Citations

2046 Background: Vorinostat (VOR) is a histone deacetylase inhibitor that represents a rational targeted agent in GBM treatment. Given its single-agent activity in recurrent disease (Galanis,et al, 2009) and radiosensitizing properties, this phase I/II trial was designed to test the addition of VOR to standard chemoradiation in newly diagnosed GBM patients (pts): the phase I portion of the trial is the focus of this report. Methods: A standard cohorts of three design was used to assess the safety of VOR in combination with RT and concomitant TMZ and establish the phase II dose of the combination. VOR was given orally days 1 - 5 every wk beginning with the first dose of RT (total dose 60 Gy) and (75mg/m²/day). Following a 4 - 6 week rest, pts received up to 12 cycles of standard adjuvant TMZ in combination with VOR on days 1-7 and 15 – 21 of each cycle; dose was based on NABTT trial 04-03 (Lee, et al, 2012). Results: The phase I component is complete with 15 pts, 12 pts at dose level 0 (VOR 300 mg/day days 1 - 5, weekly x 6 wks), and 3 pts at dose level 1 (VOR 400 mg/day, days 1 – 5 weekly x 6 wks) in combination with RT/TMZ. Dose limiting toxicity (DLT) in dose level 1 included grade 3 fatigue in 2 pts, grade 3 wound dehiscence in 1 pt, and grade 4 neutropenia and thrombocytopenia in 1 pt. In dose level 0, 1/6 pts had DLT (gr 3 dyspnea). An MTD expansion cohort of 6 additional patients was added to dose level 0; one patient experienced grade 4 thrombocytopenia and grade 3 fatigue, and 1 patient experienced grade 3 febrile neutropenia. In the 12 pts treated in the phase II dose, most common toxicities were hematologic, including lymphopenia (gr 3/4 in 66.7%), thrombocytopenia (gr 3 in 16.7%, gr 4 in 16.7%) and neutropenia (gr 3 in 16.7%, gr 4 in 8.3%). Grade 3 fatigue was observed in 8.3% of the pts. Conclusions: MTD for VOR in combination with TMZ/RT in newly diagnosed GBM patients is 300 mg/d, days 1 - 5 weekly during RT. Toxicity was primarily hematologic. This dose was used in the recently completed phase II trial of the combination (110 pts). RNA expression profiling in patient samples is in process to assess vorinostat responsive signatures observed in preclinical models. Clinical trial information: NCT00731731.

2014 Background: PFS6 is low (2.3%) and med OS brief (4 mos) for recurrent GBM pts who progress after prior RT/TMZ and bevacizumab (Bev), and then receive non-Bev containing regimens (Reardon et al, Br J Canc 2012). Following VEGFi exposure, tumor cell resistance potentially may result from activation of Ras/Raf/MEK/ERK (MAPK) and PI3K/Akt/mTOR signaling pathways. Temsirolimus (mTOR inhibitor) and sorafenib (Raf, PDGFR, VEGFR inhibitor) have previously shown limited single agent activity in GBM. Methods: Recurrent GBM pts who showed radiographic progression despite prior surgery, RT + temozolomide, and VEGFi (initially or at recurrence) received sorafenib 200 mg PO bid and temsirolimus 20 mg IV weekly (the NCCTG N0572 phase I MTD) until progression. All pts had received < 2 prior chemo regimens. A two-stage design was used, with 90% power to detect an increase in PFS6 from 8% to 23%, requiring 41 evaluable pts. The primary endpoint was PFS6; secondary endpoints included OS, TTP, and ORR. Toxicity (TOX) was assessed using CTC ver 3.0. Results: 44 evaluable pts were accrued. Four of the first 40 (10%) reached PFS6, but this did not meet the pre-study threshold for success. Median TTP was 1.8 mos. (40 events, 95% CI: 1.5 – 2.3); median OS was 5 mos. (36 events, 95% CI: 6.6 – 3.1), and no objective responses were reported. Eight pts are alive; 4 have not progressed (median F/U 3.1 mos.; max, 12.2 mos.). Grade 3+ non-heme AE were observed in 51% (23/45; fatigue-5, hypophosphatemia-7, hypercholesterolemia-5, hypertriglyceridemia-5). One grade 4 hematologic AE (thrombocytopenia) occurred. 13.3% (6/45 pts) went off due to TOX, and 71.1% (32/45) due to disease progression. Conclusions: Sorafenib plus temsirolimus was tolerable, but the primary endpoint threshold for success (PFS6) was not met in post-VEGFi recurrent GBM patients. Nevertheless, PFS6 (10%) and OS (5 mos.) compared favorably to contemporary series of Bev-refractory, recurrent GBM pts who are subsequently treated with a non-Bev containing regimen. Supported by NCI CA-25224. Clinical trial information: NCT00329719.

2032 Background: Dasatinib is a potent oral ATP competitive multi-targeted kinase inhibitor of multiple members of the Src kinase family, known to be involved in gliomagenesis and invasion. N0877 is a phase I/randomized phase II trial evaluating the combination of dasatinib, radiation (RT) and temozolomide (TMZ) in newly diagnosed GBM. The phase I portion has been completed and is the focus of this report. Methods: A cohorts-of-3 design was used to assess the safety of dasatinib in combination with RT and concomitant TMZ, and establish the phase II dose of the combination. Dasatinib was given orally for 42 days, beginning with the first day of RT (total dose 60 Gy) and first dose of TMZ (75 mg/m2/d). A 24 - 42 day rest (cycle 2) followed the RT/TMZ/dasatinib. Patients (pts) were observed for DLT to the end of cycle 2. Patients then received 6 cycles (28 day cycles) of dasatinib (once daily) and TMZ (days 1-5). At the completion of 6 cycles of TMZ + dasatinib, pts stay on dasatinib only (28 day cycles) until progressive disease. Results: Phase I component is complete with 13 patients (3 at dose level 0, 3 at dose level 0-A, 7 at dose level 1). One patient in dose level 1 had to be replaced due to the development of unrelated medical issues. One DLT (grade 4 pancytopenia) was observed in 1 patient at dose level 0 (50mg bid) and one DLT (grade 3 rash) was observed in 1 patient at dose level 1 (150mg qd). MTD of dasatinib was determined to be 150mg daily. Most common adverse events throughout the entire study period were hematologic with the most common toxicity being lymphopenia (grade 3 in 69% of patients, grade 4 in 8%). Other toxicities attributed to treatment and occurring in > 10% of patients included anemia (31%), neutropenia (15%), and fatigue(15%). Best response was stable disease in 10 patients, progressive disease in 1 patient, and not evaluable in 2. Conclusions: MTD for dasatinib in combination with TMZ and RT in newly diagnosed GBM patients is 150mg daily. Toxicity was primarily hematologic with minimal non-hematologic events. This dose is currently being used in the ongoing placebo-controlled, randomized phase II trial.

Abstract BACKGROUND Central nervous system (CNS) germ cell tumors (GCT) are rare and complex pediatric neoplasms, the optimal management of which remains an area of active investigation. OBJECTIVE To present an updated cohort study, with particular attention to novel diagnostic methods and posttreatment clinical phenotypes. METHODS A single-institution cohort study of 80 primary, neurosurgically managed, CNS GCTs was conducted at Mayo Clinic, 1988-2017. RESULTS Postchemotherapy resection (eg, second-look surgery) was frequently required (27.0%), especially after adjuvant therapies for nongerminomatous GCTs (NGGCTs; 14 of 28 cases, excluding mature teratoma) and significantly associated with pineal lesions, as compared to neurohypophyseal or bifocal lesions (43.6% vs 5.9% vs 6.7%, P = .004), a finding that retained statistical significance after adjusting for index extent of resection and histology ( P = .04). Essentially every NGGCT case underwent at least 1 craniotomy, either on presentation, as second-look surgery, or following local recurrence. Mature teratomatous tissue was highly incident in second-look specimens (84.2%), even among lesions initially diagnosed as germinomas. Pretreatment cerebrospinal fluid (CSF) cell fraction analysis demonstrated an association between single lesions and neutrophil predominance, whereas nongerminomatous GCTs were associated with increased monocyte fractions. CONCLUSION CNS GCTs are clinically heterogeneous lesions, resulting in numerous opportunities for improved understanding and clinical management via novel diagnostic and therapeutic protocols. Samples from second-look surgeries for recurrent germinomas frequently demonstrate teratomatous tissue, suggesting possible underdiagnosis of mixed GCTs—particularly among pineal lesions. GCT subtypes demonstrate differential cell fraction distributions on CSF analysis, a novel and perhaps diagnostically helpful finding that requires validation in external cohorts.

1562 Background: Prior studies have shown additive effects of CPT-11 in combination with BCNU, and radiosensitizing effects of CPT-11 in gliomas. Methods: All pts had GBM by central review prior to registration. With MTD based on a pilot study (Arm A), those not receiving anticonvulsants (non-EIAC, Arm C) received RT with concomitant CPT-11 (125 mg/M2/wk × 4, cycle 1), followed by BCNU (100 mg/M2 q 6 wk) + CPT-11 (75 mg/M2/wk × 4, q 6 wks, cycles 2–5) beginning within 4 wks of RT. Pts on EIAC (Arm B) received CPT-11 (400 mg/M2/wk × 4, cycle 1) during RT, then post-RT BCNU (100 mg/M2 q 6 wk) + CPT-11 (400 mg/M2/wk q 6 wks, cycles 2–5). Dose de-escalations (but no escalations) were allowed. Toxicity was graded by CTC v. 3.0. Primary endpoint was overall survival at 12 mo (OS12), with a interim futility analysis after 12 mos. follow up in the first 35 patients. 18 “successes” (survival > 12 mo) were required to proceed. Results: There were 56 pts treated (20 Arm A, 12 Arm B, 24 Arm C). Six pts on Arm A developed toxicity at the pilot CPT-11 cycle 2–5 dose of 125mg/M2, requiring reduction (75 mg/M2) for the remainder of Arm A and all Arm C pts. The decision rule for the first 35 patients was not met, with inclusion of the 6 Arm A pts (14 successes, 19 failures, 2 incomplete data) or without these pts ( 13 successes, 20 failures, 2 incomplete). In the 35 pts with mature data, the best confirmed response was PR in 2 (6%), REGR in 4 (11%) and stable (>4 wks, STAB) disease in 7 (20%). For the 56 pts (51 with mature data), PR, REGR and STAB were noted in 4%, 16%, and 39% respectively. Reason for end of treatment (N=56) was: completion of study treatment (13%); pt refusal (11%); adverse event (9%); progression (39%); all cause death (9%); too early (13%) or other (7%). In the 51 pts whose data is mature, progression free survival at 6 mos (PFS6) was 29.8% (95% CI: 19.1, 46.3); PFS12 was 16.5% (95% CI: 8.3, 32.9) and OS at 12 mos was 45.4% (95% CI: 32.7, 63). Overall median survival was 10.7 mos (95% CI: 7.8, 14.5). Conclusions: Although limited activity (PR+REGR+STAB) of this combination was demonstrated, the decision rule (minimum OS12 “successes”) was not reached, and tolerability of this regimen was only moderate. We consider the regimen as not superior to results obtained with other regimens in prior NCCTG studies. No significant financial relationships to disclose.

1521 Background: Gliomas are known to progress from low to high grade at relapse, but the frequency is not well understood. It is unclear whether survival of these pts differ as a function of histologic subtype, and as measured from initial diagnosis and from relapse; yet such pts are frequently combined in clinical trials. Methods: Central review of paired glioma tissues obtained at initial diagnosis (DX) and recurrence was performed in 208 pts enrolled in prospective NCCTG trials (recurrence ≤ 90 d excluded). Kaplan-Meier, log rank, ANOVA, and chi-square tests were utilized. Results: Relapse from low (1–2) to high grade (3–4) occurred in 18/42 (43%) oligodendrogliomas (oligo), 28/41 (68%) oligoastrocytomas (OA), and 14/20 (70%) astrocytomas (astro); p=0.031. There were differences in median OS (in yrs; 95% CI) from initial DX: oligo-7.5 (5.0, 12.6); OA-4.5 (3.8, 5.6); and astro-3.3(1.8, 5.1), p=0.002; and OS from high grade recurrence: oligo-2.1 (0.9,3.0); OA-1.0 (0.8,1.3); and astro-0.7 (1.8, 5.1); p=0.02. Median OS from initial DX (yrs, 95% CI) also differed between primary (initial DX) GBM-1.7 (1.5–2.2); secondary (at recurrence) GBM-3.7 (2.8, 4.2) and non-GBM (initial+recurrence)- 5.5, (4.9–7.0) respectively, p < 0.001. Mean time to recurrence (TTR), (yrs ± S.D.) also differed: 1.1±1.1; 2.9±1.8; and 4.0±2.9, respectively, p < 0.001; as did median OS from recurrence (yrs, 95% CI) [0.7 (0.5, 1.1); 0.6, (0.5, 1.0); and 1.6 (1.1, 2.1), respectively], p <0.001. OS differed between primary vs. secondary GBM from time of initial DX (p=0.041) and also from recurrence (p=0.017). Conclusions: Low grade astro and OA progressed to grade 3–4 more frequently than did pure oligo; these groups had significant differences in OS from initial diagnosis and from recurrence. There were significant differences in OS between pts with primary and secondary GBM from initial diagnosis and recurrence. These data have important implications in design of clinical trials. [Table: see text] No significant financial relationships to disclose.

1520 Background: Multiple variables may impact endpoints utilized to assess efficacy of investigational therapies for pts with recurrent gliomas. Understanding the nature of these variables should aid interpretation of results. Methods: 583 pts were enrolled to 15 consecutive recurrent glioma clinical trials conducted between 1980 and 2004. Identical patient, tumor, treatment and time variables were identified for each trial. Central neuropathology review was completed and pts were grouped by WHO diagnoses. Pts alive and progression-free at 6 months after start of treatment were a PFS6 ‘success’. Pts whose outcome was progression at first evaluation were classified as “Immediate Progression (ImmProg)”. Response was defined as regression, partial regression, or complete regression in the absence of worsening neurologic symptoms or increased corticosteroid dose. Univariable and multivariable Classification and Regression Trees (CART) models were used to identify factors associated with OS, PFS, PFS6, ImmProg, and Response. Results: Variables associated with outcomes for each endpoint assessed by CART models are shown in Table below. Conclusions: In clinical trials of recurrent glioma, age, PS, duration of disease, primary and recurrent histologic diagnosis, and primary and recurrent extent of resection are associated with outcomes. These variables should be validated in additional datasets for potential inclusion in reports of future clinical trials. [Table: see text] No significant financial relationships to disclose.

1517 Background: In a previous report, we showed in patients with newly diagnosed anaplastic oligodendrogliomas (AOs) and mixed anaplastic oligoastrocytomas (MAOs) that temozolomide (TMZ) can be given concurrently with radiation therapy (RT) with acceptable toxicity. We have now evaluated the efficacy of this regimen and correlated durability of response with tumor 1p/19q genotype. Methods: A phase II study was performed to evaluate the use of pre-RT TMZ followed by concurrent RT and TMZ in patients with newly diagnosed AO or MAO. The primary endpoint was to determine the pre-RT TMZ six-month progression rate, and secondary endpoints included progression-free survival and overall survival. Results: 40 eligible patients were entered into the trial. Thirty-two patients completed 6 months of pre-RT TMZ and concurrent RT and TMZ. Of the remaining eight patients, 4 withdrew due to toxicity and 4 other patients withdrew from study without evidence of toxicity or pre-RT progression. 1p/19q data are available in 37 cases; 23 tumors had loss of heterozygosity (LOH) of both 1p and 19q (double-deleted) while 14 tumors had LOH of either 1p or 19q (n = 3), or no LOH (n = 11). To date, 11 patients have experienced tumor progression; 1p/19q data are available for 10 of these cases (2 are double-deleted (2/23 = 9%), 8 have at least one intact chromosome (8/14 = 57%). Kaplan-Meier analysis demonstrates that progression free survival is significantly better for the double-deleted group (median time to progression not reached) than for the intact group (median time to progression = 15.2 months, p = 0.001). Overall survival is 98% (39/40) with a median follow-up of 17.5 months (2.8 - 31.1 months). Conclusions: LOH of both 1p and 19q is strongly correlated with a durable response of AO and MAO to a combined regimen of chemotherapy and radiation therapy. Tumors that are intact at 1p and/or 19q progress early despite an aggressive therapeutic regimen. These results suggest that future clinical trials should be prospectively stratified by tumor 1p/19q genotype. [Table: see text]

1505 Background: Combined deletion of chromosomes 1p and 19q is associated with improved prognosis in pts with anaplastic oligodendroglioma. We recently discovered that the combined deletion is mediated by a chromosome 1;19 translocation: t(1;19)(q10;p10). The prognostic significance of this alteration in pts with low-grade gliomas is not known. Methods: Paraffin-embedded tumor tissue was obtained from 134 pts enrolled in two NCCTG trials for newly-diagnosed low-grade glioma: 86–72–51: a randomized phase III trial of 50.4 Gy vs 64.8 Gy radiation therapy (RT) and 93–72–02: a phase II trial of PCV for 6 cycles followed by RT. Interphase fusion of a CEP1 probe and a BAC contig probe for 19p12 was used to detect the 1;19 translocation. Analysis of 1p and 19q deletions had been previously performed by FISH. Kaplan-Meier distributions of overall survival (OS) and progression-free survival (PFS) for pts whose tumors did or did not exhibit CEP1/19p12 fusion were compared using the Wilcoxon test. Results: Of 134 pts, CEP1/19p12 fusion testing was informative for 92. CEP1/19p12 fusion prevalence was 55% among 42 oligodendrogliomas, 47% among 30 mixed oligoastrocytomas, and 5% among 20 astrocytomas. 91% of gliomas with and 11% without 1p/19q deletion had CEP1/19p12 fusion (p<0.0001, chi-square test). The frequency of the t(1;19) by tumor histology, as well as median and 5-year progression-free and overall survival are provided in the table . Conclusions: Our results strongly suggest that a t(1;19)(q10;p10) mediates the combined deletion of 1p and 19q in human gliomas. Like combined 1p and 19q deletion, the 1;19 translocation is associated with superior progression-free and overall survival in low-grade oligodendroglioma patients. FISH analysis of the t(1;19) will likely be a more sensitive and specific means to assess 1p and 19q status in patients with gliomas. (Supported in part by CA85799, CA108961 and NCCTG grants CA25224 and CA114740) [Table: see text] No significant financial relationships to disclose.

2004 Background: Vorinostat is a histone deacetylase inhibitor that represents a rational therapeutic target in GBM. Methods: Recurrent GBM patients (pts) having received = 1 prior chemo regimen for progressive disease were eligible. Vorinostat dose was 200 mg bid x 14 days q 3 weeks. We applied a phase II design which had 90% power to declare the regimen active if the study PFS6 rate was 25%, a 15% rate increase over PFS6 in historical controls (10%). Results: 68 patients were treated. Grade 3+ non-hematologic toxicity consisting mainly of fatigue, diarrhea and dehydration occurred in 23% of pts; Grade 3+ hematologic toxicity consisting mainly of thrombocytopenia occurred in 25% of pts. Intra-patient dose escalation to 300 mg bid resulted in higher incidence of grade 3+ thrombocytopenia (45%) and was aborted. Pts receiving enzyme-inducing anticonvulsants (EIAC) had significantly less grade 3 + non-hematologic toxicity (p=0.01) and grade 3/4 thrombocytopenia (p=0.04). Pharmacokinetic analysis showed lower vorninostat C-max and AUC (0–24h) values and higher vorinostat-glucuronide C-max and AUC (0–24h) values in EIAC pts, although this did not reach statistical significance. The trial met the prospectively defined primary efficacy endpoint at the planned interim analysis with 5 of the first 22 patients (23%) being progression-free at 6 mo. RNA array analysis, performed in paired baseline and post-vorinostat treatment samples in a separate subgroup of 5 surgical recurrent GBM pts, who received vorinostat for 6 doses prior to surgery, showed upregulation of E-cadherin (p=0.02), thus indicating a biologic effect of the HDAC inhibitor on the glioblastoma tumors. Histone acetylation, Akt, phospho-Akt, P21Waf1/Cip1 and P27Kip1 expression analysis in all patients and correlation with outcome is ongoing. Conclusions: Vorinostat is well tolerated in recurrent GBM patients. EIAC patients have less toxicity, likely due to increased vorinostat metabolism via glucuronidation. Interim efficacy analysis is indicative of antitumor activity. Final efficacy analysis, RNA array data and correlative tissue analysis will be reported. No significant financial relationships to disclose.