Chad Jacobsen

BACKGROUND: High-dose chemotherapy with autologous stem cell rescue (HDC/SCR) has produced responses and prolonged survival for some children with recurrent brain tumors, but is associated with considerable morbidity and mortality. A Phase I trial of two cycles of HDC/SCR for recurrent brain tumors in children was performed to determine the maximum tolerated doses for a novel regimen. PROCEDURES: Two cycles of HDC/SCR were given. Cycle 1 included thiotepa and carmustine given on days -5, -4, and -3. Four to six weeks later, patients received cycle 2 which included thiotepa and carboplatin given on days -5, -4, and -3. Autologous peripheral blood stem cells (PBSC) were infused on day 0 of each cycle. RESULTS: Thirty-two patients were treated and 25 patients received both cycles of HDC/SCR. Common toxicities included mucositis, emesis, diarrhea, anorexia, and pancytopenia. Eight of 32 (25%) assessable children died from regimen-related toxicity. Pulmonary failure occurred in seven patients. Seven patients had grade 3-4 neurotoxicity. The 3-year event-free survival (EFS) was 25%. CONCLUSIONS: We determined the maximum tolerated regimen to be thiotepa 600 mg/m(2) and carmustine 300 mg/m(2) followed by thiotepa 600 mg/m(2) and carboplatin 1,200 mg/m(2) . Pulmonary toxicity was considerable. The toxic death rate was similar to other trials of HDC/SCR for children with recurrent brain tumors performed during the same time period. The regimen resulted in prolonged time to progression for a significant number of patients and long-term survival for some patients with recurrent medulloblastoma and rhabdoid tumor.

TPS10561 Background: Aurora kinase A (AurA) has been implicated in high-risk neuroblastoma, including roles stabilizing and increasing expression of MYCN protein. AurA impacts the function of MYCN in mediating transcription in a cell cycle dependent manner, suggesting that neuroblastoma and other MYC/MYCN-driven tumors may be sensitive to AurA inhibition. LY3295668 is a selective AurA inhibitor. The lack of AurB inhibitory activity is hypothesized to minimize on-target hematologic toxicity associated with AurB inhibition. The molecule’s selectivity is intended to allow for continuous dosing at exposures associated with > 90% target inhibition at trough. In an analysis of LY3295668 antiproliferative effects in 560 cancer cell lines, neuroblastoma was among the most sensitive histologies tested. This screen also separately evaluated genomic predictors of response to LY3295668, with MYC/ MYCN amplification identified as among the strongest predictors of sensitivity to this agent. LY3295668 is currently being evaluated in early phase adult trials. The current trial (J10-MC-JZHD) was uniquely designed to hasten time to first-in-child oncology development for a rare unmet need of relapsed/refractory neuroblastoma patients. Methods: Study J1O-MC-JZHD (NCT04106219) is a multicenter, dual collaboration (NANT and ITCC), randomized, open-label, Phase 1 study of oral LY3295668 in children with relapsed/refractory neuroblastoma. A rolling 6 design will be followed for dose escalation in both a monotherapy cohort and a combination cohort testing LY3295668 together with cyclophosphamide and topotecan. The starting monotherapy dose will be equivalent to 80% of the adult maximum tolerated dose. Key eligibility criteria include recurrent/refractory neuroblastoma not amenable to curative treatment, age 2-21 years, mandatory archival tissue submission, ability to swallow capsules, and adequate hematologic and organ function. LY3295668 is administered in capsule form orally BID continuously. Primary objectives include assessments of safety and tolerability of study drug to identify RP2D as monotherapy and combination, and assess antitumor activity. Secondary objectives include assessment of the pharmacokinetic profile as monotherapy and in combination, and assessment of the relationship between study drug exposure and efficacy. Following determination of the RP2Ds, an expansion phase will randomize patients to monotherapy or to the combination arm. Enrollment began 16 Dec 2019 and is ongoing. Clinical trial information: NCT04106219.

Background ETMRs are a newly recognized rare paediatric brain tumor with alterations of the C19MC microRNA locus. Due to varied diagnostic practices and limited clinical data, disease features and determinants of outcome are poorly defined. We performed an integrated clinico-pathologic and molecular analyses of 159 primary ETMRs to define clinical phenotypes, identify predictors of survival and critical treatment modalities for this orphan disease. Methods Primary ETMR patients were identified from the Rare Brain Tumor Consortium (rarebraintumorconsortium.ca) global registry using histopathologic and molecular assays. Event-Free (EFS) and Overall Survival (OS) for 108 patients treated with curative multi-modal regimens were determined using Cox proportional hazard and log rank analyses. Findings ETMRs were predominantly non-metastatic (73%) tumors arising from multiple sites; 55% were cerebral tumors, 45% arose at sites characteristic of other brain tumors. Hallmark C19MC alterations were seen in 91%; 9% were ETMR-NOS. Survival and hazard analyses showed a 6 month median EFS and 2-4yr OS of 27-29% with metastatic disease (HR=0.44, 95% CI 0.26-0.74; p=0.002) and brainstem location (HR=0.40, 95% CI 0.021-0.75; p=0.005) correlating with adverse OS. Gross total resection (GTR: HR=0.38, 95% CI 0.21-0.68; p=0.001), high dose chemotherapy (HDC: HR=0.55, 95% CI 0.31-0.97; p=0.04) and radiation (RT: HR=0.32, 95% CI 0.16-0.60; p=<0.001) correlated with improved EFS and OS in multi-variable analyses. EFS and OS for patients treated with only conventional dose chemotherapy (CC) was 0% and respectively 37%±14% and 32%± 13% for patients treated with HDC. Patients with GTR or sub-total resection (STR) treated with HDC and RT had superior EFS (GTR 73%±14%, p=0.018; STR 67%±19% p=0.009) and OS (GTR 66%±17%, p=0.05; STR 67%±16%, p=0.005). Amongst 21 long-term survivors (OS 24-202 months); 38%, 24% and 24% respectively received craniospinal, focal or no RT. Interpretation Prompt molecular diagnosis and post-surgical treatment with multi-modal therapy tailored to patient-specific risk features improves ETMR survival. Funding This work was supported by the Canadian Institute of Health Research Grant No. 137011, Canada Research Chair Awards to AH. Funds from Miracle Marnie, Phoebe Rose Rocks, Tali’s Funds, Garron Cancer Centre, Grace’s Walk, Meagan’s Walk, Nelina’s Hope and Jean Martel Foundation are gratefully acknowledged. SK and PS were respectively supported by the Australian Lions Children’s Cancer Foundation and the Spanish Society of Pediatrics, Consejería de Salud y Familias de la Junta de Andalucía Project EF-0451-2017.

Abstract Extra neural metastases of infant medulloblastoma portend poor prognosis. Previous reports were in patients receiving treatment with radiation alone or patients with ventriculoperitoneal shunt (VPS). Recently with multimodal therapy, reports of extra-neural medulloblastoma are rarely reported. We report two patients with stage M3 MYC-Activated Infant Medulloblastoma who received aggressive therapy yet developed extra-neural relapses. The first case was a 2-year-old male who underwent gross total resection, which was complicated by hydrocephalus requiring VPS placement. He completed treatment as per ACNS0334 and achieved a near-complete response. Next, he received four cycles of five drug anti-angiogenic therapy followed by 2 cycles of expanded access therapy with I-3F8 antibody. He progressed both in brain and spinal cord, then received palliative craniospinal irradiation with boost. Two months following radiation, he died of disease with significant pancytopenia and hypoechoic nodules throughout the liver, suggestive of disseminated disease. Our second patient is a five-year-old girl, who was diagnosed at age two. She achieved a CR after treatment as per ACNS0334. She then enrolled on a clinical trial with Difluoromethylornithine (DFMO) for three months. On initial disease evaluation, she had progression in brain and spine. She underwent palliative radiation with craniospinal irradiation and boost with concurrent Indoximod on phase 2 clinical trial. Following radiation, she received compassionate use indoximod and temadar for 24 months and remained in CR. Three months after stopping therapy, she progressed to left orbit, pelvis and ribs. She is currently receiving palliative care. MYC-activated medulloblastoma has a very poor outcome and requires multimodal including radiation to achieve remission. Despite aggressive therapy, disease is highly evasive and can spread extracranially to multiple areas including bones, bone marrow, liver, and abdomen. Novel therapies and more exhaustive surveillance regiments need to be developed to limit extracranial dissemination and achieve more durable remissions.