Abstract CT025: Dabrafenib plus trametinib in BRAF V600E-mutant high-grade (HGG) and low-grade glioma (LGG)

Author(s):  
Vivek Subbiah ◽  
Alexander Stein ◽  
Martin van den Bent ◽  
Antje Wick ◽  
Filip Y. de Vos ◽  
...  
2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii232-ii233
Author(s):  
Anne Marie Barrette ◽  
Lasse Meyer ◽  
Yoko Hirata ◽  
Stefan Grossauer ◽  
Edbert Lu ◽  
...  

Abstract Pediatric low-grade glioma (pLGG), the most common brain cancer in children, is difficult to treat especially at recurrence. The BRAF V600E mutation is the second most common mutation in pLGG, and in a high-risk group for progression is associated with deletion of the tumor suppressor CDKN2A. A better understanding of the factors contributing to progression, in particular the role of the immune infiltrate is needed, but studies have been hindered by the lack of low-grade glioma mouse models. We utilized transgenic mice with a cre-activatable (CA) allele of BRAF V600E to generate endogenous models for low-grade gliomas. We found that BRAF V600E expression cooperates with hemizygous CDKN2A deletion to induce low-grade gliomas, with tumors forming at a greater latency than by homozygous deletion. Cell line derivatives from low-grade lesions continue to grow slower upon orthotopic injection than those we previously derived from high-grade tumors. Murine LGG can progress to higher grade tumors within the mouse lifespan and we observe exomic changes and alterations in the tumor immune infiltrate associated with progression, the details of which will be discussed at the meeting. High-grade cells’ phenotypic changes within in vivo passage are accompanied by exomic changes. The high-grade glioma immune infiltrate is altered by dual MAPK pathway inhibition with dabrafenib and trametinib. Adding dual immune checkpoint inhibition by anti-PD-L1 and anti-CTLA-4 antibodies significantly extends survival of dabrafenib-trametinib dual treatment. Human BRAF V600E mutant tumors reportedly have a higher tumor immune infiltrate than that of BRAF wildtype gliomas, consistent with our murine RESULTS: Here we present a novel model for BRAF V600E mutant gliomas in mice that has a frequent rate of progression, similar to human BRAF V600E mutant gliomas, and an active immune infiltrate in high grade tumors which makes them susceptible to the immunostimulatory effects of dual checkpoint inhibition.


2019 ◽  
pp. 175-179
Author(s):  
Francesco Fabbiano ◽  
Jacopo Scaggiante ◽  
Andrea Wlderk ◽  
Gualtiero Innocenzi ◽  
Sergio Paolini ◽  
...  

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 10008-10008
Author(s):  
Carl E. Allen ◽  
Olive Eckstein ◽  
Paul M. Williams ◽  
Sinchita Roy-Chowdhuri ◽  
David R Patton ◽  
...  

10008 Background: The NCI-Children’s Oncology Group (COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial assigns patients age 1 to 21 years with relapsed or refractory solid tumors, lymphomas, and histiocytic disorders to phase 2 treatment arms of molecularly-targeted therapies based on genetic alterations detected in their tumor. Arm E evaluated the MEK inhibitor selumetinib (ARRY-142886) in patients whose tumors harbored activating alterations in the MAPK pathway ( ARAF, BRAF, HRAS, KRAS, NRAS, MAP2K1, GNA11, GNAQ hotspot mutations; NF1 inactivating mutations; BRAF fusions). Methods: Patients received selumetinib 25 mg/m2/dose (max 75 mg/dose) PO BID for 28-day cycles until disease progression or intolerable toxicity with response assessments obtained every 2-3 cycles. The primary endpoint was objective response rate (ORR); secondary endpoints included progression-free survival (PFS). Patients with low grade glioma were excluded. Results: A total of 21 patients (median age 14 years; range 5-21) were enrolled between 10/2017 and 8/2019, with 20 patients evaluable for response. Diagnoses were high grade glioma (HGG; n = 8), rhabdomyosarcoma (n = 7), adenocarcinoma (n = 2), and one each of MPNST, endodermal sinus/yolk sac tumor, plexiform neurofibroma (PN), and neuroblastoma. MAPK pathway alterations detected consisted of inactivating NF1 mutations (n = 8), hotspot mutations in KRAS (n = 8), NRAS (n = 3), and HRAS (n = 1), and BRAF V600E (n = 2). No objective responses were observed. Three patients had a best response of stable disease (HGG with NF1 mutation, 6 cycles; HGG with KRAS mutation, 12 cycles; PN with NF1 mutation, 13 cycles prior to removal for dose-limiting toxicity). Six-month PFS was 15% (95% CI: 4%, 34%). Adverse events that were deemed possibly, probably, or definitely attributable to study drug included one case each of grade 3 uveitis, lymphopenia, and thromboembolic event; one grade 4 CPK elevation; and one grade 5 thromboembolic event. Conclusions: Selumetinib did not result in tumor regression in this cohort of children and young adults with treatment-refractory tumors with activating MAPK pathway alterations. Of note, two patients with HGG initially had stable disease, but ultimately progressed after 6 and 12 cycles, respectively. Selumetinib has previously demonstrated activity in low grade glioma and PN and is now FDA-approved for PN. The results of our study indicate that MAPK pathway mutation status alone is insufficient to predict response to selumetinib monotherapy. It is likely that selumetinib and other MEK inhibitors will require combination with targeted or cytotoxic agents for optimal efficacy in children with persistent or progressive cancers after front-line chemotherapy. Clinical trial information: NCT03213691. Clinical trial information: NCT03155620.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi246-vi246
Author(s):  
Ahmad Almekkawi ◽  
Tarek El Ahmadieh ◽  
Karl Abi-Aad ◽  
Salah Aoun ◽  
Najib EL Tecle ◽  
...  

Abstract BACKGROUND 5-aminolevulinic acid is a reliable tool for optimizing high-grade glioma resection. However, its efficacy in low-grade glioma resection remains unclear. OBJECTIVE To study the role of 5-aminolevulinic acid in low-grade glioma resection and assess positive fluorescence rates and effect on the extent of resection. METHODS A systematic review of PubMed, Google Scholar, and Cochrane was performed from the date of inception to February 1, 2019. Studies that correlated 5-aminolevulinic acid fluorescence with low-grade glioma in the setting of operative resection were selected. Studies with biopsy only were excluded. Positive fluorescence rates were calculated. Quality index of the selected papers using the Downs and Black criteria checklist was provided. RESULTS Twelve articles met the selection criteria with 244 histologically-confirmed low-grade glioma patients who underwent microsurgical resection. All patients received 20 mg/kg body weight of 5-aminolevulinic acid. Only 60 patients (n=60/244; 24.5%) demonstrated visual intra-operative 5-aminolevulinic acid fluorescence. The extent of resection was reported in 4 studies, however, the data combined low- and high-grade tumors. Only 2 studies reported on tumor location. Only 3 studies reported on clinical outcomes. The Zeiss OPMI Pentero microscope was most commonly used across all studies. The average quality index was 14.58 (range: 10–17) which correlated with an overall good quality. CONCLUSION There is an overall low correlation between 5-aminolevulinic acid fluorescence and low-grade glioma. Advances in visualization technology and using standardized fluorescence quantification methods may further improve the visualization and reliability of 5-aminolevulinic acid fluorescence in low-grade glioma resection.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10504-10504 ◽  
Author(s):  
Jason R. Fangusaro ◽  
Arzu Onar-Thomas ◽  
Tina Young-Poussaint ◽  
Shengjie Wu ◽  
Azra H Ligon ◽  
...  

10504 Background: A greater understanding of the Ras-MAP kinase-signaling pathway in pediatric low-grade glioma (LGG) paired with the availability of potent selective inhibitors has enhanced the ability to target this pathway with therapeutic intent. Methods: The PBTC conducted a multi-institutional phase II study (NCT01089101) evaluating selumetinib (AZD6244, ARRY-142886), a MEK I/II inhibitor, in children with recurrent/refractory LGG assigned to 6 strata and treated at 25 mg/m2/dose PO BID for up to two years. Here we present the data from three of these strata. The remaining strata are still accruing patients. Results: Stratum I included children with non-NF-1 and non-optic pathway recurrent/refractory pilocytic astrocytoma (PA) harboring BRAF aberrations (BRAF V600e mutation or the BRAF-KIAA 1549 fusion). Eight of 25 (32%) patients achieved a partial response (PR) with 2-year PFS of 66+/-11%. Two of 7 (29%) patient tumors with a BRAF V600e mutation and 6/18 (33%) with a BRAF KIAA-1549 fusion had a PR. Stratum 3 enrolled NF-1-associated LGG. Tissue for tumor BRAF evaluation was not required for eligibility. Ten of 25 (40%) achieved PR with a 2-year PFS of 96+/-4%. Only one patient progressed while on treatment. Stratum 4 included children with non-NF-1 optic pathway/hypothalamic LGG. Tissue for tumor BRAF evaluation was not required for eligibility. Two of 16 (12.5%) had a PR with a 2-year PFS of 65+/-13%. The BRAF aberration status of the responders in strata 3 and 4 is mostly unknown. All responses were confirmed centrally and seven patients remain on treatment. The most common toxicities were grade 1/2 CPK elevation, diarrhea, hypoalbuminemia, elevated AST and rash. Rare grade 3/4 toxicities included elevated CPK, rash, neutropenia, emesis and paronychia. Conclusions: Selumetinib was effective in treating children with recurrent/refractory LGG, including those with NF-1 associated LGG and PA harboring BRAF V600e mutation or BRAF-KIAA 1549 fusion. Larger prospective studies are necessary to determine the future, specific role of this agent in treating children with LGG harboring specific molecular aberrations. Clinical trial information: NCT01089101.


2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i34-i34
Author(s):  
Sage Green ◽  
Andrew Walter ◽  
Joseph Piatt ◽  
Gurcharanjeet Kaur

Abstract Objective To describe safety and efficacy of dual targeted therapy with dabrafenib (BRAFi) and trametinib (MEKi) in an infant with inoperable low grade glioma with BRAF V600E mutation. Introduction Safety and efficacy of dual targeted therapy with BRAFi and MEKi for pediatric low grade glioma (pLGG) is currently being evaluated, however, infants are usually not included in these clinical trials. Case We report a case of a 2-month-old male infant who presented with involuntary movements and gaze deviation concerning for seizures. MRI brain revealed a tumor involving the medulla, T2/FLAIR dimensions: 2.5 x 2.2 x 2.7 cm and drop metastases to the cauda equina. An EEG ruled out seizure activity. Tumor biopsy was performed revealing Ganglioglioma, WHO grade I. IHC and somatic next generation sequencing revealed BRAF V600E point mutation. Germline testing was negative. Due to tumor progression on traditional chemotherapy, compassionate use of dual targeted therapy with dabrafenib (5.25mg/kg/day divided twice daily) and trametinib (0.032mg/kg daily) was initiated at 4.5 months of age. The patient has tolerated dual therapy for nearly 1 year without significant toxicity with exception of grade I skin rash. In terms of functional outcomes, previously noticed vocal cord paresis has resolved and our patient with global developmental delay continues to make developmental gains, albeit slowly. On recent neuroimaging, pLGG has continued to grow T2/FLAIR dimensions: 3.5 x 3.5 x 3.7 cm, however, combination therapy has halted the rate of growth of this tumor. Conclusion To our knowledge, our patient is the youngest to receive combination of BRAFi and MEKi. Tumor targeted therapy could be an important treatment option for infants with inoperable pLGG where aggressive surgery and radiation therapy are associated with significant morbidity. Multi-institutional clinical trials that include infants are needed to further comment on safety and efficacy of these agents.


2020 ◽  
Author(s):  
Musthafa Raswoli ◽  
Liana Nobre ◽  
Cynthia Hawkins ◽  
Ute Bartels ◽  
Uri Tabori ◽  
...  

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10503-10503
Author(s):  
Michal Zapotocky ◽  
Scott Ryall ◽  
Anthony Arnoldo ◽  
Matthew Mistry ◽  
Alvaro Lassaletta ◽  
...  

10503 Background: RAS/MAPK pathway mutations have been identified as the major drivers of pediatric low-grade glioma (pLGG). The impact of these alterations on outcome and response to therapy is still unknown. Methods: We performed a large population based study of all pLGG diagnosed from 1985-2015. Detailed treatment and very long term outcome data was collected on all patients. Known pLGG-related alterations were detected using NanoString and QX200™Droplet Digital™PCR. Molecular data was correlated with outcome and response to chemotherapy. Results: In our cohort of 614 patients, BRAF was found to be altered in 57% and wild-type (WT) in 43% of patients without neurofibromatosis 1 (NF1). Among BRAF-WT we identified H3.3K27M, FGFR1-TACC1, MYBL1 and other alterations. Molecular alterations stratified pLGG into several risk groups. Ten-year progression free survival (PFS) was 72.3% for NF1, 69.5% for KIAA1549-BRAF, 53.5% for BRAF-WT, 30.3% for BRAF-V600E and 0% for H3.3K27M mutations (p < 0.0001). Similarly, overall survival (OS) at 10 years delineated difference between excellent survival of KIAA1549-BRAF and NF1 compared to BRAF-V600E and BRAF-WT (p = 0.0005). Interestingly, all patients with FGFR1-TACC1 and MYBL1 were alive despite observed progressions. Strikingly, response to chemotherapy determined by changes in tumor size at 6 months of therapy correlated with pLGG alteration. Objective response to first line chemotherapy was observed in 46% of patients with KIAA1549-BRAF and 35% of NF1. In contrast, only 15% BRAF-V600E and 18% BRAF-WT responded and 41% tumors grew after six months of chemotherapy. Moreover, 5-year PFS after chemotherapy was strikingly low for BRAF-V600E and BRAF-WT (25% and 31.9% respectively) compared to KIAA1549-BRAF (50%) and NF1 (76.7%) (p = 0.001). This translated to decreased OS for BRAFV600E and BRAF-WT patients (p = 0.042). Conclusions: Our study provides evidence that molecular alterations dictate the outcome of pLGG. KIAA1549-BRAF harbors excellent prognosis and choice of therapy should be made in favor of less toxic agents to minimize deleterious late effects. In contrast, poor prognosis is associated with lack of response to chemotherapy in BRAF-V600E and BRAF-WT tumors.


Author(s):  
Sanjeet Pandey ◽  
Brijesh Bharadwaj ◽  
Himanshu Pandey ◽  
Vineet Kr. Singh

Brain is recognized as one of the complex organ of the human body. Abnormal formation of cells may affect the normal functioning of the brain. These abnormal cells may belong to category of benign cells resulting in low grade glioma or malignant cells resulting in high grade glioma. The treatment plans vary according to grade of glioma detected. This results in need of precise glioma grading. As per World Health Organization, biopsy is considered to be gold standard in glioma grading. Biopsy is an invasive procedure which may contains sampling errors. Biopsy may also contain subjectivity errors. This motivated the clinician to look for other methods which may overcome the limitations of biopsy reports. Machine learning and deep learning approaches using MRI is considered to be most promising alternative approach reported by scientist in literature. The presented work were based on the concept of AdaBoost approach which is an ensemble learning approach. The developed model was optimized w.r.t to two hyper parameters i.e. no. of estimators and learning rate keeping the base model fixed. The decision tree was us ed as a base model. The proposed developed model was trained and validated on BraTS 2018 dataset. The developed optimized model achieves reasonable accuracy in carrying out classification task i.e. high grade glioma vs. low grade glioma.


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