The primary objective of this study was to evaluate the safety and pharmacokinetics of up to 3 different dose schedules of panitumumab in pediatric patients with solid tumors.
This is an open-label, multi-center, single arm, dose-ranging, clinical study. Panitumumab will be administered by intravenous infusion to 4-6 patients per cohort. Three planned cohorts, stratified by age, will be studied at 100% of the recommended panitumumab dose for each treatment schedule as defined in adults. Enrollment will start with a 2.5 mg/kg once weekly administration to the 12 to \< 18 year old patients. Upon demonstration of sufficient safety additional cohorts will open; a 2.5 mg/kg once weekly administration to the 1 to \< 12 year old patients and a 6.0 mg/kg once every two weeks to the 12 to \< 18 year old patients. The decision to advance to the next cohort will be based on observance of ≤ 33% incidence of a dose limiting toxicity during the evaluation period. Subsequent cohorts of 6.0 mg/kg once every two weeks to the 1 to \< 12 year old patients and 9.0 mg/kg once every three weeks to both age groups will open once sufficient safety in each cohort is determined. Participants may stay on study treatment until disease progression.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
31
Panitumumab administered by intravenous infusion
Research Site
Los Angeles, California, United States
Research Site
San Francisco, California, United States
Research Site
Washington D.C., District of Columbia, United States
Number of Participants With Dose-limiting Toxicities (DLTs)
Any panitumumab related grade 3 or 4 hematologic or non-hematologic toxicity (graded according to the modified Common Terminology Criteria for Adverse Events (CTCAE) version 3.0 criteria) was considered a DLT with the exception of alopecia and fatigue. Hypomagnesemia, nausea, diarrhea, vomiting, and skin or nail toxicities constituted a DLT only of the following occured: • Grade 3 or 4 hypomagnesemia that persisted for at least 5 days despite maximal magnesium replacement; • Grade 3 or 4 diarrhea, nausea, or vomiting that persisted for at least 5 days despite maximum supportive therapy; • Grade 4 skin or nail toxicity.
Time frame: 28 days from initial administration of panitumumab for the 2.5 and 6 mg/kg cohorts and 21 days from first administration for the 9 mg/kg cohort.
Number of Participants With Adverse Events (AEs)
A serious adverse event is defined as an AE that: • is fatal; • is life threatening; • requires in-patient hospitalization or prolongation of existing hospitalization; • results in persistent or significant disability/incapacity; • is a congenital anomaly/birth defect; • other significant medical hazard. The investigator assessed whether adverse events were related to panitumumab. The severity of adverse events was based on CTCAE version 3 (with the exception of skin- or nail-related toxicities which were graded using the CTCAE version 3.0 with modifications), according to the following: Grade 1 = Mild (aware of sign or symptom, but easily tolerated); Grade 2 = Moderate (discomfort enough to cause interference with usual activity); Grade 3 = Severe (incapacitating with inability to work or do usual activity); Grade 4 = Life-threatening or disabling; Grade 5 = Fatal.
Time frame: From first dose date to end of study date. The median duration of study was 47 days.
Maximum Observed Concentration (Cmax) of Panitumumab
Panitumumab serum concentration was measured using an enzyme-linked immunosorbent assay (ELISA). The lower limit of quantification (LLOQ) of the assay was 400 pg/mL. Concentrations below the LLOQ were set to zero.
Time frame: First dose (Day 1) and third dose (Day 15/29/43 for the QW, Q2W and Q3W cohorts respectively). Samples were collected over the dosing interval for each treatment cohort (7, 14 or 21 days for QW, Q2W and Q3W cohorts respectively).
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Research Site
Chicago, Illinois, United States
Research Site
Minneapolis, Minnesota, United States
Research Site
Kansas City, Missouri, United States
Research Site
New York, New York, United States
Research Site
Cleveland, Ohio, United States
Research Site
Portland, Oregon, United States
Research Site
Nashville, Tennessee, United States
...and 1 more locations
Minimum Observed Concentration (Cmin) of Panitumumab
Time frame: First dose (Day 1) and third dose (Day 15/29/43 for the QW, Q2W and Q3W cohorts respectively). Samples were collected over the dosing interval for each treatment cohort (7, 14 or 21 days for QW, Q2W and Q3W cohorts respectively).
Area Under the Concentration-time Curve During the Dosing Interval (AUC0-tau) for Panitumumab
The area under the serum concentration-time curve from time zero to the end of the dosing interval (AUCtau), estimated using the linear trapezoidal method.
Time frame: First dose (Day 1) and third dose (Day 15/29/43 for the QW, Q2W and Q3W cohorts respectively). Samples were collected over the dosing interval for each treatment cohort (7, 14 or 21 days for QW, Q2W and Q3W cohorts respectively).
Half-life (t1/2) for the Terminal Phase (First Dose) or Dosing Interval (Third Dose) of Panitumumab
Time frame: First dose (Day 1) and third dose (Day 15/29/43 for the QW, Q2W and Q3W cohorts respectively). Samples were collected over the dosing interval for each treatment cohort (7, 14 or 21 days for QW, Q2W and Q3W cohorts respectively).
Serum Clearance (CL) of Panitumumab
Time frame: First dose (Day 1) and third dose (Day 15/29/43 for the QW, Q2W and Q3W cohorts respectively). Samples were collected over the dosing interval for each treatment cohort (7, 14 or 21 days for QW, Q2W and Q3W cohorts respectively).
Number of Participants Who Developed Antibodies to Panitumumab
Three validated assays were used to detect the presence of anti-panitumumab antibodies. Two screening immunoassays, an acid-dissociation enzyme-linked immunosorbent assay (ELISA) and a Biacore-based biosensor assay, were used to detect antibodies capable of binding to panitumumab. All samples confirmed to be positive by drug specificity in either screening immunoassay were further tested for neutralizing antibodies in a cell-based epidermal growth factor receptor (EGFR) phosphorylation bioassay. The number of participants who developed antibodies to panitumumab is the number of participants with a non-positive (including missing) antibody result at baseline and a positive antibody result at any post-baseline time point.
Time frame: Before panitumumab administration on Day 1, Day 43, Day 169 and 30 days after last dose for all cohorts.
Percentage of Participants With an Objective Response
Disease assessments were based on investigator review of scans using modified Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 criteria. A participant was considered a responder if their best response was either a complete or partial response. Participants without a post-baseline assessment were considered non-responders. A complete or partial response was confirmed no less than 4-weeks after the criteria for response were first met. Complete Response (CR): Disappearance of all target and non-target lesions, normalization of tumor markers and no new lesions. Partial Response (PR): At least a 30% decrease in the size of target lesions, no progression of non-target lesions and no new lesions, or, the disappearance of all target lesions, persistence of one or more non-target lesion(s) not qualifying for either CR or progressive disease (PD) or/and maintenance of tumor marker level above normal limits, and no new lesions.
Time frame: Tumor response was assessed every 8 weeks through week 48 and every 3 months thereafter until disease progression or end of study. The data cut-off for the analysis was 17 June 2015; median duration of study was 47 days.
Percentage of Participants With Disease Control
Disease assessments were based on investigator review of scans using modified RECIST version 1.0 criteria. A participant was considered to have disease control if their best response is either a complete or partial response, or stable disease. Participants without a post-baseline assessment were considered to not have disease control. A complete or partial response was confirmed no less than 4-weeks after the criteria for response were first met. A best overall response of SD requires a visit response of SD or better, no earlier than 49 days after the date of enrollment. Stable disease (SD): Neither sufficient shrinkage of target lesions to qualify for a PR nor sufficient increase to qualify for PD and no progression of existing non-target lesions and no new lesions.
Time frame: Tumor response was assessed every 8 weeks through week 48 and every 3 months thereafter until disease progression or end of study. The data cut-off for the analysis was 17 June 2015; median duration of study was 47 days.