Gill, Jonathan Benjamin

Abstract BACKGROUND Diffuse intrinsic pontine glioma (DIPG) carries a poor prognosis with a median survival of less than 12 months. Histone mutation, K27M, and AKT pathway dysregulation play key roles in tumorigenesis. There is no curative treatment with radiation therapy, which currently remains the standard treatment. METHODS This is a phase I study of vorinostat and temsirolimus in newly diagnosed (stratum 1) and progressive (stratum 2) DIPG. The primary aims are to determine the safety, maximum tolerated dose, and toxicities (NCT02420613). Stratum 1 received radiation concurrently with vorinostat, followed by vorinostat and temsirolimus for up to 10 cycles. Stratum 2 received vorinostat and temsirolimus for up to 12 cycles. In stratum 1, vorinostat was administered daily at 230 mg/m2. The maintenance phase (both strata) included concurrent vorinostat 230 mg/m2 daily and temsirolimus 25 or 35 mg/m2 (Days 1 and 8). RESULTS Six patients were enrolled, three in each stratum. Three of the six patients had confirmed H3 K27M mutations. No dose-limiting toxicity was observed, and most adverse effects were limited to grades 1 or 2, including fatigue, nausea, vomiting, myelosuppression, hyperlipidemia, hyperglycemia, elevated liver enzymes, and creatinine. However, one patient experienced grade 3 leukopenia. Two of the three patients in stratum 1 showed evidence of radiographic response after the chemoradiation phase, of whom one patient had progression-free survival of 12 months and completed the 10 maintenance cycles. All patients at stratum 2 had disease progression with no radiographic response. CONCLUSION Overall, the combination of temsirolimus and vorinostat is well tolerated and safe, prompting the need for larger studies to investigate its efficacy. Due to the small number of patients, the study’s findings are limited, and trends in efficacy should be interpreted with caution.

PURPOSE Pharmacologic therapies for neurofibromatosis type 1-associated plexiform neurofibromas (NF1-PNs) are limited; currently, none are US Food and Drug Administration–approved for adults. METHODS ReNeu is an open-label, multicenter, pivotal, phase IIb trial of mirdametinib in 58 adults (≥18 years of age) and 56 children (2 to 17 years of age) with NF1-PN causing significant morbidities. Patients received mirdametinib capsules or tablets for oral suspension (2 mg/m 2 twice daily, maximum 4 mg twice daily), regardless of food intake, in 3 weeks on/1 week off 28-day cycles. The primary end point was confirmed objective response rate (ORR; proportion of patients with a ≥20% reduction of target PN volume from baseline on consecutive scans during the 24-cycle treatment phase) assessed by blinded independent central review (BICR) of volumetric magnetic resonance imaging. RESULTS Twenty-four of 58 adults (41%) and 29 of 56 children (52%) had a BICR-confirmed objective response during the 24-cycle treatment phase; in addition, two adults and one child had confirmed responses during long-term follow-up. Median (range) target PN volumetric best response was –41% (−90 to 13) in adults and –42% (−91 to 48) in children. Both cohorts reported significant and clinically meaningful improvement in patient- or parent proxy-reported outcome measures of worst tumor pain severity, pain interference, and health-related quality of life (HRQOL) that began early and were sustained during treatment. The most commonly reported treatment-related adverse events were dermatitis acneiform, diarrhea, and nausea in adults and dermatitis acneiform, diarrhea, and paronychia in children. CONCLUSION In ReNeu, the largest multicenter NF1-PN trial reported to date, mirdametinib treatment demonstrated significant confirmed ORRs by BICR, deep and durable PN volume reductions, and early, sustained, and clinically meaningful improvement in pain and HRQOL. Mirdametinib was well-tolerated in adults and children.

BackgroundCurative therapy for ES requires both chemotherapy and local control of primary tumor. There is no universally accepted standard approach to local control modalities. This survey was conducted to determine practice patterns and factors influencing the choice to offer various local control modalities to patients with ES of the spine and pelvis.MethodsThe survey consisted of four scenarios involving a 15‐year‐old girl who presented with Ewing sarcoma of thoracic vertebra, sacrum, iliac wing, and acetabulum with or without neurologic compromise. The questionnaire was sent to oncologists, orthopedic surgeons, and radiation oncologists, asking their recommendations for local control modality.ResultsAmong 94 respondents, radiotherapy was most frequently chosen for sacral tumors (68.1%) and T10 vertebral tumors (46.2%) whereas surgery was preferred for iliac wing pelvic tumors (45.7%) and acetabular tumors (43.6%). Orthopedic surgeons were significantly more likely to offer surgery than radiation oncologists (OR 3.07, 95%CI 1.37‐6.88, P = 0.007). Providers outside North America were more likely to offer combined surgery plus radiotherapy (OR 10.58, 95%CI 5.41‐20.70, P < 0.001).ConclusionConsiderable heterogeneity exists in local control modalities for Ewing sarcoma of the spine and pelvis. Specialty and location of practice may influence treatment recommendations.