Holcombe Grier

Purpose:Mouse models demonstrate a role for RANK and its ligand, RANKL, in osteosarcoma. The primary objective of this single-arm, open-label phase 2 trial was to determine whether denosumab, a RANKL mAb, improved disease control in recurrent osteosarcoma relative to benchmarks derived from historic Children’s Oncology Group clinical trial data.Patients and Methods:Skeletally mature patients ages 11 to 49 years old with measurable disease were eligible for cohort 1, and those with complete surgical resection of all sites of disease were eligible for cohort 2. Patients received denosumab 120 mg subcutaneously every 4 weeks with calcium and vitamin D supplementation. The primary endpoints were RECIST response and remaining event-free for 4 months for cohort 1 and remaining event-free for 12 months for cohort 2. Toxicity, pharmacokinetics, and pharmacodynamic effects were additional endpoints.Results:Fifteen patients in cohort 1 and 38 in cohort 2 were eligible and evaluable for the primary endpoint. One of 15 cohort 1 patients remained event-free at 4 months. There were no objective responses. Ten of 38 cohort 2 patients were event-free at 12 months. The predefined efficacy criteria were not met in either cohort. The most common ≥ grade 3 adverse events were hypocalcemia and hypophosphatemia (8% and 11%, respectively). At steady state, mean serum denosumab trough concentrations were 23.7 to 31 μg/mL in cycles 2 to 7. Serum c-telopeptide and urine n-telopeptide decreased on treatment.Conclusions:Denosumab was well-tolerated with anticipated side effects and pharmacokinetic and pharmacodynamic parameters but had insufficient activity for further development in osteosarcoma.

Supplementary Tables and Figures

Purpose: Mouse models demonstrate a role for RANK and its ligand, RANKL, in osteosarcoma. The primary objective of this single-arm, open-label phase 2 trial was to determine whether denosumab, a RANKL mAb, improved disease control in recurrent osteosarcoma relative to benchmarks derived from historic Children’s Oncology Group clinical trial data. Patients and Methods: Skeletally mature patients ages 11 to 49 years old with measurable disease were eligible for cohort 1, and those with complete surgical resection of all sites of disease were eligible for cohort 2. Patients received denosumab 120 mg subcutaneously every 4 weeks with calcium and vitamin D supplementation. The primary endpoints were RECIST response and remaining event-free for 4 months for cohort 1 and remaining event-free for 12 months for cohort 2. Toxicity, pharmacokinetics, and pharmacodynamic effects were additional endpoints. Results: Fifteen patients in cohort 1 and 38 in cohort 2 were eligible and evaluable for the primary endpoint. One of 15 cohort 1 patients remained event-free at 4 months. There were no objective responses. Ten of 38 cohort 2 patients were event-free at 12 months. The predefined efficacy criteria were not met in either cohort. The most common ≥ grade 3 adverse events were hypocalcemia and hypophosphatemia (8% and 11%, respectively). At steady state, mean serum denosumab trough concentrations were 23.7 to 31 μg/mL in cycles 2 to 7. Serum c-telopeptide and urine n-telopeptide decreased on treatment. Conclusions: Denosumab was well-tolerated with anticipated side effects and pharmacokinetic and pharmacodynamic parameters but had insufficient activity for further development in osteosarcoma.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. Long-term outcomes from Children's Oncology Group study AEWS0031 were assessed to determine whether the survival advantage of interval-compressed chemotherapy (ICC) was maintained over 10 years in patients with localized Ewing sarcoma (ES). AEWS0031 enrolled 568 eligible patients. Patients were randomly assigned to receive vincristine-doxorubicin-cyclophosphamide and ifosfamide-etoposide alternating once every 3 weeks (standard timing chemotherapy [STC]) versus once every 2 weeks (ICC). For this updated report, one patient was excluded because of uncertainty of original diagnosis. The 10-year event-free survival (EFS) was 70% with ICC compared with 61% with STC ( P = .03), and 10-year overall survival (OS) was 76% with ICC compared with 69% with STC ( P = .04). There was no difference in the 10-year cumulative incidence of second malignant neoplasms (SMNs; P_C [see Data Supplement, online only] = .5). A test for interaction demonstrated that ICC provided greater risk reduction for patients with tumor volume ≥200 mL than for patients with tumors <200 mL, but no evidence for a significant interaction in other subgroups defined by age, primary site, and histologic response. With longer-term follow-up, ICC for localized ES is associated with superior EFS and OS without an increased risk for SMN compared with STC. ICC is associated with improved outcomes even in adverse-risk patient groups.

Purpose: Sunitinib is an oral multitargeted receptor tyrosine kinase inhibitor. The purpose of this study was to determine the recommended phase 2 dose, pharmacokinetics, pharmacodynamic effects, and preliminary antitumor activity of sunitinib in a pediatric population. Experimental Design: Patients who were 2 to 21 years of age with refractory solid tumors were eligible if they had measurable or evaluable disease and met baseline organ function requirements. Patients received sunitinib once daily for 28 days followed by a 14-day break between each cycle. Dose levels of 15 and 20 mg/m²/d were evaluated, with dose escalation based on a 3 + 3 design. Sunitinib pharmacokinetics and biomarkers of angiogenesis were also evaluated during the first cycle. Results: Twenty-three patients were treated (median age 13.9 years; range, 3.9–20.6 years). The most common toxicities were neutropenia, thrombocytopenia, elevated liver transaminases, gastrointestinal symptoms, and fatigue. Two patients developed dose-limiting reductions in cardiac ejection fraction prompting a protocol amendment to exclude patients with previous exposure to anthracyclines or cardiac radiation. In patients without these cardiac risk factors, the maximum tolerated dose (MTD) was 15 mg/m²/d. Steady-state plasma concentrations were reached by day 7. No objective responses were observed. Four patients with sarcoma and glioma had stable disease for 2 to 9 cycles. Conclusions: Cardiac toxicity precluded determination of a recommended dose for pediatric patients with previous anthracycline or cardiac radiation exposure. The MTD of sunitinib for patients without risk factors for cardiac toxicity is 15 mg/m²/d for 28 days followed by a 14-day break. Clin Cancer Res; 17(15); 5113–22. ©2011 AACR.