azd-6244 and Brain-Neoplasms

Pediatric low-grade gliomas (pLGGs) are the most common childhood brain tumor. Progression-free survival (PFS) is much lower than overall survival, emphasizing the need for alternative treatments. Sporadic (without neurofibromatosis type 1) optic pathway and hypothalamic gliomas (OPHGs) are often multiply recurrent and cause significant visual deficits. Recently, there has been a prioritization of functional outcomes.. We present results from children with recurrent/progressive OPHGs treated on a PBTC (Pediatric Brain Tumor Consortium) phase II trial evaluating efficacy of selumetinib (AZD6244, ARRY-142886) a MEK-1/2 inhibitor. Stratum 4 of PBTC-029 included patients with sporadic recurrent/progressive OPHGs treated with selumetinib at the recommended phase II dose (25mg/m2/dose BID) for a maximum of 26 courses.. Twenty-five eligible and evaluable patients were enrolled with a median of 4 (1-11) previous therapies. Six of 25 (24%) had partial response, 14/25 (56%) had stable disease, and 5 (20%) had progressive disease while on treatment. The median treatment courses were 26 (2-26); 14/25 patients completed all 26 courses. Two-year PFS was 78 ± 8.5%. Nineteen of 25 patients were evaluable for visual acuity which improved in 4/19 patients (21%), was stable in 13/19 (68%), and worsened in 2/19 (11%). Five of 19 patients (26%) had improved visual fields and 14/19 (74%) were stable. The most common toxicities were grade 1/2 CPK elevation, anemia, diarrhea, headache, nausea/emesis, fatigue, AST and ALT increase, hypoalbuminemia, and rash.. Selumetinib was tolerable and led to responses and prolonged disease stability in children with recurrent/progressive OPHGs based upon radiographic response, PFS, and visual outcomes.

Topics: Benzimidazoles; Brain Neoplasms; Child; Humans; Neurofibromatosis 1; Optic Nerve Glioma

Activation of the mitogen-activated protein kinase pathway is important for growth of pediatric low-grade gliomas (LGGs). The aim of this study was to determine the recommended phase II dose (RP2D) and the dose-limiting toxicities (DLTs) of the MEK inhibitor selumetinib in children with progressive LGG.. Selumetinib was administered orally starting at 33 mg/m2/dose b.i.d., using the modified continual reassessment method. Pharmacokinetic analysis was performed during the first course. BRAF aberrations in tumor tissue were determined by real-time polymerase chain reaction and fluorescence in situ hybridization.. Thirty-eight eligible subjects were enrolled. Dose levels 1 and 2 (33 and 43 mg/m2/dose b.i.d.) were excessively toxic. DLTs included grade 3 elevated amylase/lipase (n = 1), headache (n = 1), mucositis (n = 2), and grades 2-3 rash (n = 6). At dose level 0 (25 mg/m2/dose b.i.d, the RP2D), only 3 of 24 subjects experienced DLTs (elevated amylase/lipase, rash, and mucositis). At the R2PD, the median (range) area under the curve (AUC0-∞) and apparent oral clearance of selumetinib were 3855 ng*h/mL (1780 to 7250 ng × h/mL) and 6.5 L × h-1 × m-2 (3.4 to 14.0 L × h-1 × m-2), respectively. Thirteen of 19 tumors had BRAF abnormalities. Among the 5 (20%) of 25 subjects with sustained partial responses, all at the RP2D, 4 had BRAF aberrations, 1 had insufficient tissue. Subjects received a median of 13 cycles (range: 1-26). Fourteen (37%) completed all protocol treatment (26 cycles [n = 13], 13 cycles [n = 1]) with at least stable disease; 2-year progression-free survival at the RP2D was 69 ± SE 9.8%.. Selumetinib has promising antitumor activity in children with LGG. Rash and mucositis were the most common DLTs.

Topics: Adolescent; Benzimidazoles; Brain Neoplasms; Child; Child, Preschool; Disease-Free Survival; Dose-Response Relationship, Drug; Female; Glioma; Humans; Male; Maximum Tolerated Dose; Mitogen-Activated Protein Kinases; Neoplasm Grading; Neoplasm Recurrence, Local; Protein Kinase Inhibitors

Selumetinib is a promising MAP (mitogen-activated protein) kinase (MEK) 1/2 inhibitor treatment for pediatric low-grade gliomas. We hypothesized that MR imaging-derived ADC histogram metrics would be associated with survival and response to treatment with selumetinib.. Children with recurrent, refractory, or progressive pediatric low-grade gliomas who had World Health Organization grade I pilocytic astrocytoma with. Each stratum comprised 25 patients. Stratum 1 responders showed lower values of SD of baseline ADC_total as well as a larger decrease with time on treatment in ADC_total mean, mode, and median compared with nonresponders. Stratum 3 responders showed a greater longitudinal decrease in ADC_total. In stratum 4, higher baseline ADC_total skewness and kurtosis were associated with shorter progression-free survival. When all 3 strata were combined, responders showed a greater decrease with time in ADC_total mode and median. Compared with sporadic OPHG, neurofibromatosis type 1-associated OPHG had lower values of ADC_total mean, mode, and median as well as ADC_enhancement mean and median and higher values of ADC_total skewness and kurtosis at baseline. The longitudinal decrease in ADC_total median during treatment was significantly greater in sporadic OPHG compared with neurofibromatosis type 1-associated OPHG.. ADC histogram metrics are associated with progression-free survival and response to treatment with selumetinib in pediatric low-grade gliomas.

Topics: Benzimidazoles; Brain Neoplasms; Child; Diffusion Magnetic Resonance Imaging; Glioma; Humans; Neurofibromatosis 1; Proto-Oncogene Proteins B-raf

The Ras/Raf/MEK/MAPK signaling cascade is frequently activated in human cancer and serves a crucial role in the oncogenesis of pediatric low‑grade gliomas (PLGGs). Therefore, drugs targeting kinases among the mitogen‑activated protein kinase (MAPK) effectors of receptor tyrosine kinase signaling may represent promising candidates for the treatment of PLGGs. The aim of the present study was to elucidate the anticancer effects of the MEK inhibitor Selumetinib on two low‑grade glioma cell lines and the possible underlying effects on intracellular signal transduction. The two cancer cell lines displayed different levels of sensitivity to Selumetinib, as Res186 cells were resistant (IC50>1 µM), whereas Res259 cells were sensitive (IC50≤1 µM) to MEK inhibition. Despite the different levels of sensitivity, Selumetinib mediated the phosphorylation of AKT and MEK in both cell lines and suppressed the phosphorylated MAPK cascades. In addition, Selumetinib induced cell cycle arrest at the G0/G1 phase by downregulating the expression levels of cyclin D1 and p21 and upregulating those of p27 compared with those in the control cells. A Res259 cell line with acquired resistance to Selumetinib (Res259/R) was next established and biologically and molecularly characterized, and it was demonstrated that addition of a selective cAMP‑dependent protein kinase A inhibitor to Selumetinib overcame drug resistance in Res 259/R cells. In conclusion, the results of the present study provided three low‑grade glioma cell line models characterized by sensitivity, intrinsic and acquired resistance to Selumetinib, which may be usuful tools to study new mechanisms of chemoresistance to MEK inhibitors and to explore alternative therapeutic strategies in low‑grade gliomas for personalization of treatment.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cyclic AMP-Dependent Protein Kinases; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Glioma; Humans; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Neoplasm Grading; Protein Kinase Inhibitors