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Dive into the research topics where David R. Freyer is active.

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Featured researches published by David R. Freyer.


Genetics in Medicine | 2009

Clinical outcomes after long-term treatment with alglucosidase alfa in infants and children with advanced Pompe disease

Marc Nicolino; Barry J. Byrne; J. E. Wraith; Nancy Leslie; Hanna Mandel; David R. Freyer; Georgianne L. Arnold; Eniko K. Pivnick; C. J. Ottinger; Peter Robinson; John Charles A Loo; M Smitka; Philip Jardine; Luciano Tatò; Brigitte Chabrol; Shawn E. McCandless; Shigemi Kimura; L. Mehta; Deeksha Bali; Alison Skrinar; Claire Morgan; Lakshmi Rangachari; Deya Corzo; Priya S. Kishnani

Purpose: A clinical trial was conducted to evaluate the safety and efficacy of alglucosidase alfa in infants and children with advanced Pompe disease.Methods: Open-label, multicenter study of IV alglucosidase alfa treatment in 21 infants 3–43 months old (median 13 months) with minimal acid α-glucosidase activity and abnormal left ventricular mass index by echocardiography. Patients received IV alglucosidase alfa every 2 weeks for up to 168 weeks (median 120 weeks). Survival results were compared with an untreated reference cohort.Results: At study end, 71% (15/21) of patients were alive and 44% (7/16) of invasive-ventilator free patients remained so. Compared with the untreated reference cohort, alglucosidase alfa reduced the risk of death by 79% (P < 0.001) and the risk of invasive ventilation by 58% (P = 0.02). Left ventricular mass index improved or remained normal in all patients evaluated beyond 12 weeks; 62% (13/21) achieved new motor milestones. Five patients were walking independently at the end of the study and 86% (18/21) gained functional independence skills. Overall, 52% (11/21) of patients experienced infusion-associated reactions; 95% (19/20) developed IgG antibodies to recombinant human lysosomal acid α-glucosidase; no patients withdrew from the study because of safety concerns.Conclusions: In this population of infants with advanced disease, biweekly infusions with alglucosidase alfa prolonged survival and invasive ventilation-free survival. Treatment also improved indices of cardiomyopathy, motor skills, and functional independence.


The Journal of Pediatrics | 1996

Juvenile xanthogranuloma: Forms of systemic disease and their clinical implications

David R. Freyer; Rosemarie Kennedy; Bruce Bostrom; Gloria Kohut; Louis P. Dehner

OBJECTIVE Juvenile xanthogranuloma (JXG) with systemic (extracutaneous) involvement is a rare histiocytic disorder in which significant morbidity and occasional deaths may occur. The objective of this study was to characterize the spectrum of anatomic involvement, associated clinical problems, and management considerations in children with systemic JXG. STUDY DESIGN Two current cases and literature reports of 34 children with various forms of systemic AG were analyzed with respect to age, clinical presentation, site(s) of involvement, therapy, and outcome. RESULTS The median age of the 36 patients was 0.3 years (range, birth to 12 years). Symptoms were usually referable to bulky or infiltrative disease. Twenty patients had disease in two or more sites. Cutaneous lesions were present in fewer than half the patients. The most frequent extracutaneous sites of disease were the subcutaneous soft tissue (12); central nervous system (8); liver/spleen (8); lung (6); eye/orbit, oropharynx, and muscle (4 each); with three or fewer instances of disease in each of several other sites. Most patients were treated with excision or had spontaneous regression (some with organ involvement). However, 12 patients received treatment that included radiation or systemic chemotherapy. Survivors, some with long-term disabilities, included young children who had received radiation therapy to the brain, eye, skin, or heart. Two patients died of disease. CONCLUSIONS Systemic AG may involve varying numbers and combinations of extracutaneous sites. The extent of disease should be determined in patients with AG who are suspected to have systemic involvement. In contrast to the cutaneous form, systemic AG may be associated with significant complications requiring aggressive medical care. When feasible, surgical excision of lesions may be curative. Optimal treatment for symptomatic, unresectable disease is currently undefined but should be selected to minimize toxic effects in these children who are typically younger than 1 year old at presentation.


Journal of Clinical Oncology | 2012

Randomized Study of Two Chemotherapy Regimens for Treatment of Low-Grade Glioma in Young Children: A Report From the Children's Oncology Group

Joann L. Ater; Tianni Zhou; Emiko J. Holmes; Claire Mazewski; Timothy N. Booth; David R. Freyer; Ken Lazarus; Roger J. Packer; Michael D. Prados; Richard Sposto; Gilbert Vezina; Jeffrey H. Wisoff; Ian F. Pollack

PURPOSE Surgery is curative therapy for pediatric low-grade gliomas (LGGs) in areas of the brain amenable to complete resection. However, LGGs located in areas where complete resection is not possible can threaten both function and life. The purpose of this study was to compare two chemotherapy regimens for LGGs in children younger than age 10 years for whom radiotherapy was felt by the practitioner to pose a high risk of neurodevelopmental injury. PATIENTS AND METHODS Previously untreated children younger than age 10 years with progressive or residual LGGs were eligible. Children were randomly assigned to receive carboplatin and vincristine (CV) or thioguanine, procarbazine, lomustine, and vincristine (TPCV). Children with neurofibromatosis are reported separately. Results Of 274 randomly assigned patients who met eligibility requirements, 137 received CV and 137 received TPCV. The 5-year event-free survival (EFS) and overall survival (OS) rates for all eligible patients were 45% ± 3.2% and 86% ± 2.2%, respectively. The 5-year EFS rates were 39% ± 4% for CV and 52% ± 5% for TPCV (stratified log-rank test P = .10; cure model analysis P = .007). On multivariate analysis, factors independently predictive of worse EFS and OS were younger age and tumor size greater than 3 cm(2). Tumor location in the thalamus was also associated with poor OS. CONCLUSION The difference in EFS between the regimens did not reach significance on the basis of the stratified log-rank test. The 5-year EFS was higher for TPCV on the basis of the cure model analysis. Differences in toxicity may influence physician choice of regimens.


Journal of Clinical Oncology | 2012

Platinum-Induced Ototoxicity in Children: A Consensus Review on Mechanisms, Predisposition, and Protection, Including a New International Society of Pediatric Oncology Boston Ototoxicity Scale

Penelope Brock; Kristin Knight; David R. Freyer; Kathleen C. M. Campbell; Peter S. Steyger; Brian W. Blakley; Shahrad Rod Rassekh; Kay W. Chang; Brian J. Fligor; Kaukab Rajput; Michael Sullivan; Edward A. Neuwelt

PURPOSE The platinum chemotherapy agents cisplatin and carboplatin are widely used in the treatment of adult and pediatric cancers. Cisplatin causes hearing loss in at least 60% of pediatric patients. Reducing cisplatin and high-dose carboplatin ototoxicity without reducing efficacy is important. PATIENTS AND METHODS This review summarizes recommendations made at the 42nd Congress of the International Society of Pediatric Oncology (SIOP) in Boston, October 21-24, 2010, reflecting input from international basic scientists, pediatric oncologists, otolaryngologists, oncology nurses, audiologists, and neurosurgeons to develop and advance research and clinical trials for otoprotection. RESULTS Platinum initially impairs hearing in the high frequencies and progresses to lower frequencies with increasing cumulative dose. Genes involved in drug transport, metabolism, and DNA repair regulate platinum toxicities. Otoprotection can be achieved by acting on several these pathways and generally involves antioxidant thiol agents. Otoprotection is a strategy being explored to decrease hearing loss while maintaining dose intensity or allowing dose escalation, but it has the potential to interfere with tumoricidal effects. Route of administration and optimal timing relative to platinum therapy are critical issues. In addition, international standards for grading and comparing ototoxicity are essential to the success of prospective pediatric trials aimed at reducing platinum-induced hearing loss. CONCLUSION Collaborative prospective basic and clinical trial research is needed to reduce the incidence of irreversible platinum-induced hearing loss, and optimize cancer control. Wide use of the new internationally agreed-on SIOP Boston ototoxicity scale in current and future otoprotection trials should help facilitate this goal.


Journal of Clinical Oncology | 2010

Transition of Care for Young Adult Survivors of Childhood and Adolescent Cancer: Rationale and Approaches

David R. Freyer

PURPOSE Young adult survivors of childhood and adolescent cancer are an ever-growing population of patients, many of whom remain at lifelong risk for potentially serious complications of their cancer therapy. Yet research shows that many of these older survivors have deficient health-related knowledge and are not engaging in recommended health promotion and screening practices that could improve their long-term outcomes. The purpose of this review is to address these disparities by discussing how formal transition of care from pediatric to adult-focused survivorship services may help meet the unique medical, developmental, and psychosocial challenges of these young adults. DESIGN Literature review and discussion. RESULTS This article summarizes current research documenting the medical needs of young adult survivors, their suboptimal compliance with recommended follow-up, and the rationale, essential functions, current models, and innovative approaches for transition of follow-up care. CONCLUSION Systematic health care transition constitutes the standard of care for young adult survivors of childhood cancer. In developing a transitional care program, it is necessary to consider the scope of services to be provided, available resources, and other local exigencies that help determine the optimal model for use. Additional research is needed to improve health services delivery to this population. Effective advocacy is needed, particularly in the United States, to ensure the availability of uninterrupted health insurance coverage for survivorship services in young adulthood.


Pediatric Blood & Cancer | 2006

Models of care for survivors of childhood cancer

Debra L. Friedman; David R. Freyer; Gill Levitt

With improvements in therapy for childhood cancer, the expectation that most childhood cancer patients will survive and enter adulthood is a reality. There is clear evidence that survivors are at risk for adverse health‐related long‐term sequelae associated with their cancer and its treatment, requiring appropriate health care resources. What is less clear is how this health care should optimally be delivered. We review the functional and operational needs for long‐term follow‐up for childhood cancer survivors and present alternatives for models of care. Programs for childhood cancer survivors should provide mechanisms for monitoring and management of late effects, as well as support and advocacy for addressing psychosocial issues, health education, and assistance with financial concerns. Access to research is an important component as clinical care and research are integrally related. A multidisciplinary model that provides continuity of care throughout the disease course is optimal, providing transitions from acute anti‐neoplastic therapy to follow‐up and primary care, as well as from pediatric care to adult‐oriented care. There is no single best model of care for all childhood cancer survivors. In evaluating different models, considerations include available resources as well as the particular cancer population being served. Not all survivors require the same level of services and the service level requirement for individual patients may change with time. As outcome research progresses for childhood cancer survivors, methodological issues of optimal health care delivery for this population deserve to be the subject of such research. Pediatr Blood Cancer 2006;46:159–168.


Journal of Clinical Oncology | 2009

Young Adults With Acute Lymphoblastic Leukemia Have an Excellent Outcome With Chemotherapy Alone and Benefit From Intensive Postinduction Treatment: A Report From the Children's Oncology Group

James Nachman; Mei K. La; Stephen P. Hunger; Nyla A. Heerema; Paul S. Gaynon; Caroline A. Hastings; Leonard A. Mattano; Harland N. Sather; Meenakshi Devidas; David R. Freyer; Peter G. Steinherz; Nita L. Seibel

PURPOSE Patients 16 to 21 years of age with acute lymphoblastic leukemia (ALL) have an inferior outcome compared with younger children, leading some medical oncologists to advocate allogeneic stem-cell transplantation in first remission for these patients. We examined outcome for young adults with ALL enrolled onto the Childrens Cancer Group (CCG) 1961 study between 1996 and 2002. PATIENTS AND METHODS CCG 1961 entered patients with ALL 1 to 21 years of age with initial WBC count > or = 50,000/microL and/or age > or = 10 years. Randomly assigned therapies evaluated the impact of postinduction treatment intensification on outcome. We examined outcome and prognostic factors for 262 young adults with ALL. RESULTS Five-year event-free and overall survival rates for young adult patients are 71.5% (SE, 3.6%) and 77.5% (SE, 3.3%), respectively. Rapid responder patients (< 25% bone marrow blasts on day 7) randomly assigned to augmented therapy had 5-year event-free survival of 81.8% (SE, 7%), as compared with 66.8% (SE, 6.7%) for patients receiving standard therapy (P = .07). One versus two interim maintenance and delayed intensification courses had no significant impact on event-free survival. WBC count more than 50,000/microL was an adverse prognostic factor. CONCLUSION Young adult patients with ALL showing a rapid response to induction chemotherapy benefit from early intensive postinduction therapy but do not benefit from a second interim maintenance and delayed intensification phase. Given the excellent outcome with this chemotherapy, there seems to be no role for the routine use of allogeneic stem-cell transplantation in first remission for young adults with ALL.


The American Journal of Surgical Pathology | 2000

Metastatic Metanephric Adenoma in a Child

Andrew A. Renshaw; David R. Freyer; Yuki Hammers

Metanephric adenoma is a recently characterized renal tumor that generally occurs in adults and has an excellent prognosis. To date, only one atypical metanephric adenoma has been reported to metastasize. The authors report a case of typical metanephric adenoma that arose in the left kidney of a 7-year-old girl that was associated with metastases to the para-aortic, hilar, and aortic bifurcation lymph nodes. The tumor was 9.5 cm and was composed entirely of epithelial elements arranged in tubules, short papillae, and glomeruloid bodies with scattered psammoma bodies. No atypia and only rare mitotic activity were present. Immunohistochemically, the tumor was negative for epithelial membrane antigen, negative for keratin AE1, and focally positive for both keratin CAM5.2 and cytokeratin 7. Tumor cytogenetics revealed a normal diploid karyotype, and disomy of chromosomes 7 and 17 was confirmed by fluorescence in situ hybridization. The authors conclude that tumors with histologic, immunohistochemical, and genetic features characteristic of typical metanephric adenoma can present with metastatic disease.


Journal of Pediatric Hematology Oncology | 2008

The effect of cyproheptadine hydrochloride (Periactin®) and megestrol acetate (Megace®) on weight in children with cancer/treatment-related cachexia

Marisa Couluris; Jennifer L. R. Mayer; David R. Freyer; Eric Sandler; Ping Xu; Jeffrey P. Krischer

Background Children with cancer frequently have associated cachexia and malnutrition. Failure to thrive affects nearly 40% of oncology patients with advanced or progressive disease. Malnutrition can erode quality of life and adversely impact disease prognosis. Appetite stimulation and increased food intake is 1 approach to combat cancer-related cachexia. Materials and Methods Cyproheptadine hydrochloride (CH), an appetite stimulant, was administered to children with cancer-associated cachexia to prevent further weight loss. All participants started CH and were evaluated for response after 4 weeks. Efficacy of megestrol acetate (MA) was evaluated in patients who did not respond to CH. Medical evaluation, weight measurements, prealbumin, and serum leptin levels were preformed at follow-up visits. Results Seventy patients were enrolled. Of the 66 evaluable patients, 50 demonstrated a response to CH (average weight gain 2.6 kg and mean weight-for-age z-score change of 0.35, P=0.001). Seven of the 16 nonresponders received MA. Six patients completed 4 weeks of MA, 5 responded (average weight gain of 2.5 kg). The most commonly reported side effect of CH was drowsiness. One patient on MA developed low cortisol levels and hyperlipidemia. Conclusions This study demonstrates that CH is a safe and effective way to promote weight gain in children with cancer/treatment-related cachexia.


Cancer | 2013

Differences in outcomes of newly diagnosed acute myeloid leukemia for adolescent/young adult and younger patients: a report from the Children's Oncology Group.

Jason Canner; Todd A. Alonzo; David R. Freyer; Alan S. Gamis; Robert B. Gerbing; Beverly J. Lange; Soheil Meshinchi; William G. Woods; John P. Perentesis; John Horan

Studies comparing survival of adolescent and young adult (AYA) patients to that of younger patients with newly diagnosed acute myeloid leukemia (AML) have yielded conflicting results. In order to more accurately characterize relative survival and other outcomes of AYA patients, a cross‐study analysis was conducted using data from recent trials conducted by the Childrens Cancer Group (CCG) and Childrens Oncology Group (COG).

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Richard Sposto

University of Southern California

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Nita L. Seibel

National Institutes of Health

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Jemily Malvar

Children's Hospital Los Angeles

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Etan Orgel

Children's Hospital Los Angeles

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Ann S. Hamilton

University of Southern California

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Leo Mascarenhas

University of Southern California

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Girish Dhall

Children's Hospital Los Angeles

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Joel Milam

University of Southern California

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