Variation of Diagnostic Approaches and Treatment Practices for Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome Among Pediatric Subspecialists.

OBJECTIVE: To assess the diagnostic and treatment practices among a variety of subspecialists at pediatric institutions in the US. STUDY DESIGN: Using a web-based survey, we assessed the consultation, diagnostic, and treatment preferences of providers from the different pediatric subspecialties who care for pediatric patients with hemophagocytic lymphohistiocytosis (HLH)/macrophage activating syndrome (MAS). Domains included demographics, provider training level and specialty, experience and comfort level with the diagnosis and treatment of HLH/MAS, and institutional approaches toward the diagnosis and management of HLH/MAS. Participants also were given 2 case scenarios: one describing Epstein-Barr virus-associated HLH and another describing an underlying rheumatologic condition with MAS. RESULTS: Of 263 respondents, 23%, 29%, 39%, and 7% identified as hematology/oncology, rheumatology, general pediatrics/critical care/hospitalist, and allergy/immunology, respectively. For Epstein-Barr virus/HLH, hematology/oncology was the preferred first consultant by most respondents other than rheumatologists, of whom only 47% agreed. For MAS, 92% of respondents from all specialties favored a rheumatology consultation. Preferred diagnostic tests varied by subspecialty, with hematology/oncology more likely than rheumatology to order an infectious workup, natural killer cell function, soluble interleukin-2 receptor, bone marrow biopsy, and genetic testing. First-line therapy also varied, with hematology/oncology preferring dexamethasone and etoposide and rheumatology more often preferring methylprednisolone and anakinra. One-half of respondents were unaware of institutional algorithms for diagnosis and treatment of HLH/MAS. Most (85.6%) favored the development of treatment algorithms for HLH/MAS, and 90% supported a multidisciplinary approach. CONCLUSIONS: Current consulting patterns, diagnostic workup, and treatment approaches of HLH/MAS vary by specialty, highlighting the need for standardized management algorithms and institutional multidisciplinary HLH/MAS teams.

Clinical Utility of Pegaspargase in Children, Adolescents and Young Adult Patients with Acute Lymphoblastic Leukemia: A Review.

Acute lymphoblastic leukemia (ALL) is a heterogenous hematological malignancy representing 25% of all cancers in children less than 15 years of age. Significant improvements in survival and cure rates have been made over the past four decades in pediatric ALL treatment. Asparaginases, derived from Escherichia coli and Erwinia chrysanthemi, have become a critical component of ALL therapy since the 1960s. Asparaginases cause depletion of serum asparagine, leading to deprivation of this critical amino acid for protein synthesis, and hence limit survival of lymphoblasts. Pegaspargase, a conjugate of monomethoxypolyethylene glycol (mPEG) and L-asparaginase, has become an integral component of pediatric upfront and relapsed ALL protocols due to its longer half-life and improved immunogenicity profile compared to native asparaginase preparations. Over the past two decades great strides have been made in outcomes for pediatric ALL due to risk stratification, incorporation of multiagent chemotherapy protocols, and central nervous system prophylaxis with pegaspargase having played an important role in this success. However, adolescents and young adults (AYA) with ALL when treated on contemporaneous trials using adult ALL regimens, continue to have poor outcomes. There is increasing realization of adapting pediatric trial regimens for treating AYAs, especially those incorporating higher intensity of chemotherapeutic agents with pegaspargase being one such agent. Dose or treatment-limiting toxicity is observed in 25-30% of patients, most notable being hypersensitivity reactions. Other toxicities include asparaginase-associated pancreatitis, thrombosis, liver dysfunction, osteonecrosis, and dyslipidemia. Discontinuation or subtherapeutic levels of asparaginase are associated with inferior disease-free survival leading to higher risk of relapse, and in cases of relapse, a higher risk for remission failure. This article provides an overview of available evidence for use of pegaspargase in pediatric acute lymphoblastic leukemia.

Adjuvant Maintenance Larotrectinib Therapy in 2 Children With NTRK Fusion-positive High-grade Cancers.

Treatment-related morbidity drives research to identify targetable lesions in children with cancer. Neurotrophic tropomyosin receptor kinase (NTRK) alterations occur in ~1% of pediatric solid tumors. Early phase pediatric trials involving the NTRK inhibitor treatment for progressive NTRK-mutated cancers show promising results. The authors describe the adjuvant maintenance larotrectinib treatment after definitive surgical resection in 2 toddlers with NTRK fusion-positive malignancies (ETV6-NTRK3 fusion-positive undifferentiated embryonal sarcoma of the kidney and NACC2-NTRK2 fusion-positive anaplastic astrocytoma). Both are alive, in remission, developing normally and tolerating larotrectinib 15 months later, thus extending the NTRK inhibitor therapeutic spectrum by describing the adjuvant maintenance larotrectinib treatment in children with NTRK fusion-positive cancers associated with high recurrences.