Bevacizumab and Irinotecan in Treating Young Patients With Recurrent, Progressive, or Refractory Glioma, Medulloblastoma, Ependymoma, or Low Grade Glioma

Objective response is either a complete response or a partial response observed during the first four courses of treatment and sustained for 8 weeks. The objective response rate will be reported separately for patients with recurrent/progressive malignant glioma(Stratum A), recurrent/progressive instrinsic brain stem tumors(Stratum B), recurrent/progressive medulloblastoma(Stratum C), and recurrent/progressive ependymoma(Stratum D). CR is complete disappearance of all enhancing tumor. PR is >= 50% reduction in tumor size. This outcome measures is not defined for the Stratum E in the protocol.

Disease stabilization is defined as a complete response(CR) or partial response(PR) observed during the first four courses and sustained for 8 weeks; or stable disease (SD) sustained for 6 courses characterized by SD at the end of course 2, at the end of course 4 and at the end of course 6. CR is complete disappearance of all enhancing tumor. PR is >= 50% reduction in tumor size. SD is at least stable and maintenance corticosteroid dose not increased in neurologic examination.

Adverse events are monitored and graded according to the Common Terminology Criteria for Adverse Events. The grade 1 = mild, grade 2=moderate, grade 3 =severe, grade 4=life threatening/disabling, grade 5=death.

Cumulative incidence of sustained objective response provides a percentage of participants experiencing the event of interest at a given follow-up time point (for example, 6-months, 1-year, etc.) in the presence of competing events such as progressive disease or death, and it is estimated using the event data for both the event of interest and the competing events experienced by the study participants. In this sense, it is different than the incidence rates estimated in epidemiological studies in terms of 'incidences per 1000 person years. 6-month Cumulative incidence of sustained objective responses will be reported separately for each stratum.

Progression-Free survival is the interval of time between of protocol treatment and minimum date of documentation of progressive Disease,second malignancy,death due to any cause, or date of last follow-up. Progressive neurologic abnormalities or worsening neurologic status not explained by causes unrelated to tumor progression,OR the appearance of new tumor OR a > 25% increase in the sum of the products of two longest perpendicular diameters of all measurable tumors. K-M method was used to estimate progression-free survival.

Perfusion ratio obtained from magnetic resonance(MR) diffusion imaging may explain changes in the tumor after therapy. Changes in the perfusion ratio will be reported for those strata that have a sufficient number of participants with MR diffusion imaging. The change was calculated from perfusion ratio at Baseline to perfusion ratio at Day 15(values of perfusion ratio at Day 15 - values of perfusion ratio at baseline). The higher of perfusion ratio is worse.

MR perfusion ratio is perfusion solid part of tumor from CBV divided by perfusion frontal while matter. There is no a unit available.

Diffusion ratio obtained from magnetic resonance (MR) diffusion imaging may explain changes in the tumor after therapy. Changes in the diffusion ratio will be reported for those strata that have a sufficient number of participants with MR diffusion imaging. The change was calculated from diffusion ratio at Baseline to diffusion ratio at Day 15 (values of diffusion ratio at Day 15 -values of diffusion ration at baseline). The higher of diffusion ratio is better. MR diffusion ratio is the diffusion solid part of tumor divided by the diffusion frontal white matter. There is no a unit available.

Using Cox proportional hazards models, the association of tumor volume based on FLAIR images with PFS will be investigated for those strata that have a sufficient number of participants with volume FLAIR measurements. Volumetric magnetic resonance imaging is performed to investigate surrogate markers of tumor growth. Volume FLAIR measurements were longitudinal. As we are not comparing the strata, analyses will be done in each stratum separately, and thus we cannot report the Cox model results in the Statistical Analysis section. We consider these estimates 'descriptive' within each stratum. In this analysis, the hazard ratio is a relative measure of likelihood that a study participant experiences the event of interest compared to another participant who has a one-unit lower Log-transformed tumor volume based on FLAIR. The Cox survival model provides the mean hazard ratio along with its 95% confidence interval, which we report below.

Using Cox Proportional hazards Models, the association of Log-transformed tumor enhancing volume with progression-free survival will be investigated. Volumetric magnetic resonance (MR) imaging is performed to investigate surrogate markers of tumor growth. Tumor enhancing volumes were longitudinal. As we are not comparing the strata or study arms, analyses will be done in each stratum separately, and thus we cannot report the Cox model results in the Statistical Analysis section and we consider these estimates 'descriptive' within each stratum. In this analysis, the hazard ratio is a relative measure of likelihood that a study participant experiences the event of interest compared to another participant who has a one-unit lower Log-transformed tumor enhancing volume. The Cox survival model provides the mean hazard ratio along with its 95% confidence interval, which we report below.

Using Cox Proportional Hazards Models, the association of cystic necrosis with progression-free survival will be investigated. Volumetric magnetic resonance (MR) imaging is performed to investigate surrogate markers of tumor growth. Volumes of cystic necrosis were longitudinal. As we are not comparing the strata or study arms, analyses will be done in each stratum separately, and thus we cannot report the Cox model results in the Statistical Analysis section and we consider these estimates 'descriptive' within each stratum. In this analysis, the hazard ratio is a relative measure of likelihood that a study participant experiences the event of interest compared to another participant who has a one-unit lower Log-transformed tumor volume based on cystic necrosis. The Cox survival model provides the mean hazard ratio along with its 95% confidence interval, which we report below.

Using Cox Proportional Hazards Models, the association of tumor diffusion ratios with progression-free survival will be investigated. Magnetic resonance (MR) diffusion imaging is performed to investigate surrogate markers of tumor growth. Tumor diffusion ratios were longitudinal. As we are not comparing the strata or study arms, analyses will be done in each stratum separately, and thus we cannot report the Cox model results in the Statistical Analysis section. And we consider these estimates 'descriptive' within each stratum. In this analysis, the hazard ratio is a relative measure of likelihood that a study participant experiences the event of interest compared to another participant who has a one-unit lower Log-transformed tumor diffusion ratio. The Cox survival model provides the mean hazard ratio along with its 95% confidence interval, which we report below.

Using Cox Proportional Hazards Models, the association of tumor perfusion ratio with progression-free survival will be investigated. Magnetic resonance (MR) perfusion imaging is performed to investigate surrogate markers of tumor growth. Tumor perfusion ratios were longitudinal. As we are not comparing the strata or study arms, analyses will be done in each stratum separately, and thus we cannot report the Cox model results in the Statistical Analysis section. We consider these estimates 'descriptive' within each stratum. In this analysis, the hazard ratio is a relative measure of likelihood that a study participant experiences the event of interest compared to another participant who has a one-unit lower Log-transformed tumor volume perfusion ratio. The Cox survival model provides the mean hazard ratio along with its 95% confidence interval, which we report below.

Blood specimens were collected on the days listed for pharmacokinetic studies for Bevacizumab. These specimens were analyzed to produce steady-state plasma Bevacizumab concentration-time data in study participants. The concentration-time data were analyzed to provide an estimate of the volume of distribution. The data were collected but the analyses of the PK data were conducted by Genentech using a broader cohort of pediatric patients from multiple trials in the paper "Bevacizumab dosing strategy in paediatric cancer patients based on population pharmacokinetic analysis with external validation" published by British Journal of Clinical Pharmacology ,2016 volume 81(1):148-160. The estimates of the volume of distribution were calculated by the model described in the paper.

Blood specimens were collected on the days listed for pharmacokinetic studies for Bevacizumab. These specimens were analyzed to produce steady-state plasma Bevacizumab concentration-time data in study participants. The concentration-time data were analyzed to provide an estimate of the systemic clearance. The data were collected but the analyses of the PK data were conducted by Genentech using a broader cohort of pediatric patients from multiple trials in the paper "Bevacizumab dosing strategy in paediatric cancer patients based on population pharmacokinetic analysis with external validation" published by British Journal of Clinical Pharmacology, 2016 volume 81(1):148-160. The estimates of the systemic clearance were calculated by the model described in the paper.

Blood specimens were collected on the days listed for pharmacokinetic studies for Bevacizumab. These specimens were analyzed to produce steady-state plasma Bevacizumab concentration-time data in study participants. The concentration-time data were analyzed to provide an estimate of the PK parameters. The data were collected but the analyses of the PK data were conducted by Genentech using a broader cohort of pediatric patients from multiple trials in the paper "Bevacizumab dosing strategy in paediatric cancer patients based on population pharmacokinetic analysis with external validation" published by British Journal of Clinical Pharmacology,2016 volume 81(1):148-160. The estimates of the terminal half-life were calculated by the method described in the paper.

The change in VEGF-R2 was calculated from baseline to the time of the 2nd dose (values of 24-48 hours after the 2nd dose at Day 15 - values of pre-dose 1 Day1, i.e., baseline). VEGF-R2 is measured in the relative phosphorylation score which is generated as a ratio of normalized phosphorylated VEGF-R2 versus normalized total VEGF-R2 protein.

The changes in VEGF-R2 are calculated by values at Day 15 minus values at baseline for the patients who had the changes in perfusion from magnetic resonance perfusion imaging. The purpose of reporting descriptive statistics of changes of VEGF-R2 is to provide the information for the correlation coefficients in Section 19.

The change of perfusion in magnetic resonance imaging is calculated by taking the difference between the Day-15 measurements and the Baseline measurements for patients who had the changes of VEGF-R2. The purpose of reporting the descriptive statistics is to provide the information for the correlation coefficients reported in the next section, Section 19. MR perfusion ratio is the ratio of the perfusion measurements in the tumor and the perfusion measurerement in comparative frontal while matter, which is the comparative healthy part of the brain.

Spearman correlation coefficient is used to measure the correlation of the changes in VEGF-R2 with the changes in perfusion ratios. The changes are calculated by values at Day 15 minus values at baseline for VEGF-2 in Section 17 above and perfusion in Section 18 above, respectively. The correlation coefficients are reported in each stratum separately.

The expression of Hypoxia inducible factor-2α, carbonic anhydrase IX (CA9), VEGF-A, and VEGF-R2 will be estimated by immunohistochemistry of paraffin sections in the medulloblastoma,ependymoma and low grade glioma strata. Reported separately for each stratum.

The expression of Hypoxia inducible factor-2α, carbonic anhydrase IX (CA9), VEGF-A, and VEGF-R2 will be estimated by immunohistochemistry of paraffin sections in the medulloblastoma,ependymoma and low grade glioma strata. Reported separately for each stratum.

The expression of Hypoxia inducible factor-2α, carbonic anhydrase IX (CA9), VEGF-A, and VEGF-R2 will be estimated by immunohistochemistry of paraffin sections in the medulloblastoma,ependymoma and low grade glioma strata. Reported separately for each stratum.

The expression of Hypoxia inducible factor-2α, carbonic anhydrase IX (CA9), VEGF-A, and VEGF-R2 will be estimated by immunohistochemistry of paraffin sections in the medulloblastoma,ependymoma and low grade glioma strata. Reported separately for each stratum.

The association of hypoxia inducible factor-2alpha expression with progression-free survival will be investigated for those strata that have a sufficient number of participants with hypoxia inducible factor-2alpha measurements. The hazard ratio was reported for patients who had hypoxia inducible factor-2alpha expression.

The association of CA9 expression with progression-free survival will be investigated for those strata that have a sufficient number of participants with CA9 measurements.

The association of VEGF-A expression with progression-free survival will be investigated for those strata that have a sufficient number of participants with VEGF-A measurements.

The association of VEGF-R2 expression with progression-free survival will be investigated for those strata that have a sufficient number of participants with VEGF-R2 measurements.