Author Contributions: Dr Metzger had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Metzger, Hudson, Link.
Acquisition of data: Metzger, Billett, Weinstein, Hudson, Larsen, Friedmann, Howard, Link.
Analysis and interpretation of data: Metzger, Billett, Billups, Wu, Weinstein, Hudson, Larsen, Friedmann, Howard, Donaldson, Krasin, Yock, Tarbell, Link
Drafting of the manuscript: Metzger, Billett, Weinstein, Hudson, Larsen, Friedmann, Howard, Donaldson, Krasin, Yock, Tarbell, Link.
Critical revision of the manuscript for important intellectual content: Metzger, Billett, Weinstein, Larsen, Hudson, Friedmann, Howard, Wu, Marcus, Billups, Donaldson, Krasin, Kun, Yock, Tarbell, Link.
Statistical analysis: Metzger, Billups, Wu.
Obtained funding: Metzger, Hudson.
Administrative, technical, or material support: Metzger.
Study supervision: Metzger, Link, Hudson, Link.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Metzger reported that she has received funding for an international conference unrelated to the study from Seattle Genetics, Amgen, and Millennium. Dr Kun reported that he is a board member for the National Cancer Institute Brain Malignancies steering committee. Dr Link reported that he has received funding for his institution from American Society for Clinical Oncology for his role as president, and from St Jude Children's Research Hospital for patient enrollment on this study and for his roles on the Scientific Advisory Board and Cancer Center Advisory Board. Dr Link reported that he receives support from Seattle Genetics for clinical trial participation (unrelated to this study) and Pfizer (unrelated to this study). No other financial disclosures were reported.
Funding/Support: Study supported by grant CA-21765 from the National Institutes of Health Cancer Support Core Grant and the American Lebanese Syrian Associated Charities.
Role of the Sponsor: The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
Previous Presentation: Presented in part at the annual meeting of the American Society of Clinical Oncology (ASCO), June 2011, Chicago, Illinois.
Independent Statistical Analysis: Dr Wu performed the statistical analysis of the data with the assistance of Ms Billups.
Data and Safety Monitoring Board: Frank Baylis, MD, chair of the data and safety monitoring board, is Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania and Director of Clinical Research, Center for Childhood Cancer Research in Philadelphia. James Boyett, PhD, St Jude data and monitoring board executive secretary, St Jude Children's Research Hospital, Memphis, Tennessee.
Additional Contributions: We thank David Galloway, BS, ELS, staff scientific editor at St Jude Children's Research Hospital, for his editorial support. His services are available to all investigators free of charge.