Lisa M. McGregor

UGT1A1 Promoter Genotype Correlates With SN-38 Pharmacokinetics, but Not Severe Toxicity in Patients Receiving Low-Dose Irinotecan

PURPOSE To study the association between UDP-glucuronosyltransferase 1A1 (UGT1A1) genotypes and severe toxicity as well as irinotecan disposition in pediatric patients with solid tumors receiving low-dose, protracted irinotecan (15 to 75 mg/m2 daily for 5 days for 2 consecutive weeks). PATIENTS AND METHODS Seventy-four patients on five institutional clinical trials received irinotecan (15 to 75 mg/m2) daily intravenously or orally for 5 days for 2 consecutive weeks. Genomic DNA was genotyped for UGT1A1*28, and patients were designated as 6/6, 6/7, or 7/7 depending on the number of TA repeats in the UGT1A1 promoter region. Patients were evaluated for gastrointestinal and hematologic toxicity, as well as baseline and maximal serum bilirubin levels. Toxicity and pharmacokinetic results were evaluated during courses 1 and 2 of irinotecan therapy. RESULTS The frequencies of 6/6, 6/7, and 7/7 genotypes were 27 (36.5%), 36 (48.6%), and 9 (12.2%) of 74 patients, respectively. Patients with 7/7 genotype had a statistically greater baseline total bilirubin than patients with 6/6 or 6/7 genotype (P = .005). UGT1A1*28 genotype was not associated with grade 3 and 4 neutropenia (P = .21 for course 1; P = .23 for course 2) or diarrhea (P = .176 for course 1; P = .87 for course 2). However, patients with the 7/7 genotype tended to have higher SN-38 area under the plasma time-concentration curve (AUC) values and lower SN-38G/SN-38 AUC ratios. CONCLUSION Severe toxicity was not increased in pediatric patients with the 7/7 genotype when treated with a low-dose protracted schedule of irinotecan. Therefore, UGT1A1 genotyping is not a useful prognostic indicator of severe toxicity for patients treated with this irinotecan dosage and schedule.

Phase I Trial of a Novel Anti-GD2 Monoclonal Antibody, Hu14.18K322A, Designed to Decrease Toxicity in Children With Refractory or Recurrent Neuroblastoma

PURPOSE The addition of immunotherapy, including a combination of anti-GD2 monoclonal antibody (mAb), ch14.18, and cytokines, improves outcome for patients with high-risk neuroblastoma. However, this therapy is limited by ch14.18-related toxicities that may be partially mediated by complement activation. We report the results of a phase I trial to determine the maximum-tolerated dose (MTD), safety profile, and pharmacokinetics of hu14.18K322A, a humanized anti-GD2 mAb with a single point mutation (K322A) that reduces complement-dependent lysis. PATIENTS AND METHODS Eligible patients with refractory or recurrent neuroblastoma received escalating doses of hu14.18K322A ranging from 2 to 70 mg/m(2) per day for 4 consecutive days every 28 days (one course). RESULTS Thirty-eight patients (23 males; median age, 7.2 years) received a median of two courses (range, one to 15). Dose-limiting grade 3 or 4 toxicities occurred in four of 36 evaluable patients and were characterized by cough, asthenia, sensory neuropathy, anorexia, serum sickness, and hypertensive encephalopathy. The most common non-dose-limiting grade 3 or 4 toxicities during course one were pain (68%) and fever (21%). Six of 31 patients evaluable for response by iodine-123 metaiodobenzylguanidine score had objective responses (four complete responses; two partial responses). The first-course pharmacokinetics of hu14.18K322A were best described by a two-compartment linear model. Median hu14.18K322A α (initial phase) and β (terminal phase) half-lives were 1.74 and 21.1 days, respectively. CONCLUSION The MTD, and recommended phase II dose, of hu14.18K322A is 60 mg/m(2) per day for 4 days. Adverse effects, predominately pain, were manageable and improved with subsequent courses.

Tyrosine Kinase Inhibitor Enhances the Bioavailability of Oral Irinotecan in Pediatric Patients With Refractory Solid Tumors

PURPOSE To assess the maximum-tolerated dosages (MTDs), and dose-limiting toxicities (DLTs) of the epidermal growth factor receptor inhibitor gefitinib and of intravenous (IV) irinotecan when administered together in children with refractory solid tumors. To assess the effect of gefitinib on the pharmacokinetics of IV irinotecan and on the bioavailability of a single oral dose of irinotecan. PATIENTS AND METHODS IV irinotecan (15 or 20 mg/m(2)) was given daily for 5 days of 2 consecutive weeks. Oral gefitinib (150 or 112.5 mg/m(2)) was concomitantly given daily for 12 or 21 days. A single oral dose of irinotecan was given on day 9 of course 2 to allow pharmacokinetic analysis. RESULTS The study enrolled 29 patients with recurrent solid tumors. The 21-day regimen of oral gefitinib with irinotecan was not tolerated. Diarrhea was the most common DLT. The MTD of the combination regimen was 15 mg/m(2)/d of IV irinotecan for 5 days of 2 consecutive weeks and 112.5 mg/m(2)/d of gefitinib given for 12 days. Gefitinib increased the bioavailability of oral irinotecan by four-fold over that observed in historical controls (median, 0.09 v 0.42; P < .000001), reducing the apparent clearance (an inverse measure of exposure) of irinotecan and SN-38 by 37% and 38%, respectively (P < .0001). A partial response was observed in a patient with refractory Ewing sarcoma. CONCLUSION IV irinotecan given with 12 days of oral gefitinib is well tolerated in children. We observed one partial response. Gefitinib significantly enhances the bioavailability of oral irinotecan. This combination warrants further investigation, particularly with orally administered irinotecan.

Phase I and Clinical Pharmacology Study of Bevacizumab, Sorafenib, and Low-dose Cyclophosphamide in Children and Young Adults with Refractory/Recurrent Solid Tumors

Purpose: To determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLT), pharmacokinetics, and pharmacodynamics of sorafenib, bevacizumab, and low-dose oral cyclophosphamide in children and young adults with recurrent/refractory solid tumors. Experimental Design: Sorafenib dose was escalated from 90 to 110 mg/m2 twice daily with fixed doses of bevacizumab at 5 mg/kg every 3 weeks and cyclophosphamide at 50 mg/m2 daily. Once sorafenibs MTD was established, bevacizumab dose was escalated. Each course was of 21 days. Pharmacokinetics and pharmacodynamics studies were conducted during the first course. Results: Nineteen patients (11 males; median age, 9.2 years) received a median of four courses (range, 1–23). DLTs during course 1 included grade 3 rash (two), increased lipase (one), anorexia (one), and thrombus (one). With an additional 71 courses of therapy, the most common toxicities ≥ grade 3 included neutropenia (nine), lymphopenia (nine), and rashes (four). Five of 17 evaluable patients had partial tumor responses, and five had disease stabilization (>2 courses). Median day 1 cyclophosphamide apparent oral clearance was 3.13 L/h/m2. Median day 1 sorafenib apparent oral clearance was 44 and 39 mL/min/m2 at the 2 dose levels evaluated, and steady-state concentrations ranged from 1.64 to 4.8 mg/L. Inhibition of serum VEGF receptor 2 (VEGFR2) was inversely correlated with sorafenib steady-state concentrations (P = 0.019). Conclusion: The recommended phase II doses are sorafenib, 90 mg/m2 twice daily; bevacizumab, 15 mg/kg q3 weeks; and cyclophosphamide, 50 mg/m2 once daily. This regimen is feasible with promising evidence of antitumor activity that warrants further investigation. Clin Cancer Res; 19(1); 236–46. ©2012 AACR.

The impact of early resection of primary neuroblastoma on the survival of children older than 1 year of age with stage 4 disease : The St. Jude children's research hospital experience

It remains unclear whether primary tumor resection benefits patients with metastatic neuroblastoma. The authors assessed the impact of extent and timing of resection on outcome in these patients.

A novel EWSR1-CREB3L1 fusion transcript in a case of small cell osteosarcoma†

Cellular morphology of small cell osteosarcoma, an aggressive variant of osteosarcoma, is similar to Ewing sarcoma, but its molecular pathogenesis is largely unknown. We report the case of a 12‐year‐old girl with multifocal small cell osteosarcoma positive for the Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangement by interphase fluorescent in situ hybridization and negative for EWSR1‐FLI1, EWSR1‐ERG, and EWSR1‐WT1 fusion transcripts by reverse transcriptase PCR. Rapid amplification of cDNA ends revealed exon 6 of the cAMP‐responsive element binding protein 3‐like 1 gene (CREB3L1, also known as “OASIS,” NM_52854.2) fused in‐frame to the EWSR1 exon 11, consistent with the EWSR1‐CREB3L1 fusion transcript expressed in tumor tissue. The corresponding chimeric gene was confirmed by amplification and subsequent sequencing of the genomic breakpoint between introns 11 and 5 of EWSR1 and CREB3L1, respectively. An ∼70 kDa product in the tumor tissue lysate reacted with the CREB3L1 carboxyterminal antibody, consistent with a 656‐amino acid predicted chimeric protein. Immunohistochemistry with the same antibody showed signal translocation from the physiologic perinuclear compartment observed in glia and unrelated osteoblasts to nuclei of tumor cells, consistent with the likely function of EWSR1‐CREB3L1 as a transcriptional regulator predicted by its structure. This is the first report of a fusion transcript in osteogenic sarcoma; it demonstrates a relation between molecular mechanisms of small cell osteogenic and Ewing sarcomas. The 3′‐end partner and the inferred structure of EWSR1‐CREB3L1, however, are different from those of Ewing sarcoma, suggesting different targets of the new oncogene.

Dose escalation of intravenous irinotecan using oral cefpodoxime: A phase I study in pediatric patients with refractory solid tumors

Administration of an oral cephalosporin allowed advancement of the dosage of oral irinotecan. This study investigates whether administration of an oral cephalosporin increases the maximum tolerated dose (MTD) of intravenous irinotecan.

Intensity modulated radiation therapy provides excellent local control in high‐risk abdominal neuroblastoma

Locoregional failure is a significant concern in patients with high‐risk abdominal neuroblastoma (NB) receiving radiotherapy. Locoregional control outcomes were studied in children with NB receiving intensity modulated radiotherapy (IMRT).

Avoiding misdiagnosing neuroblastoma as Wilms tumor

PURPOSE Although occasionally difficult, distinguishing abdominal neuroblastoma (NBL) from Wilms tumor (WT) at presentation is important, as surgical management differs significantly. We reviewed our 20-year experience (1987-2006) treating patients with NBL, focusing on those with an initial diagnosis of WT, to determine presenting features that would have suggested the correct preoperative diagnosis. METHODS Retrospective case cohort study reviewing charts and imaging of patients with NBL initially diagnosed clinically with WT. Preoperative symptoms, laboratory studies, and imaging were evaluated. Similar variables were assessed in the 20 patients with WT most recently treated at our institution. RESULTS Nine patients with NBL were identified as those who had an exploratory laparotomy with a preoperative diagnosis of WT; 8 underwent nephrectomy at exploration. Children with NBL had symptoms such as fever and weight loss at presentation (67%) more often than patients with WT (20%). Preoperative computed tomography demonstrated intratumoral calcifications, vascular encasement, or both in 78% of patients with NBL but were never seen in WT patients. Of interest, preoperative urinary catecholamines were elevated in 5 patients ultimately diagnosed with NBL. CONCLUSION Although NBL can be mistaken for WT at presentation, the presence of constitutional symptoms, or intratumoral calcification or vascular encasement on preoperative imaging should heighten suspicion for NBL. In addition, laboratory evaluation, including urinary catecholamines, should be completed before surgery when the etiology of an abdominal tumor is uncertain.

Disease control intervals in high‐risk neuroblastoma

Current salvage therapy for recurrent high‐risk neuroblastoma is rarely curative. Assessment of the effectiveness of new, primarily cytostatic agents requires the redefinition of study endpoints to reflect disease stabilization rather than tumor response or regression. The intervals of disease control in the patients in the current study with recurrent neuroblastoma were characterized to provide comparison criteria for exploratory studies of new agents.