Locoregional CAR T Cells for the Treatment of CNS Tumors in Children: Investigational Drug Service Pharmacy Activities.

BACKGROUND: A major obstacle in translating the therapeutic potential of chimeric antigen receptor (CAR) T cells to children with central nervous system (CNS) tumors is the blood-brain barrier. To overcome this limitation, preclinical and clinical studies have supported the use of repeated, locoregional intracranial CAR T-cell delivery. However, there is limited literature available describing the process for the involvement of an investigational drug service (IDS) pharmacy, particularly in the setting of a children's hospital with outpatient dosing for CNS tumors. OBJECTIVES: To describe Seattle Children's Hospital's experience in clinically producing CAR T cells and the implementation of IDS pharmacy practices used to deliver more than 300 intracranial CAR T-cell doses to children, as well as to share how we refined the processing techniques from CAR T-cell generation to the thawing of fractionated doses for intracranial delivery. METHODS: Autologous CD4+ and CD8+ T cells were collected and transduced to express HER2, EGFR, or B7-H3-specific CAR T cells. Cryopreserved CAR T cells were thawed by the IDS pharmacy before intracranial delivery to patients with recurrent/refractory CNS tumors or with diffuse intrinsic pontine glioma/diffuse midline glioma. RESULTS: The use of a thaw-and-dilute procedure for cryopreserved individual CAR T-cell doses provides reliable viability and is more efficient than typical thaw-and-wash protocols. Cell viability with the thaw-and-dilute protocol was approximately 75% and was always within 10% of the viability assessed at cryopreservation. Cell viability was preserved through 6 hours after thawing, which exceeded the 1-hour time frame from thawing to infusion. CONCLUSION: As the field of adoptive immunotherapy grows and continues to bring hope to patients with fatal CNS malignancies, it is critical to focus on improving the preparatory steps for CAR T-cell delivery.

CAR T cell therapy for pediatric central nervous system tumors: a review of the literature and current North American trials.

Central nervous system (CNS) tumors are the leading cause of cancer-related death in children. Typical therapy for CNS tumors in children involves a combination of surgery, radiation, and chemotherapy. While upfront therapy is effective for many high-grade tumors, therapy at the time of relapse remains limited. Furthermore, for diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG), there are currently no curative therapies. Chimeric antigen receptor T (CAR T) cell therapy is a promising novel treatment avenue for these tumors. Here, we review the preclinical evidence for CAR T cell use in pediatric brain tumors, the preliminary clinical experience of CNS CAR T cell trials, toxicity associated with systemic and locoregional CAR T cell therapy for CNS tumors, challenges in disease response evaluation with CAR T cell therapy, and the knowledge gained from correlative biologic studies from these trials in the pediatric and young adult population.

Improving Time to Antibiotic Administration for Pediatric Oncology Patients With New-Onset Fever.

PURPOSE: Time to antibiotic administration (TTA) in <60 minutes for children with neutropenic fever presenting to an emergency room is associated with reduced incidence of sepsis and intensive care admission. As such, TTA is used as a national quality metric for pediatric oncology patients. At our center, in 2020, 19% of the hospitalized patients with a new fever encounter were receiving antibiotics in <60 minutes, prompting a multidisciplinary approach to reach a goal of >90% in all pediatric patients with cancer with a new fever. METHODS: A multidisciplinary team completed four Plan-Do-Study-Act cycles between March 2021 and September 2023. We implemented education initiatives, an updated handoff smartphrase guiding the on-call team, an antibiotic champion (AC) nursing role, a revised fever plan for handoff, a rapid-response team to address new fevers, and an algorithm for blood culture collection. Data were collected, analyzed, and reported biweekly with feedback sought for delays in TTA. RESULTS: There was a total of 639 new fevers in 329 unique oncology patients. As of September 4, 2023, average TTA decreased from 89 minutes at baseline to 46.4 minutes for more than 12 months. The percentage of patients receiving first dose of antibiotic in <60 minutes also increased from 19% to 93.7%, which was sustained as well. The most effective interventions were creation of the AC role and streamlining the blood culture collection process. CONCLUSION: This project demonstrates the importance of multidisciplinary involvement for providing optimal care. Specific implementation of targeted education, an AC role, and development of an algorithm streamlining the processes led to meaningful targeted improvements. Further analyses will explore the impact of these interventions on patient outcomes.

Locoregional CAR T cells for children with CNS tumors: Clinical procedure and catheter safety.

Central nervous system (CNS) tumors are the most common solid malignancy in the pediatric population. Based on adoptive cellular therapy's clinical success against childhood leukemia and the preclinical efficacy against pediatric CNS tumors, chimeric antigen receptor (CAR) T cells offer hope of improving outcomes for recurrent tumors and universally fatal diseases such as diffuse intrinsic pontine glioma (DIPG). However, a major obstacle for tumors of the brain and spine is ineffective T cell chemotaxis to disease sites. Locoregional CAR T cell delivery via infusion through an intracranial catheter is currently under study in multiple early phase clinical trials. Here, we describe the Seattle Children's single-institution experience including the multidisciplinary process for the preparation of successful, repetitive intracranial T cell infusion for children and the catheter-related safety of our 307 intracranial CAR T cell doses.

Progression-Free Survival and Patterns of Response in Patients With Relapsed High-Risk Neuroblastoma Treated With Irinotecan/Temozolomide/Dinutuximab/Granulocyte-Macrophage Colony-Stimulating Factor.

PURPOSE: Although chemoimmunotherapy is widely used for treatment of children with relapsed high-risk neuroblastoma (HRNB), little is known about timing, duration, and evolution of response after irinotecan/temozolomide/dinutuximab/granulocyte-macrophage colony-stimulating factor (I/T/DIN/GM-CSF) therapy. PATIENTS AND METHODS: Patients eligible for this retrospective study were age < 30 years at diagnosis of HRNB and received ≥ 1 cycle of I/T/DIN/GM-CSF for relapsed or progressive disease. Patients with primary refractory disease who progressed through induction were excluded. Responses were evaluated using the International Neuroblastoma Response Criteria. RESULTS: One hundred forty-six patients were included. Tumors were MYCN-amplified in 50 of 134 (37%). Seventy-one patients (49%) had an objective response to I/T/DIN/GM-CSF (objective response; 29% complete response, 14% partial response [PR], 5% minor response [MR], 21% stable disease [SD], and 30% progressive disease). Of patients with SD or better at first post-I/T/DIN/GM-CSF disease evaluation, 22% had an improved response per International Neuroblastoma Response Criteria on subsequent evaluation (13% of patients with initial SD, 33% with MR, and 41% with PR). Patients received a median of 4.5 (range, 1-31) cycles. The median progression-free survival (PFS) was 13.1 months, and the 1-year PFS and 2-year PFS were 50% and 28%, respectively. The median duration of response was 15.9 months; the median PFS off all anticancer therapy was 10.4 months after discontinuation of I/T/DIN/GM-CSF. CONCLUSION: Approximately half of patients receiving I/T/DIN/GM-CSF for relapsed HRNB had objective responses. Patients with initial SD were unlikely to have an objective response, but > 1 of 3 patients with MR/PR on first evaluation ultimately had complete response. I/T/DIN/GM-CSF was associated with extended PFS in responders both during and after discontinuation of treatment. This study establishes a new comparator for response and survival in patients with relapsed HRNB.

Treatment of central giant cell granuloma in children with denosumab.

Central giant cell granuloma (CGCG) is a benign but locally aggressive intraosseous lesion of the mandible. Historically, it is treated by curettage or resection. Medical therapy is indicated when surgery is associated with increased morbidity or in adjuvant setting to decrease recurrence. Treatment of CGCG with denosumab, a receptor activator of nuclear factor kappa-beta (RANK) ligand inhibitor, is not well studied, especially in children. Here, we describe our experience with the use of denosumab in the treatment of six children with CGCG. All patients had a favorable response with manageable side effects, which suggests that denosumab is an effective treatment option without increased morbidity.

Rapid development of anterotibial compartment syndrome and rhabdomyolysis in a patient with primary hypothyroidism and adrenal insufficiency.

BACKGROUND: Anterior compartment syndrome (ACS) and rhabdomyolysis are rare complications of hypothyroid myopathy. We report the case of a young man with rapid onset of ACS who presented with simultaneous primary hypothyroidism and adrenal insufficiency associated with acute renal failure, hyponatremia, and hyperkalemia. PATIENT FINDINGS: A 22-year-old man presenting with a one-month history of tiredness, hyperpigmentation, and cramps in his calves was found to have severe bilateral foot drop. Investigations revealed severe primary hypothyroidism and adrenal insufficiency, renal failure, and evidence of rhabdomyolysis with myoglobinuria. Abnormal biochemical findings included serum sodium of 110 mM, serum potassium of 6.9 mM, and serum creatine kinase (CK) of >25,000 IU/L. Magnetic resonance imaging (MRI) of his legs showed changes of myonecrosis confined to anterior tibial muscles typical of ACS. After treatment with intravenous fluids, potassium-lowering therapies, thyroxine, and hydrocortisone, his renal and metabolic function returned to normal, but irreversible bilateral foot drop persisted. SUMMARY: A young man with primary hypothyroidism, adrenal insufficiency, hyponatremia, and hyperkalemia presented with severe myopathy, such that muscle necrosis, apparently confined to the anterior tibial compartment on MRI, led to rhabdomyolysis, acute renal failure, and irreversible bilateral peroneal nerve damage. It is possible that other patients with primary hypothyroidism and marked elevations of CK without widespread myopathy or rhabdomyolysis may demonstrate evidence of differential muscle effects in the anterior compartment when assessed by MRI, but that this patient also had adrenal insufficiency raises the possibility that this was a contributing factor. CONCLUSIONS: Severe thyroid myopathy and rhabdomyolysis may be associated with anatomic susceptibility to ACS, particularly in the presence of concomitant adrenal insufficiency. MRI examination reveals a distinctive appearance of myonecrosis confined to the anterior compartment.