Keith J. August

The use of zoledronic acid in pediatric cancer patients

The third generation bisphosphonate zoledronic acid has demonstrated efficacy in reducing skeletal‐related events in adult patients with multiple cancer types that have skeletal disease. The use of zoledronic acid in pediatric oncology patients with bone metastases for the purpose of reducing pain, improving bone strength and altering the progression of metastatic disease has not been thoroughly evaluated.

A Phase I Study of Quizartinib Combined with Chemotherapy in Relapsed Childhood Leukemia: A Therapeutic Advances in Childhood Leukemia & Lymphoma (TACL) Study.

Purpose: To determine a safe and biologically active dose of quizartinib (AC220), a potent and selective class III receptor tyrosine kinase (RTK) FLT3 inhibitor, in combination with salvage chemotherapy in children with relapsed acute leukemia. Experimental Design: Quizartinib was administered orally to children with relapsed AML or MLL-rearranged ALL following 5 days of high-dose cytarabine and etoposide (AE). A 3+3 dose escalation design was used to identify a safe and biologically active dose. Plasma inhibitory assay (PIA) testing was performed weekly to determine biologic activity. Results: Toxicities were consistent with intensive relapsed leukemia regimens. One of 6 patients experienced a dose-limiting toxicity (DLT) at 40 mg/m2/day (elevated lipase) and 1 of 9 had a DLT (hyperbilirubinemia) at the highest tested dose of 60 mg/m2/day. Of 17 response evaluable patients, 2 had complete response (CR), 1 complete response without platelet recovery (CRp), 1 complete response with incomplete neutrophil and platelet recovery (CRi), 10 stable disease (SD), and 3 progressive disease (PD). Of 7 FLT3-ITD patients, 1 achieved CR, 1 CRp, 1 Cri, and 4 SD. FLT3-ITD patients, but not FLT3 wild-type (WT) patients, had significantly lower blast counts post-quizartinib. FLT3 phosphorylation was completely inhibited in all patients. Conclusions: Quizartinib plus intensive chemotherapy is well tolerated at 60 mg/m2/day with near complete inhibition of FLT3 phosphorylation in all patients. The favorable toxicity profile, pharmacodynamic activity, and encouraging response rates warrant further testing of quizartinib in children with FLT3-ITD AML. Clin Cancer Res; 22(16); 4014–22. ©2016 AACR.

Comparison of hypersensitivity reactions to PEG-asparaginase in children after intravenous and intramuscular administration.

Introduction: Polyethylene-glycolated (PEG)-asparaginase (PEG-ASP) is a crucial component of pediatric acute lymphoblastic leukemia therapy. Although hypersensitivity reactions to PEG-ASP occur less frequently than with other formulations, they are not uncommon and have an adverse impact on patient outcomes. Intravenous (IV) administration of PEG-ASP reduces patient pain and anxiety and is being used with increasing frequency in children. Materials and Methods: A retrospective review was performed to compare the incidence of hypersensitivity reactions to PEG-ASP in children when administered either by intramuscular (IM) or IV routes between January 2006 and May 2008. Results: Of 68 patients studied, 7 experienced a hypersensitivity reaction (10.3%). Two of 16 patients (12.5%) who received only IV PEG-ASP and 3 of 27 patients (11.1%) exposed to only IM PEG-ASP experienced a hypersensitivity reaction. Severe reactions (grade 3 or 4) occurred only once after 119 total doses (0.8%) of IV PEG-ASP and once after 215 total doses (0.5%) of IM PEG-ASP (P=1.0). Thrombosis or pancreatitis were rare and were not increased after IV PEG-ASP administration. Discussion: IV PEG-ASP is well tolerated and does not result in a significant increase in the incidence of hypersensitivity reactions in children.

Late Effects of Childhood Leukemia Therapy

As survival rates for children treated for childhood cancers become significantly better, the focus is increasingly on determining the late effects of treatments and the best ways to monitor for them and prevent their occurrence. This review focuses on recent literature discussing the late effects of treatment in patients treated for acute myeloid leukemia and acute lymphoblastic leukemia during childhood. The late effects of therapy for childhood leukemia include secondary malignancy, cardiotoxicity, obesity, endocrine abnormalities, reproductive changes, neurocognitive deficits, and psychosocial effects. As clinicians have become more aware of the late effects of therapy, treatment regimens have been changed to decrease late effects, but patients still require long-term follow-up for their prevention and treatment.

A phase 1 study of the CXCR4 antagonist plerixafor in combination with high-dose cytarabine and etoposide in children with relapsed or refractory acute leukemias or myelodysplastic syndrome: A Pediatric Oncology Experimental Therapeutics Investigators' Consortium study (POE 10-03).

Plerixafor, a reversible CXCR4 antagonist, inhibits interactions between leukemic blasts and the bone marrow stromal microenvironment and may enhance chemosensitivity. A phase 1 trial of plerixafor in combination with intensive chemotherapy in children and young adults with relapsed or refractory acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and myelodysplastic syndrome (MDS) was performed to determine a tolerable and biologically active dose.

Caregiver survey results related to handling of oral chemotherapy for pediatric patients with acute lymphoblastic leukemia.

Background: Oral chemotherapy is commonly administered in the home; however, there may be harmful effects on healthy individuals who handle these medications. Caregivers of pediatric patients were surveyed to establish educational needs for safe handling of oral chemotherapy agents. Methods: An 11-question self-report survey was developed to characterize handling practices for patients in maintenance therapy for acute lymphoblastic leukemia related to caregiver education, use of protective gear, preparation, and disposal of oral chemotherapy agents. Results: Fifty questionnaires were collected. Seventy-two percent of responders reported receiving instruction on safe handling of oral chemotherapy. Ninety percent of responders reported that they did not utilize protective gear during preparation of oral chemotherapy. Although tablet crushers were designated for use with oral chemotherapy by 61% of responders, 22% used the same device to crush other nonchemotherapy medications. The majority of responders disposed of medication waste with regular garbage or poured the remainder down the sink. Conclusions: Caregiver survey responses demonstrated that personal safeguards were not routinely utilized by pediatric caregivers while handling oral chemotherapy. Future educational efforts should be directed to improve caregiver understanding related to the use of protective equipment, designation of supplies for use with chemotherapy agents, and safe disposal.

Relative Defects in Mucosal Immunity Predict Acute Graft-Versus-Host Disease

Impairment of gut mucosal immunity by the transplant process could facilitate translocation of commensal bacteria and thereby augment the graft-versus-host response. To begin to assess the influence of gut mucosal immunity on the development of acute graft-versus-host disease (GVHD), we conducted a prospective study in 24 pediatric allogeneic hematopoietic cell transplant recipients, assessing 4 fecal markers of mucosal immunity: calprotectin, soluble CD8 (sCD8), soluble intracellular adhesion molecule 1, and β-defensin-2. Stool samples were collected prospectively on transplant days 0, +5, +10, and +15 and analyzed by ELISA. Lower levels on day +5 (calprotectin and β-defensin-2) and day +10 (calprotectin, β-defensin-2, and sCD8) were associated with subsequent acute GVHD. The most striking difference was with calprotectin on day +10. Patients with levels below 424 mg/kg had an incidence of 77.8%, whereas those with levels above this threshold had a cumulative incidence of 0% (P = .002). Relative defects in gut mucosal immunity may be important in the pathogenesis of acute GVHD.

Rifaximin for preventing acute graft-versus-host disease: impact on plasma markers of inflammation and T-cell activation.

In murine allogeneic hematopoietic cell transplantation models, inhibiting bacterial translocation stemming from conditioning-induced damage to the gut mucosa abrogates inflammatory stimulation of donor T cells, preventing acute graft-versus-host disease (AGVHD). We conducted a phase I trial to begin testing the hypothesis that rifaximin, a broadly acting oral antibiotic, would reduce systemic inflammation and T-cell activation. We administered rifaximin to 20 adolescents and younger adults (day –10 through day +30) receiving intensive conditioning. We measured the plasma level of interleukin-6, as a marker of conditioning-induced inflammation, and the levels of soluble tumor necrosis factor receptor-1 and soluble interleukin-2 receptor, as surrogate markers of AGVHD. We formed a historical control group (n=24), from a previous study of biomarkers in AGVHD. The increase in the treatment group’s mean interleukin-6 level from baseline to day 0 was 73% less than that in the control group (P=0.006). The increase from baseline to day 15 in the treatment group’s mean soluble tumor necrosis factor-1 and soluble interleukin-2 receptor levels was similar to the control group. Incidences of grade 2 to 4 AGVHD also did not differ. This suggests that rifaximin may abrogate bacterial translocation and resultant inflammation, but in alternative donor transplants this does not prevent downstream activation of donor T cells.

Parental Perceptions of Obesity and Obesity Risk Associated With Childhood Acute Lymphoblastic Leukemia.

The prevalence of obesity and related comorbidities in survivors of childhood acute lymphoblastic leukemia (ALL) is well established and ranges anywhere from 29% to 69% depending on the study. We sought to explore the awareness of parents of survivors of childhood ALL regarding the increased risk of obesity and their perceptions regarding the overall health of their child. One hundred twenty-one parents of 99 survivors of pediatric ALL completed surveys regarding perceptions of obesity risk in survivors. Eighty percent of parents of overweight and obese survivors correctly identified their child as “a little overweight” or “overweight.” Few parents recalled discussing weight gain (21%) or obesity risk (36%) with their practitioner. Parents that did recall having these discussions and/or reported a decreased level of posttherapy activity in their child were more likely to be concerned about their child’s weight status. Improved awareness and education regarding the risk of obesity and associated comorbid conditions may provide an avenue for future prevention of obesity in survivors of pediatric ALL. Discussion and education regarding a healthy lifestyle, including proper diet and exercise, should be incorporated early in routine patient visits.

Early Discharge of Neutropenic Pediatric Oncology Patients Admitted With Fever

Fever and neutropenia (FN) is a common complication of pediatric oncology therapy and accounts for a large number of hospital admissions. Standard therapy for FN includes hospital admission and empiric antibiotics. Strict adherence to this practice leads to prolonged hospitalizations that may be unnecessary for patients at low risk of having an underlying significant infection.