Combined Immunotherapy Improves Outcome for Replication-Repair-Deficient (RRD) High-Grade Glioma Failing Anti-PD-1 Monotherapy: A Report from the International RRD Consortium.

Immune checkpoint inhibition (ICI) is effective for replication-repair-deficient, high-grade gliomas (RRD-HGG). The clinical/biological impact of immune-directed approaches after failing ICI monotherapy is unknown. We performed an international study on 75 patients treated with anti-PD-1; 20 are progression free (median follow-up, 3.7 years). After second progression/recurrence (n = 55), continuing ICI-based salvage prolonged survival to 11.6 months (n = 38; P < 0.001), particularly for those with extreme mutation burden (P = 0.03). Delayed, sustained responses were observed, associated with changes in mutational spectra and the immune microenvironment. Response to reirradiation was explained by an absence of deleterious postradiation indel signatures (ID8). CTLA4 expression increased over time, and subsequent CTLA4 inhibition resulted in response/stable disease in 75%. RAS-MAPK-pathway inhibition led to the reinvigoration of peripheral immune and radiologic responses. Local (flare) and systemic immune adverse events were frequent (biallelic mismatch-repair deficiency > Lynch syndrome). We provide a mechanistic rationale for the sustained benefit in RRD-HGG from immune-directed/synergistic salvage therapies. Future approaches need to be tailored to patient and tumor biology. SIGNIFICANCE: Hypermutant RRD-HGG are susceptible to checkpoint inhibitors beyond initial progression, leading to improved survival when reirradiation and synergistic immune/targeted agents are added. This is driven by their unique biological and immune properties, which evolve over time. Future research should focus on combinatorial regimens that increase patient survival while limiting immune toxicity. This article is featured in Selected Articles from This Issue, p. 201.

Measure Twice: Promise of Liquid Biopsy in Pediatric High-Grade Gliomas.

PURPOSE: To review and critique the current state of liquid biopsy in pHGG. MATERIALS AND METHODS: Published literature was reviewed for articles related to liquid biopsy in pediatric glioma and adult glioma with a focus on high-grade gliomas. RESULTS: This review discusses the current state of liquid biomarkers of pHGG and their potential applications for liquid biopsy development. CONCLUSIONS: While nascent, the progress toward identifying circulating analytes of pHGG primes the field of neuro-oncoogy for liquid biopsy development.

Delirium in the pediatric hematology, oncology, and bone marrow transplant population.

BACKGROUND: Delirium affects 10% to 30% of patients in pediatric intensive care units (PICU) and is associated with increased length of stay and prolonged late sequela. There are no prospective trials evaluating delirium in the pediatric hematology, oncology, and bone marrow transplant (PHO) population. Hypothesizing that delirium is underrecognized in this population, our study aimed to identify the prevalence of delirium in hospitalized PHO patients and associated risk factors. PROCEDURE: PHO and PICU nurses were trained to use the Cornell Assessment for Pediatric Delirium and to record scores once every 12-hour shift. Predetermined demographic and clinical variables were collected daily on all hospitalized PHO patients during the year-long prospective study. RESULTS: Prior to initiating routine delirium screening, 1.1% of PHO admissions and 2.4% of unique patients had delirium mentioned in a progress note. This study included 807 consecutive admissions: 671 oncology, 49 hematology, and 87 bone marrow transplant (BMT) hospitalizations among 223 unique PHO patients. The prevalence of delirium among hospitalizations was 5% and among unique patients was 13%. Among BMT hospitalizations, the prevalence was 23%. Multiple logistic regression identified significant association of delirium with increased length of stay, admission to the BMT service, patient location (PICU vs PHO unit), benzodiazepine, opioid, and anticholinergic administration. CONCLUSIONS: Before routine screening, delirium was underrecognized in this PHO-hospitalized population. Patients at highest risk had prolonged hospital stays, PICU admissions, BMT, and/or frequent use of benzodiazepines, opioids, or anticholinergics. Routine screening is feasible and may improve our recognition of delirium.