Faculty Bibliography

Inflammatory orbital lesions include a broad list of diagnoses, many of them with overlapping clinical and radiographic features. They often present a diagnostic conundrum, even to the most experienced orbital specialist, thus placing considerable weight on surgical biopsy and histopathological analysis. However, histopathological diagnosis is also inherently challenging due to the rarity of these lesions and the overlaps in histologic appearance among distinct disease entities. We herein present the case of an adolescent male with a subacutely progressive orbital mass that generated a significant diagnostic dilemma. Early orbital biopsy was consistent with a benign fibro-inflammatory lesion, but corticosteroid therapy was ineffective in halting disease progression. After an initial substantial surgical debulking, histopathological analysis revealed several key features consistent with IgG4-related disease (IgG4-RD), a systemic fibro-inflammatory process typically accompanied by multifocal tumor-like lesions. Surprisingly, within months, there was clear evidence of clinical and radiographic disease progression despite second-line rituximab treatment, prompting a second surgical debulking. This final specimen displayed distinctive features of Rosai-Dorfman disease (RDD), a systemic inflammatory disease characterized by uncontrolled histiocytic proliferation. Interestingly, certain features of this re-excision specimen were still reminiscent of IgG4-RD, which not only reflects the difficulty in differentiating RDD from IgG4-RD in select cases, but also illustrates that these diagnoses may exist along a spectrum that likely reflects a common underlying pathogenetic mechanism. This case emphasizes the importance of surgical biopsy or resection and histopathological analysis in diagnosing-and, ultimately, treating-rare, systemic inflammatory diseases involving the orbit, and, furthermore, highlights the shared histopathological features between RDD and IgG4-RD.

Pleomorphic xanthoastrocytoma (PXA) is a rare type of brain tumor that affects children and young adults. Molecular prognostic markers of PXAs remain poorly established. Similar to gangliogliomas, PXAs show prominent immune cell infiltrate, but its composition also remains unknown. In this study, we correlated DNA methylation and BRAF status with clinical outcome and explored the tumor microenvironment. We performed DNA methylation in 21 tumor samples from 18 subjects with a histological diagnosis of PXA. MethylCIBERSORT was used to deconvolute the PXA microenvironment by analyzing the associated immune cell-types. Median age at diagnosis was 16 years (range 7-32). At median follow-up of 30 months, 3-year and 5-year overall survival was 73% and 71%, respectively. Overall survival ranged from 1 to 139 months. Eleven out of 18 subjects (61%) showed disease progression. Progression-free survival ranged from 1 to 89 months. Trisomy 7 and CDKN2A/B (p16) homozygous deletion did not show any association with overall survival (p = 0.67 and p = 0.74, respectively). Decreased overall survival was observed for subjects with tumors lacking the BRAF V600E mutation (p = 0.02). PXAs had significantly increased CD8 T-cell epigenetic signatures compared with previously profiled gangliogliomas (p = 0.0019). The characterization of immune cell-types in PXAs may have implications for future development of immunotherapy.

BACKGROUND:"Head Start" III, was a prospective clinical trial using intensive induction followed by myeloablative chemotherapy and autologous hematopoietic cell rescue (AuHCR) to either avoid or reduce the dose/volume of irradiation in young children with medulloblastoma. METHODS:Following surgery, patients received five cycles of induction followed by myeloablative chemotherapy using carboplatin, thiotepa, and etoposide with AuHCR. Irradiation was reserved for children >6 years old at diagnosis or with residual tumor post-induction. RESULTS:Between 2003 and 2009, 92 children <10 years old with medulloblastoma were enrolled. 5-year event-free survival (EFS) and overall-survival (OS) rates (±SE) were 46±5% and 62±5% for all patients, 61±8% and 77±7% for localized medulloblastoma, and 35±7% and 52±7% for disseminated patients. Nodular/desmoplastic (ND) medulloblastoma patients had 5-year EFS and OS (±SE) rates of 89±6% and 89±6% compared to 26±6% and 53±7% for classic and 38±13% and 46±14% for large-cell/anaplastic (LCA) medulloblastoma, respectively. In multivariate Cox regression analysis, histology was the only significant independent predictor of EFS after adjusting for stage, extent of resection, regimen, age and sex (p<0.0001). 5-year irradiation-free EFS was 78±8% for ND and 21±5% for classic/LCA medulloblastoma patients. Myelosuppression was the most common toxicity with two toxic deaths. Twenty-four survivors completed neurocognitive evaluation at a mean of 4.9 years post-diagnosis.IQ and memory scores were within average range overall whereas processing speed and adaptive functioning were low-average. CONCLUSION/CONCLUSIONS:We report excellent survival and preservation of mean IQ and memory for young children with ND medulloblastoma using high-dose chemotherapy with most patients surviving without irradiation.

BACKGROUND:We report the outcomes of patients with pineoblastoma and trilateral retinoblastoma syndrome enrolled on the Head Start (HS) I-III trials. METHODS:Twenty-three children were enrolled prospectively between 1991 and 2009. Treatment included maximal surgical resection followed by five cycles of intensive chemotherapy and consolidation with marrow-ablative chemotherapy and autologous hematopoietic cell rescue (HDCx/AuHCR). Irradiation following consolidation was reserved for children over six years of age or those with residual tumor at the end of induction. RESULTS:Median age was 3.12 years (range, 0.44-5.72). Three patients withdrew from the study treatment and two patients experienced chemotherapy-related death. Eight patients experienced progressive disease (PD) during induction chemotherapy and did not proceed to HDCx/AuHCR. Ten patients received HDCx/AuHCR; eight experienced PD post-consolidation. Seven patients received craniospinal irradiation (CSI) with a median dose of 20.7 Gy (range, 18-36 Gy) with boost(s) (median dose 27 Gy; range, 18-36 Gy); three received CSI as adjuvant therapy (two post-HDCx/AuHCR) and four upon progression/recurrence. The five-year progression-free survival (PFS) and overall survival (OS) were 9.7% (95% confidence intervals [CI]: 2.6%-36.0%) and 13% (95% CI: 4.5%-37.5%), respectively. Only three patients survived beyond five years. Favorable OS prognostic factors were CSI (hazard ratio [HR] = 0.30 [0.11-0.86], P = 0.025) and HDCx/AuHCR (HR = 0.40 [0.16-0.99], P = 0.047). CONCLUSIONS:Within the HS I-III trials, CSI and HDCx/AuHCR were statistically associated with improved survival. The high PD rate during later induction cycles and following consolidation chemotherapy warrants consideration of fewer induction cycles prior to consolidation and the potential intensification of consolidation with multiple cycles of marrow-ablative chemotherapy and irradiation.

PURPOSE/OBJECTIVE:Molecular subgroups of pediatric brain tumors associated with divergent biological, clinical, and prognostic features have been identified. However, data regarding the impact of subgroup affiliation on the outcome of children with malignant brain tumors treated with radiation-sparing protocol is limited. We report long-term clinical outcomes and the molecular subgroups of malignant brain tumors in young children whose first-line treatment was high-dose chemotherapy without irradiation. METHODS:Tumor subclassification was performed using the Illumina HumanMethylation450 BeadChip (450k) genome-wide methylation array profiling platform. Clinical information was obtained from chart review. RESULTS:Methylation array profiling yielded information on molecular subgroups in 22 children. Median age at surgery was 26 months (range 1-119 months). Among medulloblastomas (MB), all 6 children in the infant sonic hedgehog (SHH) subgroup were long-term survivors, whereas all 4 children in subgroup 3 MB died. There was one long-term survivor in subgroup 4 MB. One out of five children with ependymoma was a long-term survivor (RELPOS). Both children with primitive neuroectodermal tumors died. One child with ATRT TYR and one child with choroid plexus carcinoma were long-term survivors. CONCLUSIONS:The efficacy of high-dose chemotherapy radiation-sparing treatment appears to be confined to favorable molecular subgroups of pediatric brain tumors, such as infant SHH MB. Identification of molecular subgroups that benefit from radiation-sparing therapy will aid in the design of prospective, "precision medicine"-driven clinical trials.

BACKGROUND: The EMulate Therapeutics Halo system is an investigational non-sterile, non-invasive, non-thermal, non-ionizing, portable, home-use medical device that uses a specific, localized ultra-low radio frequency energy (ulRFER) cognate for the treatment of pediatric brain tumors.
METHOD(S): Sixteen patients with brain tumors consisting of diffuse midline glioma/diffuse intrinsic pontine glioma (DMG/DIPG, n=14), recurrent medulloblastoma (n=1), or anaplastic astrocytoma (n=1) - were treated with the Halo under FDA's single-patient compassionate use pathway, as protocol deviations in a glioblastoma trial, or under TGA's Special Access Scheme. Baseline information and on-treatment safety and exposure data were collected.
RESULT(S): Patients ranged in age from 4 to 28 years (median = 8 years) and were diagnosed 91 - 1399 days (median = 397 days) prior to treatment with the Halo system. Patients were treated for 2 - 52 weeks (median = 15 weeks), with 4 patients still alive (all with a diagnosis of DMG/DIPG), and 3 still on treatment (ranging 18 - 52 weeks). Two out of the 16 patients reported mild-moderate adverse events - one patient reported nausea, fatigue, and excessive sleepiness, and one patient reported vomiting. No device-related serious adverse events were reported. Other adverse events reported were generally associated with progressive disease. Unsolicited, anecdotal reports from some parents/caregivers noted improvements in mobility, speech, and visual acuity while on treatment.
CONCLUSION(S): The Halo system appears to be safe and feasible for the treatment of pediatric brain tumors. Given that therapy is delivered non-invasively and no device-related serious adverse events were reported, further prospective study of the investigational device is warranted

ONC201, the first bitopic DRD2 antagonist for clinical oncology, has shown efficacy in H3 K27M-mutant glioma. We performed an integrated preclinical and clinical analysis of ONC201 in thalamic H3 K27Mmutant glioma. ONC201 was effective in mouse intra-uterine electroporation (IUE)-generated H3 K27M-mutant gliomas, with an in vitro IC50 of 500 nM and 50% prolongation of median survival in vivo (p=0.02, n=14). Elevated DRD2 expression was found in the thalamus of non-malignant brain tissue, leading to the hypothesis that thalamic tumors may be a particularly ONC201-sensitive sub-group. We analyzed thalamic H3 K27Mmutant glioma patients treated with ONC201 as of the 05/22/2019 cutoff date, which included patients who had recurrent disease prior to initiating ONC201 (n=20; 15-73 years old) and post-radiation non-recurrent patients (n=11; 5-19 years old). As of 5/22/2019, 10 of 20 recurrent patients and 9 of 11 non-recurrent patients remain on-treatment. Median PFS has not been reached for either cohort: median follow-up of 2.2 months (range: 0.6-37.9) for recurrent patients and 10.6 months (range: 4.3-20.5) from diagnosis for non-recurrent patients. Best response so far by RANO includes 1 CR, 2 PR, 7 SD, 9 PD, 1 NE for recurrent patients and 1 PR, 7 SD, 3 PD for non-recurrent patients. Additionally, 3 recurrent (-66%, -47%, -34%) and 2 non-recurrent (-40%, -10%) patients experienced regressions but are not yet confirmed PRs. For recurrent patients, median onset of response is 3.5 months (range: 2.2-3.8) and median duration of response has not been reached with a median follow-up of 12.5 months (range: 8.1-32.8). Preliminary analyses demonstrated a strong correlation of cell-free tumor DNA in plasma and CSF with MRI response. In summary, ONC201 demonstrates promising clinical efficacy in thalamic H3 K27M-mutant glioma patients, regardless of age. Micro-environmental DRD2 expression may enhance the overall ONC201 response and extend its therapeutic utility beyond H3 K27M-mutant glioma

ONC201, the first clinical bitopic DRD2 antagonist for clinical oncology, is in multiple Phase II advanced cancer clinical trials. The recommended phase 2 dose (RP2D) of 625mg ONC201 Q1W has been established in adult patients as a biologically active dose. ONC201 efficacy has been shown in high-grade glioma preclinical models and durable responses with single agent ONC201 have been reported in adult recurrent H3 K27M-mutant glioma patients. These observations, along with the subsequently discovered increased susceptibility of H3 K27Mmutant gliomas to ONC201, we initiated a Phase I pediatric clinical trial of ONC201 scaled by body weight. This multi-center, open-label, dose-escalation and dose-expansion clinical trial (NCT03416530) was designed to determine the pediatric RP2D of ONC201 administered as an oral capsule in post-radiation H3 K27M-mutant glioma (Arm A) or newly diagnosed DIPG (Arm B) patients. Molecular evaluations include assessment of intratumoral concentrations of ONC201 in pediatric midline gliomas patients (Arm C) and the effects of ONC201 in H3 K27M DNA levels in circulating CSF (Arm D). The single agent safety of ONC201 administered as an oral Ora-Sweet solution was also evaluated (Arm E). Enrollment as of May 22, 2019: 21 evaluable patients in Arm A, 8 patients in Arm B, 2 patients in Arm C, 9 patients in Arm D, 6 patients in Arm E. Arm A has accrued with a median age of 8 (range: 3-18) years. As of May 22, 2019, patients have received a median of 18 (range: 3-54) doses without any dose-limiting toxicities. Pharmacokinetic profiles were comparable to those observed in adults (Cmax ~2.1ug/mL; AUC ~2.3hr*ug/mL; Tmax ~1.9hr; T1/2 ~8hr) and exposure was similar across body weights. Safety, PK, PD, molecular correlatives, and clinical outcomes will be reported

BACKGROUND:H3 K27M-mutant diffuse midline glioma is a fatal malignancy with no proven medical therapies. The entity predominantly occurs in children and young adults. ONC201 is a small molecule selective antagonist of dopamine receptor D2/3 (DRD2/3) with an exceptional safety profile. Following up on a durable response in the first H3 K27M-mutant diffuse midline glioma patient who received ONC201 (NCT02525692), an expanded access program was initiated. METHODS:Patients with H3 K27M-mutant gliomas who received at least prior radiation were eligible. Patients with leptomeningeal spread were excluded. All patients received open-label ONC201 orally once every week. Safety, radiographic assessments, and overall survival were regularly assessed at least every 8 weeks by investigators. As of August 2018, a total of 18 patients with H3 K27M-mutant diffuse midline glioma or DIPG were enrolled to single patient expanded access ONC201 protocols. Among the 18 patients: seven adult (> 20 years old) and seven pediatric (< 20 years old) patients initiated ONC201 with recurrent disease and four pediatric patients initiated ONC201 following radiation, but prior to disease recurrence. FINDINGS/RESULTS:Among the 14 patients with recurrent disease prior to initiation of ONC201, median progression-free survival is 14 weeks and median overall survival is 17 weeks. Three adults among the 14 recurrent patients remain on treatment progression-free with a median follow up of 49.6 (range 41-76.1) weeks. Among the 4 pediatric patients who initiated adjuvant ONC201 following radiation, two DIPG patients remain progression-free for at least 53 and 81 weeks. Radiographic regressions, including a complete response, were reported by investigators in a subset of patients with thalamic and pontine gliomas, along with improvements in disease-associated neurological symptoms. INTERPRETATION/CONCLUSIONS:The clinical outcomes and radiographic responses in these patients provide the preliminary, and initial clinical proof-of-concept for targeting H3 K27M-mutant diffuse midline glioma with ONC201, regardless of age or location, providing rationale for robust clinical testing of the agent.