range, 4 to 30+) and 9 months (range, 0 to 30+), respectively. One patient remains progression-free at 30+ months. Radionecrosis and white matter changes occurred in three patients: one after hyperfractionated irradiation, and two after 125I implants. CONCLUSION For patients with bulky residual disease after surgery, survival with this aggressive chemotherapy and radiation regimen is not better than that reported for conventional treatment regimens.

9547 Background: Irinotecan has shown antitumor activity in a number of pediatric tumors. In adults with colorectal cancer, combining irinotecan with cetuximab enhances clinical activity as compared to treatment with irinotecan alone. We implemented this first-in- pediatrics phase I study to determine the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) of cetuximab and irinotecan in pediatric patients. Methods: 35 heavily pre-treated pts with refractory solid tumors were enrolled: brainstem glioma/astrocytoma (16), hepatoblastoma (4), neuroblastoma (2), other (13). Weekly cetuximab was escalated in 3 sequential dose levels: 75, 150 or 250mg/m2; Irinotecan was given at 16 or 20 mg/m2/day over 1 hour [daily × 5] for two weeks, every 21 days. Correlative EGFR expression (immunohistochemistry and FISH) and/or mutations, pharmacokinetics (PK) of and immune response to cetuximab were performed. Results: Pts were treated in two age cohorts (ages 1–12 yrs = Group A, and 13–18 yrs = Group B). PK analyses show linearity, with similar t1/2, clearance, and volume of distribution between groups. Irinotecan-related DLT in 2/6 pts in Group A/dose 2 necessitated dose de-escalation. Three pts experienced Grade 3 hypersensitivity infusion reaction and were discontinued. A pt with an EGFR-negative high-grade glioma (dose level 1) achieved a >70% reduction in tumor size and remains on study for 16+ months (24 cycles). A pt with ependymoma experienced a partial response (PR) and continues on cycle 12+. 9 pts received ≥4 cycles of therapy. 16 pts had a best response of stable disease or PR (mean 17 wks, range 5–66+ wks) for a clinical benefit rate of 45%. Conclusions: The combination of cetuximab and irinotecan is well-tolerated over multiple repeat cycles without cumulative toxicity in children with refractory CNS and non-CNS solid tumors. Promising preliminary anti-cancer activity was observed in a variety of pediatric solid tumors. Detailed biologic correlative and PK data will be presented. [Table: see text] No significant financial relationships to disclose.

9548 Background: Platinums have significant activity in a wide variety of pediatric tumors, and oxaliplatin exhibits synergy with 5FU and LV in adults with colorectal cancer in FOLFOX regimens. The primary objectives of this study are to determine the maximum tolerated dose (MTD) of the modified FOLFOX6 regimen in pediatric tumors. Secondary objectives include safety, PK pharmacokinetic (PK) and PET scan efficacy analyses. Methods: Pts age 2 and LV 400 mg/m2 over 2 hours on day 1 followed by a 5FU bolus of 400 mg/m2 then 2,400 mg/m2 continuous infusion over 46 hours, every 2 weeks (3 courses = 1 cycle), with integrated PK sampling in a limited dose escalation design. Standard 3+3 dose escalation, definitions of dose limiting toxicity (DLT), and dose modification for toxicity are implemented. The MTD is expanded to 15 patients to confirm and further characterize tolerability and toxicity. Results: To date, 15 very heavily pre-treated patients (7 M, 8 F) have received 25 cycles (range 1–4, median 2) of treatment at 2 dose levels. One of 8 pts at dose level 2 (oxaliplatin 100 mg/m2) developed DLT (delay in repeat treatment > 14 days due to grade 3 platelets). Treatment has been well tolerated. The most frequently reported related grade 3–4 adverse events (AEs) are reversible leukocytes (29%), neutropenia (43%), platelets (35%) and lymphopenia (21%). 31 of 90 courses (34%) have been delayed for neutropenia and thrombocytopenia. Anti-tumor activity to date includes a confirmed partial response lasting 15 weeks in a patient with osteosarcoma, and prolonged stable disease in 5 other pts with brain tumors (2), hepatoblastoma (2) and sarcoma (1). Conclusions: The modified FOLFOX6 regimen has significant but reversible myelosuppression in heavily pre-treated pediatric patients, but is tolerable and has promising activity in several tumor types. Cohort expansion continues at 100 mg/m2 of oxaliplatin. PET scan and pharmacokinetic analyses will be presented. No significant financial relationships to disclose.

8521 Background: Vinca alkaloids have broad activity against pediatric malignancies. Vinorelbine is a unique semi synthetic vinca alkaloid that has less potential of neurotoxicity. These observatio...

The legend for Fig 1 in the report entitled "Tumor-Cell DNA Content Predicts Outcome in Children and Adolescents With Clinical Group III Embryonal Rhabdomyosarcoma" by Pappo et al (J Clin Oncol 11:1901–1905, 1993) incorrectly identified parts A and B. The legend is reprinted here correctly in its entirety with the figure. Please see the PDF for Figure.