Phase 1 trial of temsirolimus in combination with irinotecan and temozolomide in children, adolescents and young adults with relapsed or refractory solid tumors: a Children's Oncology Group Study

BACKGROUND

mTOR inhibitors have activity in pediatric tumor models. A phase I trial of the mTOR inhibitor temsirolimus (TEM) with irinotecan (IRN) and temozolomide (TMZ) was conducted in children with recurrent/refractory solid tumors, including central nervous system (CNS) tumors.

METHODS

Escalating doses of intravenous (IV) TEM were administered on days 1 and 8 of 21-day cycles. IRN (50 mg/m(2)/dose escalated to a maximum of 90 mg/m(2)/dose) and TMZ (100 mg/m(2)/dose escalated to a maximum of 150 mg/m(2)/dose) were administered orally (PO) on days 1-5. When maximum tolerated doses (MTD) were identified, TEM frequency was increased to weekly.

RESULTS

Seventy-one eligible pts (median age 10.9 years, range 1.0-21.5) with neuroblastoma (16), osteosarcoma (7), Ewing sarcoma (7), rhabdomyosarcoma (4), CNS (22) or other (15) tumors were enrolled. Dose-limiting hyperlipidemia occurred in two patients receiving oral corticosteroids. The protocol was subsequently amended to preclude chronic steroid use. The MTD was identified as TEM 35 mg/m(2) IV weekly, with IRN 90 mg/m(2) and TMZ 125 mg/m(2) PO on days 1-5. At higher dose levels, elevated serum alanine aminotransferase and triglycerides, anorexia, and thrombocytopenia were dose limiting. Additional ≥ grade 3 regimen-related toxicities included leukopenia, neutropenia, lymphopenia, anemia, and nausea/vomiting. Six patients had objective responses confirmed by central review; three of these had sustained responses through ≥ 14 cycles of therapy.

CONCLUSION

The combination of TEM (35 mg/m(2)/dose IV weekly), IRN (90 mg/m(2)/dose days 1-5) and TMZ (125 mg/m(2)/dose days 1-5) administered PO every 21 days is well tolerated in children. Phase 2 trials of this combination are ongoing.

Incidence of febrile neutropenia (FN) with pegfilgrastim (PF) on day of chemotherapy (D1) versus 24–72 hrs later (D2)

e20664

Background: Docetaxel, doxorubicin hydrochloride, and cyclophosphamide (TAC) is a commonly used adjuvant chemotherapy (C) regimen in patients (pts) with high risk breast cancer (BC). Pegfilgrastim (PF) is a long acting G-CSF known to decrease the risk of FN. It is typically given the day after C. Illinois CancerCare (ILCC) is a large oncology practice that provides cancer care to many communities in Illinois. For patients with limited access to medical care, in past PF has been given on same day as C. In this study we have compared the incidence of FN in pts who received PF on the same day as TAC (D1) versus those who received it 24–72 hrs after C (D2). Methods: All pts treated for BC at ILCC between 09/2004 and 08/2008, and received TAC and PF were deemed eligible. Logistic regression was used to analyze the association between incidence of FN and type of regimens. Results: Of the 56 eligible pts (55 females), mean age 52.9 yrs (range 27.8–84.8 yrs), 43 patients received PF on D1 and 13 pts received PF on D2. 7 of 43 pts that received PF on D1 developed FN as compared to 1 of 13 pts that received PF on D2. There was a 2.1 times greater probability of developing FN in pts that received PF on D1 versus the pts who received it on D2; 95% CI (0.28–15.6). We did not observe a statistical significance for the above association in univariate analyses or after adjusting for age, stage of disease and receptor status (p>0.05). The lack of significance could be due to small patient population. Conclusions: The odds of developing FN in patients who received PF on the same day as TAC was 2.1 as compared to pts who received it on D2, this difference was statistically not significant.

[Table: see text]

Phase I and pharmacokinetic (PK) study of lenalidomide (LEN) in pediatric patients with relapsed/refractory solid tumors or myelodysplastic syndrome (MDS): A Children's Oncology Group Phase I Consortium study

10023

Background: LEN, which has immunomodulatory, antiangiogenic, and antiproliferative effects, is indicated for the treatment of adults with MDS and multiple myeloma. We report the final results of a phase 1 and PK study of LEN in children with recurrent or refractory solid tumors (ST) or MDS. Methods: LEN was administered by mouth once daily for 21 of 28 days. Cohorts of 3 to 12 children with ST were enrolled at 15, 25, 40, 55 and 70 mg/m2/d dose levels. Children with MDS received a fixed dose of 5 mg/m2/d. PK and correlative biology studies were performed in cycle 1. Results: 49 patients (23 female), median age 16 years (range, 1–21) were enrolled and received a median of 1 cycle (range 1–11). 39/46 ST patients and 3/3 MDS patients were fully evaluable for toxicity. 0/3 patients with MDS had DLT. At 15 mg/m2/d, 1/6 ST patients developed DLT (Gr 3 hypercalcemia). At 25 mg/m2/d 1 patient had a cerebrovascular ischemic event of uncertain relationship to LEN; future subjects were screened for thromboembolic risk factors prior to enrollment. At 40 mg/m2/d 3/12 patients developed DLTs (Gr 3 hypophosphatemia/hypokalemia; Gr 4 neutropenia delaying the start of the next cycle for > 7 days; Gr 3 somnolence); at 55 mg/m2/d 1/6 patients developed DLT (Gr 3 urticaria). At 70 mg/m2/d 0/6 patients had DLT. No further dose escalation was attempted. No objective responses were observed. LEN enhanced IL-2 and IL-15 concentrations; NK expansion and activation; and NK and LAK cytotoxicity (Ayello, ASH, 2008). The median apparent LEN clearance and half-life were 135 ± 45 ml/min/m2 and 2.3 ± 1.1 hr. Conclusions: LEN is well tolerated at doses up to 70 mg/m2/d x 21d of 28 days in children with recurrent or refractory ST. Enhancement of immune function is significant. PK parameters in children are similar to those in adults.

No significant financial relationships to disclose.

A phase I trial and pharmacokinetic study of IMC-A12 in pediatric patients with relapsed/refractory solid tumors: A Children's Oncology Group Phase I Consortium study

10013

Background: IMC-A12, a fully human IgG1 monoclonal antibody to the Insulin-Like Growth Factor-I Receptor (IGF-IR), is active preclinically in a variety of pediatric solid tumors. We performed a phase I trial to determine the toxicities, maximum tolerated dose (MTD), pharmacokinetics (PK), and pharmacodynamics (PD) of IMC-A12 in children with refractory solid tumors. Methods: IMC-A12 was administered as a weekly 1 hr IV infusion, without interruption. Two dose levels, 6 and 9 mg/kg, were evaluated using a standard 3+3 cohort design. After defining initial safety, patients (pts) with refractory Ewing sarcoma (ES) were treated in an expanded cohort at each dose level. Results: 24 eligible patients (11 male), median 15.3 yrs (range, 7.0 to 21.5), were enrolled. Among the 12 pts enrolled on the dose-escalation component, DLT (grade 4 thrombocytopenia) occurred in 1/6 pts at 6 mg/kg. No DLTs occurred in 6 pts at 9 mg/kg or in the ES cohort. 1/10 evaluable pts with ES at the 6 mg/kg dose had a partial response; no CRs were observed. Grade 2 or higher non-DLTs possibly attributable to IMC-A12 observed in the first course include anemia (n=4), leukopenia (n=1), lymphopenia (n=2), neutropenia (n=2), opportunistic infection (n=1), ↑liver transaminases (n=2), and hyperglycemia (n=1). No ≥ grade 3 hyperglycemia occurred. Mean (± SD) trough IMC-A12 concentrations were 59.8 ± 31.1 and 117 ± 70.8 μg/ml at the 6 and 9 mg/kg dose levels, respectively. A majority of pts at both dose levels exhibited > 50% reduction in PBMC IGF-IR protein levels. Conclusions: In order to exceed target trough concentrations associated with optimal anti-tumor activity in pre-clinical models, 9 mg/kg IV weekly is the recommended Phase II IMC-A12 dose in children. A phase II protocol for children with refractory solid tumors will be performed.

[Table: see text]

Phase I trial and pharmacokinetic study of two schedules of vincristine, oral irinotecan, and temozolomide (VOIT) for children with refractory solid tumors: A Children's Oncology Group Phase I Consortium study

10017

Background: In preclinical models, temozolomide (TMZ) and vincristine (VCR) are synergistic with irinotecan (IRN). We sought to determine the dose limiting toxicities (DLTs) and maximum tolerated dose (MTD) of orally administered IRN given on two different schedules together with TMZ and VCR in children with refractory solid tumors, using cefixime to reduce IRN-associated diarrhea. Methods: Schedule A: Oral IRN daily for 5 days for 2 weeks (dx5x2), with VCR 1.5 mg/m2 on days 1 and 8 and TMZ 100 mg/m2 on days 1 - 5. Schedule B: Oral IRN daily for 5 days for 1 week (dx5x1) with VCR 1.5 mg/m2 on day 1 and TMZ 100 - 150 mg/m2 on days 1 - 5. Courses were repeated every 3 weeks. A standard cohorts of 3 + 3 design was used. Results: On Schedule A, 18 evaluable patients (median age 15 yrs, range 3 - 21) received 55 courses. At IRN 50 mg/m2/day, 4/12 pts had DLT (hepatotoxicity, abdominal pain, anorexia, hypokalemia, and thrombocytopenia). The oral IRN MTD on this dx5x2 schedule was 35 mg/m2/d (1/6 pts with DLT of hypoalbuminemia). On Schedule B, 18 evaluable patients (median age 9 yrs, range 3–21) received 71 courses of oral IRN 70 - 90 mg/m2/d x 5 with TMZ 100 - 150 mg/m2/d x 5. At oral IRN 90 mg/m2/d with TMZ 150 mg/m2/d, 0/6 pts had DLT, and no Grade 4 toxicities were seen. No further doses were explored. First-course and cumulative toxicity appeared worse with Schedule A, including 3 patients with responding or stable tumors who withdrew due to fatigue, nausea, and weight loss. UGT1A1*28genotype did not correlate with DLT. At the oral IRN MTD of 90 mg/m2/d, the median SN-38 AUCinf was 72 ng/ml*h. One patient with osteosarcoma had a confirmed partial response. Unconfirmed complete and partial responses were seen in 2 Ewing sarcoma patients. Eight additional patients received > 6 courses, including 2 each with neuroblastoma and medulloblastoma. Conclusions: The dx5x1 schedule of VOIT was well tolerated, with SN-38 exposures similar to those achieved with intravenous IRN. Activity on this and prior studies suggests a potential role for VOIT in sarcoma patients.

No significant financial relationships to disclose.

Phase I study of sorafenib in children with refractory solid tumors: A Children's Oncology Group Phase I Consortium trial

10012

Background: Sorafenib, an oral multitargeted kinase inhibitor, is indicated for treatment of adults with refractory renal cell or hepatocelluar carcinoma. We performed a phase I trial to determine the toxicities, maximum tolerated dose (MTD), pharmacokinetics (PK), and pharmacodynamics (PD) of sorafenib in children with refractory solid tumors. Methods: Sorafenib was administered q12h for 28 consecutive day cycles. Cohorts of 3–12 patients were enrolled at 105, 130, 150, 200, and 250 mg/m2/dose dose levels. Results: 34 eligible pts [16M, median age 14.6 yrs, (range, 5–21)] with osteosarcoma (n = 8), rhabdomyosarcoma (n = 3), other sarcomas (n = 13), hepatoblastoma (n = 3), or other solid tumors (n = 7) received 1–22 cycles (median 2). Grade 3 dose-limiting toxicity (DLT) occurred in 4/6 pts at the starting dose (150 mg/m2) and included hypertension (n = 1), rash/urticaria (n = 1), back pain (n = 1), thrombocytopenia (n = 1) and ALT/AST (n = 1). No DLTs were observed at 105 (n = 6) or 130 (n = 3) mg/m2, and the dose was re-escalated to 150 mg/m2 with modified eligibility criteria (normal ALT) and revised guidelines for grading and management of hypertension. Gr 3 DLTs occurred in 1/6 pts (lipase) at 150 mg/m2 and 2/2 pts (hyponatremia, hand-foot syndrome) at 250 mg/m2. At 200 mg/m2 only 1/6 pts experienced DLT (gr 3 ALT). No objective responses were observed, but 2 pts had tumor shrinkage. Sorafenib AUC did not increase proportionally with dose - the mean AUC0–24h was similar at 150 mg/m2 (28±24 μg · h/mL, n = 9) and 200 mg/m2 (28±17 μg · h/mL, n = 4). Tmax was prolonged and variable (10±11 h, n = 19). Plasma VEGFR (n = 13) decreased from 9.9±1.6 ng/mL at baseline to 8.3±1.7 ng/mL by d 28 (p < 0.001). Conclusions: The MTD of sorafenib in children with solid tumors is 200 mg/m2, similar to the adult recommended dose (400 mg).

No significant financial relationships to disclose.

Phase I study of oral irinotecan, temozolomide, and vincristine for children with refractory solid tumors: A Children's Oncology Group study

9563

Background: Both temozolomide (TEM) and vincristine (VCR) can increase the preclinical activity of low-dose protracted irinotecan (IRN) against pediatric solid tumors. Because these drugs have different dose-limiting toxicities (DLTs) and mechanisms of action, we combined these three agents and sought to determine the maximum tolerated dose (MTD) of orally administered IRN when given with fixed- dose TEM and VCR in children with relapsed or refractory solid tumors, using the antibiotic cefixime to reduce IRN-associated diarrhea. Methods: We studied two dose levels of oral IRN (35 or 50 mg/m2) administered on days 1–5 and 8–12, combined with oral TEM 100 mg/m2 on days 1–5 and intravenous VCR 1.5 mg/m2 on days 1 and 8. Courses were repeated every 21 days. Oral cefixime was started 5 days before chemotherapy and continued daily. Results: Of 21 patients enrolled, 17 (ages 3–21, median 14 yrs) were evaluable for toxicity and have to date received 46 courses (range 1–8, median 2). At the IRN dose of 50 mg/m2/d, 4 of 12 patients had DLT, including elevated ALT/AST (1), abdominal pain (1), hypokalemia (1), anorexia (1), thrombocytopenia (1), and fatal liver failure in a patient with metastatic disease in the liver and porta hepatis (1). In contrast, none of 5 patients treated at the dose of 35 mg/m2/d experienced first-course DLT, defining this dose as the MTD. UGT1A1 genotype did not correlate with DLT in this small trial. The median SN-38 lactone area under the curve (0–6h) at the IRN dose of 50 mg/m2/day was 13.5 ng/ml*h (range 3.8 to 30.9); pharmacokinetic analysis of patients treated at 35 mg/m2/day is ongoing. Six patients with the following tumors received more than 2 courses: neuroblastoma, ependymoma, hepatoblastoma, fibrillary astrocytoma, osteosarcoma, and Ewing sarcoma. Central review of response data is underway. Three patients continue on therapy at the MTD. Conclusions: Oral administration of IRN together with TEM and VCR was feasible and well tolerated at the MTD of 35 mg/m2 given dx5x2. Further study using a shorter 5-day course of oral IRN is planned.

No significant financial relationships to disclose.

Pediatric phase I trial and pharmacokinetic (PK) study of dasatinib: A report from the Children’s Oncology Group

14094

Background: Dasatinib is an orally-available tyrosine kinase inhibitor with low-nanomolar activity against SRC-family kinases, BCR-ABL, c-KIT, EPHA2, and the PDGFβ receptor. Methods: A phase I study of dasatinib administered as a single agent in pediatric patients with refractory solid tumors or imatinib refractory Ph+ leukemias is being performed. Dasatinib dose levels of 50, 65, 85 and 110 mg/m2/dose, administered orally twice daily for 28 consecutive days, are being studied. Courses repeat without interruption. Results: 8 pts with solid tumor and 3 pts with Ph+ leukemia (median age 11 yrs, range 7–17) have been enrolled, of whom 7 are fully evaluable for toxicity. At the 50 and 65 mg/m2 dose levels, 0/3 and 0/1 pts experienced DLT. 1 of 3 pts with CML treated at the 50 mg/m2 dose level had Gr 4 hypokalemia. In 4 pts studied at the 50 mg/m2 dose level, the median (range) apparent dasatinib clearance was 238.5 L/hr (220.7 - 332.7), terminal half-life was 2.3 hrs (2.2 - 3.1), and the median Cmax was 55.5 ng/ml (36.0 - 161.1). Conclusions: Dasatinib is well tolerated at a dose of 50 mg/m2 BID on a continuous 28 day dose schedule in pediatric patients. Preliminary PK analysis suggests that drug disposition is similar to that observed in adults. Dose escalation and PK studies are continuing.

No significant financial relationships to disclose.

Effect of microscopic residual tumor (MRT) at surgical margin of resection (SMR) in ductal carcinoma in-situ (DCIS) on survival of non-Hispanic white women in central Pennsylvania (PA)

10706

Background: Few studies that have investigated the long-term effect of MRT in DCIS, have demonstrated conflicting results. Mount Nittany Medical Center (MNMC) is located in an agricultural, ethnically-homogenous (Non-Hispanic White) county in PA. To the best of our knowledge, there have been no similar studies conducted on such populations. Our study has investigated the effect of MRT at SMR on overall survival (OS) and event-free survival (EFS) of patients with DCIS. Methods: All women diagnosed with DCIS from 04/1992 to 06/2005 at MNMC were deemed eligible. Log-rank statistics and Cox proportional hazard models (CPHM) were used for obtaining survival rates. Results: Of the 266 eligible women analysis were performed on 167 women (age range 33–89 years; median 56 years) with complete data on diagnosis, surgical margins and treatment modalities. With median follow-up time of 4.6 years (range 0.03–11.6years), 148 (88.6%) patients had no residual tumor at SMR. 78 (46.7%) patients received radiation therapy (RT) ± hormonal therapy (HT), 42 (25.2%) received HT ± RT. The CPHM demonstrated no statistical significance of MRT on OS (hazard ratio 2.9, p = 0.19), and EFS (hazard ratio = 1.9, p = 0.43) after adjusting for treatment and age. Univariate 5-year OS rate in patients with no MRT was 93.9% (95% confidence interval (CI) 87.6% to 97.1%), versus 89.2% (95% CI 63.1% to 97.2%) in patients with MRT (p-value = 0.38). Five-year EFS was observed to be 92.6% (95% CI 85.6% to 96.3%) in patients with no MRT, versus 89.2% (95% CI 63.1% to 97.2%) in patients with MRT (p-value = 0.49). Conclusions: In our study, patients with DCIS who have MRT at surgical margin of resection have a 2.9 times the risk of death and 1.9 times the risk of recurrence as compared to patients with no MRT. However, this difference is statistically not significant over time.

No significant financial relationships to disclose.

Pediatric phase 1 study of pemetrexed: A report from the Children’s Oncology Group

9019

Background: Pemetrexed is a new multi-targeted antifol that inhibits enzymes involved in the de novo biosynthesis of thymidine and purine nucleotides. Methods: A phase 1 dose escalation and pharmacokinetic study (PK) was performed in children with refractory solid tumors to define the dose limiting toxicities (DLTs) and a recommended phase 2 dose. Pemetrexed was administered as a 10 min iv infusion every 21 days. All patients received folic acid (400 mcg/day po), vitamin B12 (500–1000 mcg every 3rd course IM) and dexamethasone (0.1 mg/kg/dose bid × 3 days each course) . Cohorts of 3 to 6 children were enrolled at dose levels of 400, 520, 670, 870, 1,130, 1,470, 1,910 and 2,480 mg/m2. DLT was defined as any Gr. 3 or 4 non-hematological toxicity (except nausea/vomiting, alopecia, or AST/ALT elevation that returns to Gr. 1), Gr. 4 neutropenia or Gr. 4 thrombocytopenia ≥ 7 days. Results: 33 subjects (31 fully evaluable for toxicity), median age of 12 yrs (range, 1–21), with diagnoses including osteosarcoma (12), Ewing’s sarcoma (3), hepatoblastoma (2), renal cell carcinoma (2), brainstem glioma (3), glioma (3), and other (n=8) were enrolled. DLT occurred in 1/6 patients at 1,470 mg/m2 (Gr. 3 AST and ALT), and in 2/4 at 2,480 mg/m2 (Gr. 3 ANC and Gr. 3 rash in both). Other DLTs at 2,480 mg/m2 that occurred in 1 patient included Gr. 3 diarrhea and rectal hemorrhage, and Gr. 4 thrombocytopenia, lipase, GGT, hypophosphatemia, hypokalemia and hyponatremia. At 1,910 mg/m2, 0/6 patients had DLT. The median number of courses administered was 1 (range 1 to 17). No CRs or PRs have been observed. Results of PK and other correlative studies will be presented. Conclusions: The recommended phase 2 dose of pemetrexed for children and adolescents with recurrent solid tumors is 1,910 mg/m2 administered q21 days with dexamethasone, folic acid and B12 supplementation. A phase II COG study is planned.

No significant financial relationships to disclose.

Effect of microscopic residual tumor (MRT) at surgical margin of resection (SMR) in invasive breast cancer (IBC) on survival of non-Hispanic white women in central Pennsylvania (PA)

10569

Background: Few studies that have investigated the long-term effect of MRT in IBC, have demonstrated conflicting results. Mount Nittany Medical Center (MNMC) is located in an agricultural, ethnically-homogenous (Non-Hispanic White) county in PA. To the best of our knowledge, there have been no similar studies conducted on such populations. Our study has investigated the effect of MRT at SMR on overall survival (OS) and event-free survival (EFS) of patients with IBC. Methods: All women diagnosed with IBC from 04/1992 to 06/2005 at MNMC were deemed eligible. Log-rank statistics and Cox proportional hazard models (CPHM) were used for obtaining survival rates. Results: Of the 939 eligible women analysis were performed on 651 women (age range 27–94 years; median 62 years) with complete data on diagnosis, surgical margins and treatment modalities. With a median follow-up time of 4 years (range 0.01–11.3 years), 390 (59.9%), 214 (32.8%), 47 (7.2%) women had stage I, II and III tumor respectively; 540 (83%) patients had no residual tumor at SMR. 484 (74.4%) patients received radiation therapy (RT) ± chemotherapy (CT) and/or hormonal therapy (HT), 383 (58.8%) received HT ± CT and/or RT and 229 (35.2%) received CT ± RT and/or HT. The CPHM demonstrated no statistical significance of MRT on OS (hazard ratio 1.54, p = 0.07), and EFS (hazard ratio = 1.54, p = 0.07) after adjusting for treatment, stage and age. Univariate 10-year OS rate in patients with no MRT was 72.7% (95% confidence interval (CI) 63.1% to 80.1%), versus 61.2% (95% CI 45.3% to 73.8%) in patients with MRT (p-value = 0.07). Ten-year EFS was observed to be 68.9% (95% CI 59.1% to 76.8%) in patients with no MRT, versus 60.8% (95% CI 45.1% to 73.2%) in patients with MRT (p-value = 0.08). Conclusion: In our study, patients with IBC with MRT at SMR have a 1.5 times the risk of death or recurrence as compared to patients with no MRT. However, this difference is statistically not significant over time.

No significant financial relationships to disclose.

A phase I study of bevacizumab in children with refractory solid tumors: A Children’s Oncology Group study

9017

Background: Bevacizumab is a humanized monoclonal antibody targeting the vascular endothelial growth factor (VEGF-A) that has demonstrated significant growth inhibition in several pre-clinical models of pediatric solid tumors. However, the agent has never been tested in pediatric patients. Methods: A phase I dose escalation study in children with refractory solid tumors was conducted to define the dose limiting toxicities (DLTs), and to determine the pharmacokinetics (PK) and recommended phase II dose of bevacizumab administered by IV infusion every 2 weeks in 28-day cycles. Cohorts were enrolled at dose levels of 5, 10, and 15 mg/kg; the final dose level was expanded to include at least 3 children <6 years of age. Serial blood samples were collected for PK, plasma VEGF concentration, and circulating mature and progenitor endothelial cells (CECs/CEPs). Results: 20 patients (10 male), median age 13 yrs (range 1–21), were enrolled at dose levels 5 (n=3), 10 (n=3), and 15 (n=14) mg/kg. 18 patients were fully evaluable for toxicity (one withdrew consent prior to treatment and the second was removed for rapid disease progression). A total of 67 cycles were administered with a median of 3 per patient (range 1–16). Treatment was well tolerated and no DLTs were observed. Only one grade 3 toxicity, lymphopenia, was attributed to drug. Non-dose limiting, grade 1–2 toxicities included infusional reaction (n=3), rash (n=3), mucositis (n=2), and proteinuria (n=3). There was no hypertension, hemorrhage or thrombosis reported. There were no partial or complete responses; 3 pts with Ewings and 2 pts with soft tissue sarcoma had disease stabilization for > 3 months. The serum exposure to bevacizumab as measured by AUC appeared to increase in proportion to dose. The median clearance of bevacizumab was 4.1 ml/day/kg (range 3.2–15.9), and the median T1/2 was 11.8 days (range 3.9–14.6). In some patients, a rapid rate of rise in plasma VEGF, increase in mature CECs or decrease in CEPs was observed. Conclusion: Bevacizumab at doses up to 15mg/kg every two weeks is well tolerated in children with solid tumors.

No significant financial relationships to disclose.