A Phase III study of radiation therapy (RT) and O?-benzylguanine + BCNU versus RT and BCNU alone and methylation status in newly diagnosed glioblastoma and gliosarcoma: Southwest Oncology Group (SWOG) study S0001.
ABSTRACT: AIMS:To determine the efficacy of methylguanine methyltransferase (MGMT) depletion + BCNU [1,3-bis(2-chloroethyl)-1- nitrosourea: carmustine] therapy and the impact of methylation status in adults with glioblastoma multiforme (GBM) and gliosarcoma. METHODS:Methylation analysis was performed on GBM patients with adequate tissue samples. Patients with newly diagnosed GBM or gliosarcoma were eligible for this Phase III open-label clinical trial. At registration, patients were randomized to Arm 1, which consisted of therapy with O(6)-benzylguanine (O(6)-BG) + BCNU 40 mg/m(2) (reduced dose) + radiation therapy (RT) (O6BG + BCNU arm), or Arm 2, which consisted of therapy with BCNU 200 mg/m(2) + RT (BCNU arm). RESULTS:A total of 183 patients with newly diagnosed GBM or gliosarcoma from 42 U.S. institutions were enrolled in this study. Of these, 90 eligible patients received O(6)-BG + BCNU + RT and 89 received BCNU + RT. The trial was halted at the first interim analysis in accordance with the guidelines for stopping the study due to futility (<40 % improvement among patients on the O6BG + BCNU arm). Following adjustment for stratification factors, there was no significant difference in overall survival (OS) or progression-free survival (PFS) between the two groups (one sided p = 0.94 and p = 0.88, respectively). Median OS was 11 [95 % confidence interval (CI) 8-13] months for patients in the O6BG + BCNU arm and 10 (95 % CI 8-12) months for those in the BCNU arm. PFS was 4 months for patients in each arm. Adverse events were reported in both arms, with significantly more grade 4 and 5 events in the experimental arm. CONCLUSIONS:The addition of O(6)-BG to the standard regimen of radiation and BCNU for the treatment patients with newly diagnosed GBM and gliosarcoma did not provide added benefit and in fact caused additional toxicity.
Project description:PURPOSE:Vandetanib, a tyrosine kinase inhibitor of KDR (VEGFR2), EGFR, and RET, may enhance sensitivity to chemotherapy and radiation. We conducted a randomized, noncomparative, phase II study of radiation (RT) and temozolomide with or without vandetanib in patients with newly diagnosed glioblastoma (GBM). EXPERIMENTAL DESIGN:We planned to randomize a total of 114 newly diagnosed GBM patients in a ratio of 2:1 to standard RT and temozolomide with (76 patients) or without (38 patients) vandetanib 100 mg daily. Patients with age ? 18 years, Karnofsky performance status (KPS) ? 60, and not on enzyme-inducing antiepileptics were eligible. Primary endpoint was median overall survival (OS) from the date of randomization. Secondary endpoints included median progression-free survival (PFS), 12-month PFS, and safety. Correlative studies included pharmacokinetics as well as tissue and serum biomarker analysis. RESULTS:The study was terminated early for futility based on the results of an interim analysis. We enrolled 106 patients (36 in the RT/temozolomide arm and 70 in the vandetanib/RT/temozolomide arm). Median OS was 15.9 months [95% confidence interval (CI), 11.0-22.5 months] in the RT/temozolomide arm and 16.6 months (95% CI, 14.9-20.1 months) in the vandetanib/RT/temozolomide (log-rank P = 0.75). CONCLUSIONS:The addition of vandetanib at a dose of 100 mg daily to standard chemoradiation in patients with newly diagnosed GBM or gliosarcoma was associated with potential pharmacodynamic biomarker changes and was reasonably well tolerated. However, the regimen did not significantly prolong OS compared with the parallel control arm, leading to early termination of the study.
Project description:Abstract Pamiparib, an investigational, selective PARP1/2 inhibitor that has demonstrated potent PARP trapping and ability to cross the blood-brain barrier, showed synergistic cytotoxicity with TMZ preclinically. We report updated safety and antitumor effects from a phase 1b/2 study of pamiparib + RT and/or TMZ in patients with newly diagnosed or R/R GBM (SNO 2018, ACTR-30). The dose-escalation/expansion study has 3 arms: Arm A, pamiparib (2, 4, or 6 weeks) + RT in newly diagnosed GBM patients with unmethylated MGMT promoter (unmethylated-GBM); Arm B, pamiparib (6 weeks) + RT and increasing TMZ dosed in weeks 1 and 5 of RT in newly diagnosed, unmethylated-GBM patients; and Arm C, pamiparib + increasing TMZ doses in methylated/unmethylated R/R-GBM patients. Arm A and B patients receive maintenance treatment post-RT rest period at the Arm C expansion dose/schedule. As of 10 April 2019, accrual was completed for Arms A and C dose-escalation (A: n=20; C: n=17) and continues in the dose expansion (A: n=28/40; C: n=28/30); accrual was completed in dose escalation for B (n=9). Recommended phase 2 doses were established for Arms A (pamiparib 60 mg BID×6 weeks + 6–7 weeks RT) and C (pamiparib 60 mg BID d1–28 + TMZ 60 mg d1–7/28-d cycle). One dose-limiting toxicity (grade 3 febrile neutropenia) was reported in Arm B. Treatment-related adverse events (?10%) were (overall/grade 3 [no grade 4/5]): Arm A, nausea (23%/2%); B, decreased WBC count (11%/11%); C (none). Of patients with tumor assessment post-RT: Arm A (n=17), 1 had cPR, 1 uPR, and 9 SD (disease control rate, 64.7% [95% CI, 38.3–85.8]); C (n=26), 1 had cPR (sustained 12 cycles), 1 uPR, and 5 SD (objective response rate, 7.7% [95% CI, 0.9–25.1]). Pamiparib 60 mg BID + RT/TMZ was generally well tolerated in patients with newly diagnosed or R/R GBM. Clinical trial ID: NCT03150862
Project description:Interstitial chemotherapy plays a pivotal role in the treatment of glioblastoma multiforme (GBM), an aggressive form of primary brain cancer, by enhancing drug biodistribution to the tumor and avoiding systemic toxicities. The use of new polymer structures that extend the release of cytotoxic agents may therefore increase survival and prevent recurrence. A novel core-sheath fiber loaded with the drug carmustine (BCNU) was evaluated in an in vivo brain tumor model. Three-dimensional discs were formed from coaxially electrospun fiber membranes and in vitro BCNU release kinetics were measured. In vivo survival was assessed following implantation of discs made of compressed core-sheath fibers (NanoMesh) either concurrently with or five days after intracranial implantation of 9L gliosarcoma. Co-implantation of NanoMesh and 9L gliosarcoma resulted in statistically significant long-term survival (>150 days). Empty control NanoMesh confirmed the safety of these novel implants. Similarly, Day 5 studies showed significant median, overall, and long-term survival rates, suggesting optimal control of tumor growth, confirmed with histological and immunohistochemical analyses. Local chemotherapy by means of biodegradable NanoMesh implants is a new treatment paradigm for the treatment for brain tumors. Drug delivery with coaxial core-sheath structures benefits from high drug loading, controlled long-term release kinetics, and slow polymer degradation. This represents a promising evolution for the current treatment of GBM.
Project description:Via extensive analyses of genetic databases, we have characterized the DNA-repair capacity of glioblastoma with respect to patient survival. In addition to elevation of O6-methylguanine DNA methyltransferase (MGMT), down-regulation of three DNA repair pathways; canonical mismatch repair (MMR), Non-Homologous End-Joining (NHEJ), and Homologous Recombination (HR) are correlated with poor patient outcome. We have designed and tested both in vitro and in vivo, a monoamine oxidase B (MAOB) specific prodrug, PAM-OBG, that is converted by glioma MAOB into the MGMT inhibitor O6-benzylguanine (O6BG) and the DNA crosslinking agent acrolein. In cultured glioma cells, we show that PAM-OBG is converted to O6BG, inhibiting MGMT and sensitizing cells to DNA alkylating agents such as BCNU, CCNU, and Temozolomide (TMZ). In addition, we demonstrate that the acrolein generated is highly toxic in glioma treated with an inhibitor of Nucleotide Excision Repair (NER). In mouse intracranial models of primary human glioma, we show that PAM-OBG increases survival of mice treated with either BCNU or CCNU by a factor of six and that in a chemoradiation model utilizing six rounds of TMZ/2Gy radiation, pre-treatment with PAM-OBG more than doubled survival time.
Project description:Background: Gliosarcoma (GS) is a rare histopathologic variant of glioblastoma (GBM) characterized by a biphasic growth pattern consisting of both glial and sarcomatous components. Reports regarding its relative prognosis compared to conventional GBM are conflicting and although GS is treated as conventional GBM, supporting evidence is lacking. The aim of this study was to characterize demographic trends, clinical outcomes and prognostic variables of GS patients receiving standardized therapy and compare these to conventional GBM. Methods: Six hundred and eighty GBM patients, treated with maximal safe resection followed by radiotherapy with concomitant and adjuvant temozolomide at a single institution, were retrospectively reevaluated by reviewing histopathological records and tumor tissue for identification of GS patients. Clinico-pathological- and tumor growth characteristics were obtained via assessment of medical records and imaging analysis. Kaplan-Meier survival estimates were compared with log-rank testing, while Cox-regression modeling was tested for prognostic factors in GS patients. Results: The cohort included 26 primary gliosarcoma (PGS) patients (3.8%) and 7 secondary gliosarcoma (SGS) patients (1.0%). Compared to conventional GBM tumors, PGS tumors were significantly more often MGMT-unmethylated (73.9%) and located in the temporal lobe (57.7%). GS tumors often presented dural contact, while extracranial metastasis was only found in 1 patient. No significant differences were found between PGS and conventional GBM in progression-free-survival (6.8 and 7.6 months, respectively, p = 0.105) and in overall survival (13.4 and 15.7 months, respectively, p = 0.201). Survival following recurrence was not significantly different between PGS, SGS, and GBM. Temporal tumor location and MGMT status were found associated with PGS survival (p = 0.036 and p = 0.022, respectively). Conclusion: Despite histopathological and location difference between GS and GBM tumors, the patients present similar survival outcome from standardized treatment. These findings support continued practice of radiation and temozolomide for GS patients.
Project description:Gliosarcoma is a rare variant of glioblastoma (GBM) that exhibits frequent mutations in TP53 and can develop in a secondary fashion after chemoradiation of a primary GBM. Whether temozolomide (TMZ)-induced mutagenesis of the TP53 DNA-binding domain (DBD) can drive the pathogenesis of gliosarcoma is unclear.We identified a case of a primary GBM that rapidly progressed into secondary gliosarcoma shortly after chemoradiation was initiated. Bulk tumor was collected and gliomasphere cultures derived from both the pre- and post-treatment tumors. We performed targeted DNA sequencing and transcriptome analyses of the specimens to understand their phylogenetic relationship and identify differentially expressed gene pathways. Gliomaspheres from the primary GBM were treated with TMZ and then analyzed to compare patterns of mutagenesis in vivo and ex vivo.The pre- and post-treatment tumors shared EGFR, CDKN2A, and PTEN mutations, but only the secondary gliosarcoma exhibited TP53 DBD missense mutations. Two mutations, R110C, and R175H, were identified, each in distinct clones. Both were base transitions characteristic of TMZ mutagenesis. Gene expression analysis identified increased JAK-STAT signaling in the gliosarcoma, together with reduced expression of microRNAs known to regulate epithelial-mesenchymal transition. Ex vivo treatment of the GBM spheres with TMZ generated numerous variants in cancer driver genes, including TP53 and CDH1, which were mutated in the post-treatment tumor.TMZ-induced TP53 gain-of-function mutations can have a driving role in secondary gliosarcoma pathogenesis. Analysis of variants identified in ex vivo TMZ-treated gliomaspheres may have utility in predicting GBM evolutionary trajectories in vivo during standard chemoradiation.
Project description:Gliosarcoma is a very rare brain tumor reported to be a variant of glioblastoma (GBM), IDH-wildtype. While differences in molecular and histological features between gliosarcoma and GBM were reported, detailed information on the genetic background of this tumor is lacking. We intend to fill in this knowledge gap by the complex analysis of somatic mutations, indels, copy number variations, translocations and gene expression patterns in gliosarcomas. Using next generation sequencing, we determined somatic mutations, copy number variations (CNVs) and translocations in 10 gliosarcomas. Six tumors have been further subjected to RNA sequencing analysis and gene expression patterns have been compared to those of GBMs. We demonstrate that gliosarcoma bears somatic alterations in gene coding for PI3K/Akt (PTEN, PI3K) and RAS/MAPK (NF1, BRAF) signaling pathways that are crucial for tumor growth. Interestingly, the frequency of PTEN alterations in gliosarcomas was much higher than in GBMs. Aberrations of PTEN were the most frequent and occurred in 70% of samples. We identified genes differentially expressed in gliosarcoma compared to GBM (including collagen signature) and confirmed a difference in the protein level by immunohistochemistry. We found several novel translocations (including translocations in the RABGEF1 gene) creating potentially unfavorable combinations. Collected results on genetic alterations and transcriptomic profiles offer new insights into gliosarcoma pathobiology, highlight differences in gliosarcoma and GBM genetic backgrounds and point out to distinct molecular cues for targeted treatment.
Project description:PURPOSE:Gliosarcoma is a histologic variant of glioblastoma (GBM), and like GBM carries a poor prognosis. Median survival is less than one (1) year with less than 5% of patients alive after 5 years. Although there is no cure, standard treatment includes surgery, radiation and chemotherapy. While very similar to GBM, gliosarcoma exhibits several distinct differences, morphologically and molecularly. Therefore, we report a comprehensive analysis of DNA copy number changes in gliosarcoma using a cytogenomic DNA copy number (CN) microarray (OncoScan®). METHODS:Cytogenomic DNA copy number microarray (OncoScan®) was performed on 18 cases of gliosarcoma. MetaCore™ enrichment was applied to the array results to detect associated molecular pathways. RESULTS:The most frequent alteration was copy number loss, comprising 57% of total copy number changes. The number of losses far exceeded the number of amplifications (***, <?0.001) and loss of heterozygosity events (***, <?0.001). Amplifications were infrequent (4.6%), particularly for EGFR. Chromosomes 9 and 10 had the highest number of losses; a large portion of which correlated to CDKN2A/B loss. Copy number gains were the second most common alteration (26.2%), with the majority occurring on chromosome 7. MetaCore™ enrichment detected notable pathways for copy number gains including: HOXA, Rho family of GTPases, and EGFR; copy number loss including: WNT, NF-kß, and CDKN2A; and copy number loss of heterozygosity including: WNT and p53. CONCLUSIONS:The pathways and copy number alterations detected in this study may represent key drivers in gliosarcoma oncogenesis and may provide a starting point toward targeted oncologic analysis with therapeutic potential.
Project description:Chloroethylnitrosoureas (CENUs) are an important type of alkylating agent employed in the clinical treatment of cancer. However, the anticancer efficacy of CENUs is greatly decreased by a DNA repairing enzyme, O6-alkylguanine-DNA alkyltransferase (AGT), by preventing the formation of interstrand cross-links (ICLs). In this study, a combi-nitrosourea prodrug, namely, N-(2-chloroethyl)-N'-2-(O6-benzyl-9-guanine)ethyl-N-nitrosourea (BGCNU), which possesses an O6-benzylguanine (O6-BG) derivative and CENU pharmacophores simultaneously, was synthesized and evaluated for its ability to induce ICLs. The target compound is markedly more cytotoxic in human glioma cells than the clinically used CENU chemotherapies ACNU, BCNU, and their respective combinations with O6-BG. In the AGT-proficient cells, significantly higher levels of DNA ICLs were observed in the groups treated by BGCNU than those by ACNU and BCNU, which indicated that the activity of AGT was effectively inhibited by the O6-BG derivatives released from BGCNU.
Project description:The clinical implications of plasmatic cell-free and tumor DNA (cfDNA and ctDNA) are challenging in glioblastoma. This prospective study included 52 consecutive newly diagnosed glioblastoma (n?=?49) or gliosarcoma (n?=?3) patients treated with concomitant temozolomide and radiotherapy (RT-TMZ), followed by a TMZ maintenance phase. Plasma samples were collected at baseline, before RT-TMZ (pre-RT-TMZ) and at the end of adjuvant TMZ, or at the time of progression in cases of progressive disease (PD). The cfDNA concentration was measured with a fluorometric method, and ctDNA was detected using targeted droplet digital PCR. The main objectives were to analyze the associations between cfDNA and ctDNA measurements during the course of treatment with PD and survival. There was a significant decrease in median cfDNA concentration from baseline to pre-RT-TMZ-19.4 versus 9.7 ng/mL (p?<?0.0001)-in the entire cohort. In patients with PD, a significant increase in cfDNA concentration from pre-RT-TMZ to time of PD was observed, from 9.7 versus 13.1 ng/mL (p?=?0.037), respectively, while no difference was observed for nonprogressive patients. Neither the cfDNA concentration at baseline nor its kinetics correlated with survival. ctDNA was detected in 2 patients (3.8%) and only in gliosarcoma subtypes.Trial registration ClinicalTrial, NCT02617745. Registered 1 December 2015, https://clinicaltrials.gov/ct2/show/NCT02617745?term=glioplak&draw=2&rank=1 .