Background:
Pediatric solid tumors represent approximately one fourth of cancer diagnoses in children. Despite intensive regimens, patients with metastatic or recurrent tumors have unsatisfactory survival rates. Therefore new therapies are needed to improve outcomes.
Members of the TNF ligand superfamily induce death in tumor cells through direct ligation of death receptors and apoptosis induction.
TRAIL (TNF-related apoptosis inducing ligand) has specific anti-tumor activity against a wide range of tumor cells without inducing death in normal cells. TRAIL-induced apoptosis has been demonstrated in a wide variety of pediatric solid tumors, including Ewing's sarcoma, osteosarcoma, neuroblastoma, and rhabdomyosarcoma.
HGS-ETR2 (Human Genome Sciences; human monoclonal antibody) is a fully human monoclonal antibody that agonistically binds TRAIL receptor 2 and, like TRAIL itself, induces apoptosis in a variety of malignant cell types with little effect on normal cells.
Limited caspase 8 expression is a primary factor in limiting to TRAIL mediated cell death in some tumors; interferon gamma has been shown to be effective in increasing caspase-8 expression in tumors and in restoring sensitivity of tumors to TRAIL mediated cell death.
Objectives:
To determine the tolerance of the adult maximum tolerated dose and dose limiting toxicities of lexatumumab in patients with refractory pediatric solid tumors.
To determine the MTD of lexatumumab in the presence of fixed dosing of interferon gamma 1b at 25 mcg/m(2) SC three times/week, which is less than the FDA approved dose.
To assess the pharmacokinetics of lexatumumab or lexatumumab in combination with interferon gamma 1b in patients with pediatric malignant tumors refractory to standard therapy.
Eligibility:
Patients must be 1-30 years of age with solid malignant tumors refractory to standard therapy.
Design:
A Phase I dose escalation study with 4 planned dose levels of lexatumumab starting at 30% of the adult MTD and escalating up to 100% of the adult MTD, followed by a second dose escalation using five lexatumumab dose levels in patients concomitantly receiving interferon gamma 1b.
Three (expanded to six if DLT occurs) patients will be enrolled at each dose level of lexatumumab until the adult MTD is reached and 6 patients will be enrolled at the adult MTD dose. The MTD cohort of lexatumumab alone and combined regimen will be expanded to include 12 patients, which should include a minimum of 6 patients less than or equal to 12 years of age. Once 6 patients greater than 12 years of age have completed lexatumumab alone, new patients greater than 12 years of age will be enrolled in the combined regimen. Similarly, once 6 patients complete lexatumumab alone who are less than or equal to 12 years of age, new patients less than or equal to 12 years of age will be enrolled in the combined regimen. A final dose escalation of interferon gamma 1b will be performed with the maximum dose level of lexatumumab, to a dose level wherein archival tissue demonstrated upregulation of caspase 8.