Reddy, Alyssa

Autoimmune diseases arise when B and T lymphocytes lose tolerance to self. Yet in most disorders, the underlying molecular determinants, including autoantibodies, epitopes and lymphocyte clones that drive tissue injury remain undefined. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD) is a rare and often fatal pediatric neuroendocrine syndrome with strong evidence of antigen-driven paraneoplastic autoimmunity, including association with the intracellular autoantigen ZSCAN1. However, the effector immune circuit and the epitope-level determinants operating within the hypothalamus and brainstem have remained unknown. To address this challenge in ROHHAD and more broadly in autoimmune disease, we developed the Autoimmune Epitope and immunoGlobulin/Immune-receptor identification System (AEGIS), an integrated framework that links immune repertoires to their cognate self-epitopes. AEGIS combines B cell and T cell receptor profiling from sites of tissue injury with high-resolution epitope mapping, direct sequencing of antigen-specific autoantibodies, in silico antibody-antigen folding, selection, and T cell antigen discovery. Applied to a deeply phenotyped child with ROHHAD, AEGIS revealed a compartmentalized, clonally restricted immune response in which brain-deposited IgG and expanded cerebrospinal fluid B cell and CD4 T cell clonotypes converged on shared ZSCAN1 epitopes, resolved to minimal determinants and peptide-MHC ligands. These findings provide a clone- and epitope-linked mechanistic map of ROHHAD autoimmunity and establish a generalizable framework for identifying candidate pathogenic clones and antigens across diverse autoimmune diseases.

Abstract Response Assessment in Pediatric Neuro-Oncology (RAPNO) is an international working group dedicated to developing standardized recommendations for response assessment in children with central nervous system tumors enrolled on clinical trials. This standardization facilitates easier and more reliable comparison of responses across trials. Since the first RAPNO publication in 2013, response guidelines have been issued for medulloblastoma (MB), low-grade glioma (LGG), high-grade glioma (HGG), diffuse intrinsic pontine glioma, ependymoma, and craniopharyngioma. Many of these guidelines have already been incorporated into clinical trials to evaluate their effectiveness and accuracy. RAPNO has always been predicated on the idea that these consensus recommendations will require updates over time as they are applied in practice given technological advancements, evolving treatment approaches, and growing knowledge of disease pathology. A half-day RAPNO symposium sponsored by the Society of Neuro-Oncology was held in San Diego, California, United States, on May 15, 2025. This event coincided with the 8th Biennial Pediatric Society of Neuro-Oncology meeting. The main objectives were to identify ongoing RAPNO challenges, discuss potential updates, and plan future initiatives across 3 specific groups: (1) LGG/Craniopharyngioma, (2) HGG/diffuse midline glioma (DMG)/Ependymoma, and (3) MB and other seeding tumors. This manuscript reviews the symposium proceedings and highlights key topics and challenges discussed, as well as outlining future RAPNO initiatives.

Abstract Background Children’s Oncology Group ACNS0333 treated atypical teratoid/rhabdoid tumor (ATRT) with surgery, chemotherapy (induction and consolidation) and radiation therapy (RT). M0 had focal RT and M+ had physician-selected focal RT or craniospinal (CSI). Methods Forty patients (29 M0, 11 M+) received RT. Pre-RT chemotherapy response was complete, partial, or stable disease. RT timing (age/stage-based) was pre-consolidation (RT-first) or post-consolidation (consolidation-first). Event-free survival (RT-EFS), overall survival (RT-OS), and cumulative incidence of local relapse (CILR) or distant relapse (RT-CIDR) were calculated. Analyses included log-rank tests and relative hazard rates with 95% confidence intervals to estimate proportional hazards regression. Results Four-year RT-EFS was 56.8% and 4-year RT-OS was 58.8% focal RT: 34 patients, CSI: 6 patients). A trend for superior RT-EFS for M+ compared to M0 (P = .0625, RHR 0.26; 95% CI 0.06-1.18) was shown. RT-EFS was improved for consolidation-first compared to RT-first timing (P = .037, RHR 0.43; 95% CI 0.13-1.37). Pre-RT chemotherapy response was associated with improved RT-EFS (P = .031) and RT-OS (P = .0069). Four-year RT-CILR was 7.84%; no differences in RT-CILR were shown for higher primary RT dose (≥5400 cGy, P = .38) or gross total resection (P = .80). 4-year RT-CIDR was 27.8% for M0 and 9.1% for M+ patients (P = .22). M+ had CSI (n = 6) or focal RT (n = 5). Fatal necrosis potentially-attributable to RT occurred in 3 RT-first patients (occuring either 1.6, 4.6, or 16.2 months post-treatment). Conclusions RT with intensive systemic therapy showed promising survival outcomes and effective primary disease control in ATRT. Sequencing RT prior to myeloblative chemotherapy, rather than post-consolidation, may be associated with increased risk of fatal radionecrosis.

Abstract Introduction: Cystic fibrosis (CF) is a genetic disorder characterized by defective chloride ion transport, leading to thick mucus production, chronic respiratory infections, and other multisystem involvement. Although CF is often diagnosed in childhood, the condition can be missed or misdiagnosed in adults. Description of Case: We present the case of a 60-year-old male from India who was diagnosed with CF after a prolonged period of sinopulmonary symptoms. He initially presented in 2014. His medical history was pertinent for asthma, and multiple episodes of clinically and radiographically confirmed pneumonia and polypoid sinusitis requiring IV antibiotics and sinus surgery. He carried a prior diagnosis of allergic bronchopulmonary aspergillosis treated with itraconazole and steroids, as well as elevated IgE levels. His CT chest was notable for extensive bronchiectasis, bronchial wall thickening, and mucus plugging of both lungs. He had no known family history of CF. Sweat chloride testing was in the intermediate range (44, 47 mmol/L; normal <30 mmol/L, intermediate 30 to 59 mmol/L, abnormal >59 mmol/L). Given high suspicion for CF, cystic fibrosis transmembrane conductance regulator (CFTR) full gene analysis was pursued. Sequence analysis and multiplex ligation-dependent probe amplification of the CFTR gene detected heterozygous sequence changes c.1717-2A>T, classified as likely deleterious, and c.1367T>C (p.V456A), variant of uncertain significance. He was thus initially diagnosed as a CF carrier. He re-presented in 2024 with decline in pulmonary function testing and continued sinopulmonary infections. Genetic testing results from 2014 were re-analyzed. Between initial presentation and present, his V456A variant was upgraded to pathogenic. He met diagnostic criteria for CF with two pathogenic CFTR variants, a repeated intermediate sweat chloride (47 mmol/L) suggestive of CFTR protein dysfunction, and disease that could be attributed to CFTR dysfunction. He subsequently started TRIKAFTA® (elexacaftor/tezacaftor/ivacaftor and ivacaftor) and airway clearance therapy. Discussion: The diagnosis of CF in adults can be challenging, particularly in individuals without a known family history, intermediate sweat chloride testing, and with inconclusive genetic testing. Our understanding of CF in Asian populations is limited. CF is suspected to be underreported in patients with Southeast Asian ancestry in part due to genetic heterogeneity. The interpretation of certain genetic variants can evolve over time. A variant of unknown significance may later be reclassified as pathogenic, revealing its true role in disease development. This highlights the critical importance of regularly re-evaluating genetic test results.

ABSTRACT Background Nab ‐sirolimus (ABI‐009, nab ‐rapamycin; Aadi Bioscience Inc. [Aadi]) is a human albumin‐bound form of sirolimus nanoparticles, a potent mTOR inhibitor. This phase I trial was conducted to define dose‐limiting toxicities (DLT), maximum tolerated or recommended phase II dose (MTD/RP2D), and pharmacokinetics of Nab ‐sirolimus in combination with temozolomide and irinotecan. Methods Using a rolling 6 design, Nab ‐sirolimus was administered intravenously (IV) on days (D) 1 and 8 of cycle (C) 1. In subsequent cycles, Nab ‐sirolimus was administered D1 and D8 in combination with temozolomide (125 mg/m 2 /dose, maximum 250 mg/dose) and irinotecan (90 mg/m 2 /dose) orally, daily on D1–5. Cycle duration was 21 days. Three dose levels (DL) of Nab ‐sirolimus were investigated (DL1: 35 mg/m 2 /dose, DL‐1: 20 mg/m 2 /dose, and DL‐2: 15 mg/m 2 /dose). The observation period for estimating the MTD/RP2D was defined by cycles 1 and 2. Results Thirty‐three patients were enrolled, 32 were eligible. Dose determination included 17 evaluable patients, median (range) age 12 (2–20) years and six additional patients were enrolled (four evaluable for toxicity) on a pharmacokinetic cohort. C1 or C2 DLTs were primarily thrombocytopenia including 2/5 patients at DL1, 2/6 patients at DL‐1, and 1/6 patients at DL‐2. One patient (DL1) with Ewing Sarcoma had a partial response and remained on study for 35 cycles. Rapamycin clearance was dose dependent. Irinotecan clearance and its active metabolite SN‐38 exposure were not affected by coadministration with Nab ‐sirolimus. Conclusion The MTD for Nab ‐sirolimus was 15 mg/m 2 /dose IV on D1 and D8 in combination with temozolomide 125 mg/m 2 /dose and oral irinotecan 90 mg/m 2 /dose daily for 5 days during 21D cycles. Trial Registration ClinicalTrials.gov identifier NCT02975882

Abstract BACKGROUND Treatment and clinical management decisions for children with NF1-OPGs remain challenging as most existing data are retrospective and have not included standardized visual outcomes. In this study, we prospectively enrolled newly diagnosed NF1-OPGs and performed standardized neuro-oncology and ophthalmology assessments in order to develop evidence-based guidelines for monitoring and treatment. METHODS Children with NF1-OPG on MRI who were evaluated by both a study ophthalmologist and neuro-oncologist/NF1 expert within 1 month of radiologic diagnosis were eligible for enrollment. All subjects attempted quantitative visual acuity using Teller acuity cards (TAC) as well as ATS-HOTV testing. The neuro-oncologist/NF1 expert provided reasons for obtaining the MRI as well as initiating treatment, if applicable. Descriptive statistics calculated the success rate of acquiring TAC and reasons to obtain the MRI. RESULTS Two-hundred fifty subjects from 22 institutions were enrolled and had at least one visit beyond baseline (Median age 3.1 years, range 0.1–16.8; 53% female). TAC was successfully acquired in both eyes (N=195, 78%) and at least one eye in (N=206, 82%). ATS-HOTV was successfully acquired in both eyes (N=97, 39%) and at least one eye in (N=98, 39%). The two most common reasons to obtain an MRI were screening due to a diagnosis of NF1 (N=99, 39%) and ophthalmologic concern (N=81, 32%). At enrollment, continued observation occurred in a majority of subjects (N=221, 88%) while treatment with chemotherapy was initiated in only 11% (N=29). Twenty-nine (11%) subjects initially observed transitioned to treatment after enrollment (range: 2.5–25 months) thus far. DISCUSSION We present a prospective multicenter study of children with newly diagnosed NF1-OPGs. The ability to acquire quantitative visual acuity was higher than anticipated. The frequency of NF1-OPGs requiring treatment is lower than previously reported. Regression models of clinical and MRI features that prompted immediate treatment with chemotherapy versus observation will be discussed.

Abstract BACKGROUND NF1-OPGs are amorphous tumors involving either single or multiple locations (optic nerve, chiasm, tract) along the anterior visual pathway (AVP). In this prospective study, we investigated how volumetric MRI measures of the AVP as well as other clinical variables are associated with treatment decisions in children with newly diagnosed NF1-OPGs. METHODS Children with newly diagnosed NF1-OPG whose MRI included a T1-weighted volumetric sequence without significant artifact at their enrollment visit were eligible for inclusion. All subjects underwent a quantitative ophthalmic exam to determine if visual acuity (VA) was normal. The neuro-oncologist/NF1 expert determined whether the subject would be observed or undergo treatment at that baseline visit. Volumetric MRI analysis was automatically performed using a deep learning network that measured AVP volume (mm3). Non-parametric group comparisons and multivariable logistic regression models evaluated the impact of age at enrollment, sex, NF1 inheritance type, AVP volume, and VA on the decision for immediate treatment with chemotherapy versus observation. RESULTS One-hundred twenty-three subjects met inclusion criteria. Subjects assigned to observation (N=112, 44% female) and subjects immediately treated with chemotherapy (N=11, 80% female) at enrollment were of similar age (2.7 and 2.8 years, respectively) and inheritance (p > 0.05). Abnormal VA was present more often in the treatment group (46%) compared to the observation group (17%, p <0.001). AVP volume was significantly greater in the treatment group (4,181.1mm3) compared to the observation group (1,819.8mm3, p <0.001). AVP volume, sex, and VA reached significance in univariable regression, however, in the multivariable regression model only the AVP volume (p < 0.001) was significantly associated with treatment initiation. DISCUSSION Children with greater NF1-OPG AVP volumes are treated more often compared with those with lower volumes. Volumetric measures of NF1-OPGs are a valuable metric in understanding treatment patterns and are positioned to help inform clinical decision making.

AbstractPurposeRadiotherapy (RT) is associated with improved survival in atypical teratoid/rhabdoid tumor (ATRT); however, optimal RT delivery is unknown. A meta‐analysis was conducted for disseminated (M+) ATRT receiving focal or craniospinal radiation (CSI).MethodsAfter abstract screening, 25 studies (1995–2020) contained necessary patient, disease, and radiation treatment information (N = 96). All abstract, full text, and data capture were independently double‐reviewed. The corresponding author was contacted for cases of insufficient information. Response to pre‐radiation chemotherapy (N = 57) was categorized as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). Univariate and multivariate statistics were performed to investigate survival correlation. Patients with M4 disease were excluded.ResultsThe 2‐ and 4‐year overall survival (OS) was 63.8% and 45.7%, respectively, with a median follow‐up of 2 years (range 0.3–13.5). The median age was 2 years (range 0.2–19.5), and 96% received chemotherapy. On univariate analysis, gross total resection (GTR, p = .0007), pre‐radiation chemotherapy response (p < .001), and high‐dose chemotherapy with stem cell recuse (HDSCT, p = .002) correlated with survival. On multivariate analysis, pre‐radiation chemotherapy response (p = .02) and GTR (p = .012) retained survival significance as compared to a trend for HDSCT (p = .072). Comparisons of focal RT (vs. CSI) and greater than or equal to 5400 cGy primary dose were nonsignificant. Following CR or PR, a statistical trend favored focal radiation (p = .089) over CSI.ConclusionChemotherapy response prior to RT and GTR correlated with improved survival on multivariate analysis for ATRT M+ receiving RT. No benefit was observed for CSI compared to focal RT among all patients and following favorable chemotherapy response, inviting further study of focal RT for ATRT M+.

10022 Background: nab-Sirolimus (formerly know ABI-009 and nab-rapamycin) is a novel human albumin-bound preparation of sirolimus, a potent mTOR inhibitor. We report results of a Phase I study of ABI-009 alone and in combination with irinotecan and temozolomide in children with relapsed/refractory solid or CNS tumors. Methods: Patients (age 1-21 years) with relapsed/refractory solid or CNS tumors were eligible. Using a rolling 6 design, ABI-009 was administered intravenously as a single agent on Days 1 and 8 of cycle 1 (cycle = 21d), then subsequent cycles ABI-009 was administered in combination with temozolomide (125 mg/m2/dose, maximum 250 mg/dose) orally once daily x 5 on Days 1-5 and irinotecan 90 mg/m2/dose orally once daily x 5 on Days 1-5. Three dose levels (DL) of ABI-009 were investigated (DL1: 35mg/m2/dose, DL-1: 20mg/m2/dose, and DL-2: 15mg/m2/dose). The maximum tolerated dose (MTD) or Recommended Phase 2 Dose (RP2D) was established based on dose limiting toxicity (DLT) observed during Cycle 1 and 2. At the RP2D, additional patients were enrolled for pharmacokinetics (PK). Results: 33 patients were enrolled (32 eligible and 1 ineligible); 11 did not experience DLT but were not evaluable for toxicity due to progressive disease or physician decision to discontinue protocol therapy prior to completion of cycle 2; 17 [median age 13 (2-20) years] were evaluable for determination of MTD during dose escalation, 6 were enrolled on the PK cohort, of which 3 were evaluable to toxicity. At DL1, 2/5 patients experienced DLT (thrombocytopenia during cycle 1 (n = 1) and cycle 2 (n = 1)); at DL-1, 2/6 patients experienced DLT (thrombocytopenia in cycle 1); at DL-2, 1/6 patients experienced DLT (thrombocytopenia in cycle 1). PK expansion enrolled at DL-2 and 1/3 participants evaluable for toxicity had a DLT (mucositis). Overall, at DL-2, 2/9 patients (22%) had DLT. One patient with Ewing Sarcoma had a partial response and remained on study for 35 cycles; Patients (one each) with Ewing Sarcoma, Wilms Tumor, and Pineoblastoma had stable disease, ranging from 3-6 cycles. Conclusions: Thrombocytopenia was dose limiting for ABI-009 alone and in combination with temozolomide and irinotecan. The MTD for ABI-009 is 15mg/m2/dose days 1 and 8 in combination with 5 daily doses of temozolomide 125 mg/m2/dose and oral irinotecan 90 mg/m2/dose. One patient had a partial response, 3 patients had prolonged stable disease. Pharmacokinetics and pharmacodynamics are pending and will inform future trials. Clinical trial information: NCT02975882.

Abstract Purpose Intensive multi-modal regimens have improved survival for patients with atypical teratoid rhabdoid tumor, however relapse rates remain high. A better understanding of clinical and pathologic features associated with tumor relapse is critical to risk-stratifying patients. Patients and Methods ACNS0333 treatment consisted of multi-agent chemotherapy, high-dose chemotherapy, and radiation therapy, lasting approximately 6 months. Variables including patient age, sex, tumor location, M-stage, degree of resection, order of therapy, germline status, and molecular subgroup were analyzed. Cumulative incidence (CI) of event free survival due to relapse was evaluated for each variable. Results Thirty-three of 65 evaluable patients had tumor relapse. For the entire cohort, the CI of relapse was 21.8% at 6 months, 40.6% at one year and 50.3% at 4 years. For patients with infratentorial tumors, CI of relapse was 26.3%, 34.2% and 37.2%, at 6 months, 1 and 4 years respectfully compared to 15.3%, 49.9%, and 69.7% for those with supratentorial tumors (p 0.051). Patients with SHH subtype had no relapses in the first 6 months and CI of relapse of 37.5% at 4 years, while those with TYR and MYC subgroups had CI of relapse of 33.3% and 26.7% at 6 months and 46.3% and 73.3% at 4 years respectfully (p 0.088). Patients with germline mutations had a cumulative incidence of relapse of 20% at 6 months and 60% at 12 months compared to 22.6% and 37.7% respectfully for those without. No obvious trends were noted based on other analyzed variables. Conclusions ACNS0333 was not powered to determine prognostic indicators of relapse, however, this data suggest interesting trends based on tumor location, subtype and germline status. Infratentorial location and SHH subtype maybe associated with lower risk of relapse. Larger data sets must be compiled to further investigate these variables, perform multivariate analyses and inform risk-stratification on future trials.