Variant allelic fraction of driver mutations predicts success of genomic methylation classification in CNS tumors

e14035

Background: Whole genome CpG DNA methylation profiling is proving to be an extremely valuable tool in the diagnostic and prognostic classification of central nervous system (CNS) tumors, and is especially adept at discriminating between very different tumors, or tumor subtypes, that are histologically similar. However, like any bulk assay, reliability of methylation-based classification depends on sufficient tumor cellularity, as admixed nonneoplastic elements (e.g., neurons, glial cells, inflammatory cells) have their own unique methylation profiles, and thus can skew the results. Currently, it is recommended that at least 70% of the analyzed specimen be tumor; however, this is based on subjective estimates from light microscopy. Many neoplastic entities have well-known driver mutations that occur in virtually 100% of tumor cells, and next-generation sequencing (NGS) assays can detect those mutations and report their relative amounts in the form of Variant Allelic Fraction (VAF). Since NGS and methylation profiling are now frequently being done on the same tumor block, we sought to determine whether driver mutation VAF affects the accuracy of methylation profiling, and whether VAF can help establish more rigorous cutoffs for quality assurance. Methods: Using NGS and Infinium Epic850K methylation arrays, we evaluated 62 CNS neoplasms representing a range of entities, including TERT promoter-mutant glioblastoma, IDH-mutant astrocytoma, IDH-mutant oligodendroglioma, SHH-driven medulloblastoma, and CTNNB1-driven adamantinomatous craniopharyngioma. Results: VAFs of each driver mutation ranged between 1-60%. Forty-four of 62 cases (71%) had a methylation classification score ≥0.9, the most widely accepted cutoff for a successful result. A fit-of-mixture analysis via CutoffFinder (PMID: 23251644) suggested that the optimal VAF cutoff is 21%. Forty-one of 46 (89%) cases with a VAF of 21% or higher had a methylation classification score ≥0.9, whereas only 3/16 (19%) at or below 21% were classifiable with methylation profiling ( P< 0.0001 by Fisher’s exact test). Nonlinear regression of VAF versus methylation score by least squares fit produced R2= 0.54, with sum of squares = 2.0. Conclusions: These data indicate that VAF can serve as a useful predictor of classification success via methylation profiling, and should be taken into account when interpreting methylation profiling results.

An investigation into the impact of next generation sequencing on the use of targeted treatments in glioblastoma

2035

Background: Next-generation sequencing (NGS) provides clinicians immense amounts of information about a patient’s cancer. NGS allows the detection of a wide range of gene alterations undetectable by older techniques. This has the promise to help guide clinicians in their decision-making as genetic alterations can be both prognostic and predictive. NGS may reveal new treatment options for patients with glioblastoma. The goal of this project was to evaluate how often NGS results influence the use of targeted treatment agents in glioblastoma. This study did not investigate the impact of NGS on reclassification of cancers, prognosis, or treatment decisions outside of the use of targeted therapy. Methods: We conducted a retrospective chart review to see if adult glioblastoma patients received treatments for potentially actionable gene alterations and for fusion variants because of NGS. Here we looked at alterations labeled as actionable from the Tempus company’s NGS results. We collected diagnosis and treatment information from the Electronic Medical Record and from the Electronic Data Warehouse. We examined if patients after receiving NGS would receive targeted treatment, as that likely indicated these treatments were given due to NGS indication. We excluded cytotoxic chemotherapy agents and bevacizumab as these therapies are utilized regardless of a targeted gene indication. This analysis excluded treatments received in clinical trials in which enrollment was independent of NGS. This analysis looked at the proportion of patients with actionable alterations that were treated with targeted agents. Results: 261 glioblastoma patients were found on NGS to have mutations which were potentially actionable. Thirty-three of these patients (12.6%) received a respective targeted therapy, and the other 228 patients (87.4%) did not receive an NGS guided targeted therapy. 97 patients had EGFR copy number gains or EGFR gain of function mutations of which 21 were treated with depatuxizumab mafodotin, and one additional patient who was treated with ABBV 321. Of the NGS treatment guided therapies, depatuxizumab mafodotin was the most used targeted agent in our sample set. Additionally, there were 30 patients with fusion variants and 11 of them were FGFR3-TACC3 fusions. Of these 11, 4 received targeted regimens (36.4%) with either TAS-120, pemigatinib, erdafitinib, or erdafitinib with ponatinib. The other fusion variants were not acted upon. Conclusions: These preliminary results suggest that NGS data currently does not frequently impact treatment decisions for glioblastoma. Although this study is limited by being a single institution study, future efforts include expanding this analysis to multiple institutions. With improvements in therapeutics as well as with wider availability of NGS testing, sequencing data may impact a larger percentage of glioblastoma patients.

Controlled IL-12 in combination with a PD-1 inhibitor subjects with recurrent glioblastoma

2510

Background: Monotherapy with intratumoral Ad-RTS-hIL-12 (Ad), a gene therapeutic conditionally expressing IL-12 under the transcriptional control of oral veledimex (“Controlled IL-12”), was shown in a phase 1 study (NCT02026271) to elicit a new and sustained intra-tumoral infiltration of T cells with co-expression of PD-1. We report updated findings following completion of enrollment (with follow-up ongoing) for a phase 1 substudy (NCT03636477) evaluating safety and tolerability of local, Controlled IL-12 in combination with nivolumab (nivo) in adults with recurrent glioblastoma (rGBM). Methods: Multicenter, open label, dose-escalation phase 1 trial to evaluate safety and tolerability of local, Controlled IL-12 with nivo in adult subjects with rGBM. Ad was administered by single intratumoral injection (2 x 1011 viral particles, Day 0 at time of resection) plus V (10 or 20 mg) PO QD x 15 with nivo (1 or 3 mg/kg) IV on Days -7, 15, then Q2W. Results: 21 subjects were treated (Cohort 1: V 10 mg, nivo 1 mg/kg, n = 3; Cohort 2: V 10 mg, nivo 3 mg/kg, n = 3; and Cohort 3: V 20 mg, nivo 3 mg/kg, n = 3 + 12 expansion). Safety data were similar to Ad+V monotherapy. Adverse reactions during follow-on nivo dosing were consistent with anti-PD-1 labeling, manageable, and generally reversible with no synergistic toxicities. Focusing on the 20mg V cohort (recommended phase 2 dose), serum IL-12 mean ± SEM (screening, 0.4 ± 0.1 pg/mL; Day 0, 0.6 ± 0.1 pg/mL), increased after Ad+V to 8.7 ± 3.3 pg/mL on Day 3. Similarly, serum IFN-g levels did not increase due to nivo alone (screening, 0 ± 0 pg/mL; Day 0, 0 ± 0 pg/mL), increasing after Ad+V to 6.2 ± 2.3 pg/mL on Day 7. Additionally, nivo alone did not significantly increase circulating T cells (CD3+ CD8+%) (paired differences comparison, Day 0 to screening) 3.1%, p =0.13, whereas Ad+V significantly increased peripheral T cells (Day 28 - Day 0) 3.6%, p =0.02. Pseudoprogression followed by a decrease in size (SPD) has been shown as evidenced by serial MRIs in a subgroup of subjects. Preliminary overall survival findings will be presented. Conclusions: Controlled IL-12 with PD-1 inhibition is a rational combination with initial data consistent with immune-mediated effects, a favorable safety profile, and early evidence of anti-tumor effects. An additional phase 2 study combining Controlled IL-12 with cemiplimab-rwlc in adults with rGBM is ongoing. Clinical trial information: NCT03636477 .

Survival of subjects with recurrent glioblastoma receiving intratumoral administration of controlled IL-12 with limited exposure to dexamethasone

2564

Background: Interleukin-12 (IL-12) results in anti-tumor responses in preclinical models but requires tightly controlled production to achieve safety and elicit immune system activation to realize efficacy. A phase 1 “main study” (NCT02026271) enrolled subjects with Grade III or IV gliomas who at the time of resection received intratumoral administration of a replication-deficient adenovirus expressing IL-12 under control of a transcriptional switch (Ad-RTS-hIL-12, Ad) regulated by veledimex (V), referred to as “Controlled IL-12”. It was anticipated that dexamethasone (dex), a lymphocytotoxic corticosteroid used to control edema, might diminish response to immunotherapies. We report updated findings from a substudy of subjects who were dex-free during the 4 weeks prior to Ad administration. Methods: Multicenter, phase 1 substudy (NCT03679754) that assesses safety and tolerability of Controlled IL-12 by local injection (Day 0, time of resection) of Ad (2 x 1011 viral particles) + V (20 mg PO QD x15 doses, Days 0-14) in subjects that were bevacizumab naïve and not receiving dex 4 weeks prior to Ad. Results: 36 subjects were treated. Of the 36, a majority received low-dose corticosteroids (≤ 20 mg dex total during V) as compared with the main study (75% vs 40%). More subjects in the substudy as compared with the main study had multifocal vs. unifocal disease (39% vs 7%). The safety profile was similar for both. Adverse reactions were mild to moderate and were manageable and reversable upon withholding V. Activation of the switch in both the main study and substudy (V 20 mg; n = 51) resulted in increased mean peak values (Day 0-28) of serum IL-12 (25.8 vs. 20.4 pg/mL) and IFN-g (57.0 vs. 39.5 pg/mL). Initial median overall survival (mOS) (unifocal, ≤ 20 mg dex cumulative, n = 20) was 16.2 (8.9, 18.5) mons (mean follow-up 12.3 mons) (Neuro Oncol 2019; 21 [suppl_6]:vi5). mOS including the impact of dex and key subject characteristics from the two studies (n = 51) will be updated and tumor response data will be provided. Conclusions: Monotherapy with Controlled IL-12 resulted in sustained increase in serum recombinant IL-12 and downstream endogenous IFN-g. There is evidence of immune-mediated anti-tumor effects which is associated with increased mOS as compared with historical controls. Follow up will investigate the adverse impact of dex, as well as the effect of additional subject characteristics ( e.g., unifocal vs. multifocal disease) on mOS. Clinical trial information: NCT03679754 .

Final results of controlled IL-12 monotherapy in adults with grade III or IV gliomas

3040

Background: Interleukin-12 (IL-12), a master regulator of the immune system, results in anti-tumor responses in preclinical models, but safe use requires tightly controlled production. This phase 1 trial (NCT02026271) is the first to evaluate the safety and tolerability of Ad-RTS-hIL-12 (Ad) under transcriptional control with veledimex (V) in adults with grade III or IV gliomas. Methods: Multicenter, phase 1, open-label, 3 + 3 dose escalation study of Ad (a single intratumoral injection, 2 × 1011 viral particles, Day 0) with oral V dosing (Days 0 to 14) of 10, 20, 30, and 40 mg in subjects with rGBM. Results: 38 subjects were treated (resection group: V 10 mg (n = 6); 20 mg (n = 15); 30 mg (n = 4); 40 mg (n = 6); and, stereotactic group: V 20 mg, n = 7). The adverse event profile of Ad+ V, was predictable and controllable, with the main adverse reactions (ARs) being mild to moderate. All ARs were manageable and reversible upon withholding V. We observed increased peak (mean ± SEM) serum recombinant IL-12 and downstream endogenous IFN-g: V 10mg 21.4 ± 11.7 pg/mL and 14.6 ± 7.1 pg/mL; V 20 mg 25.8 ± 7.1 pg/mL and 57.0 ± 26.5 pg/mL; V 30 mg 65.7 ± 45.5 pg/mL and 60.7 ± 50.0 pg/mL; V 40mg 108.8 ± 41.0 pg/mL and 167.5 ± 70.9 pg/mL, V 20mg (stereotactic) 25.1 ± 7.2 pg/mL and 69.8 ± 48.5 pg/mL, respectively. In the V 20 mg cohort , there was an increase in tumor-associated T cells (CD3+CD8+%) from pre-Ad (mean ± SEM) 0.6 ± 0.4 to biopsy (~5 mons) 6.3 ± 5.0 and production of IFN-g 97.2 ± 85.3 pg/g (n = 2). Median overall survival (mOS) in the V 20 mg cohort (resection, n = 15) was 12.7 mons (mean follow-up, 13.1 mons). Subjects with unifocal disease (n = 6) who received low-dose (≤ 20mg total) dexamethasone during active dosing (Days 0-14) had an mOS of 17.8 mons. Tumor response data will be presented. Conclusions: Results of Controlled IL-12 in rGBM are promising, with V-dependent and proportional increases in IL-12 and IFN-g resulting in immune activation, with a favorable safety profile and encouraging survival. The 20 mg V dose is the recommended phase 2 dose. Controlled IL-12 is being evaluated in a monotherapy substudy (n = 36, V 20 mg) and two combination studies with immune checkpoint inhibitors for rGBM. Clinical trial information: NCT02026271 .

Post-marketing safety surveillance of tumor treating fields (TTFields) in patients with high-grade glioma in clinical practice

2542

Background: Tumor Treating Fields (TTFields) are an antineoplastic treatment delivering low intensity, intermediate frequency, alternating electric fields through two pairs of transducer arrays locoregionally applied to tumor bed. TTFields are FDA-approved for glioblastoma (GBM; 200 kHz) and mesothelioma (150 kHz). Safety and effectiveness were demonstrated in the phase III EF-11 and EF-14 trials in recurrent GBM (rGBM) and in newly diagnosed GBM (ndGBM), respectively. The main TTFields-related adverse event (AE) was array-associated manageable skin irritation. We report AEs from TTFields-treated patients in the real-world, clinical practice setting. Methods: Unsolicited, global, post-market surveillance data from TTFields-treated patients (October 2011–February 2019) were retrospectively analyzed using MedDRA v21.1, stratified by region (US, EMEA [Europe, Middle East, Africa], or Japan), diagnosis (ndGBM, rGBM, anaplastic astrocytoma and anaplastic oligodendroglioma, or other brain tumors that includes brain metastases from different cancer types), and years of age (<18, pediatric; 18 to 64, adults; or ≥65, elderly). Results: Of 11,029 patients, 53% had ndGBM, 39% had rGBM (at any line of recurrence), 6% had anaplastic astrocytoma/oligodendroglioma, and 1% had other brain tumors. Most were adults (73%) and 26% were elderly (≥65 years of age). The majority of patients were males (66.3%) compared to females (33.7%), with a ratio representative of a typical GBM population. The most reported TTFields-related AE was array-associated local skin reaction, with an incidence of 38% in ndGBM, 29% in rGBM, 38% in anaplastic astrocytoma/oligodendroglioma, 31% in other brain tumors, 37% in pediatric, 34% in adults, and 36% in elderly patients. Most skin AEs were mild to moderate and resolved with no treatment or over the counter topical ointments. Incidence of other TTFields-related AEs in patients with ndGBM and rGBM, respectively, included heat sensation (under-array warmth; 11%, 10%), electric sensation (under-array tingling; 11%, 9%), and headache (7%, 6%). Conclusions: This retrospective, global, TTFields safety surveillance analysis revealed no new safety signals, with favorable safety and tolerability comparable to published TTFields/GBM trials. The most common TTFields-related AE was array-associated local skin reaction. The safety profile remained consistent among subgroups (diagnosis, age, or region) and total cohort, indicating feasibility in multiple subpopulations, including elderly patients.

A phase II trial of bevacizumab in patients with recurrent solid tumor brain metastases who have failed whole brain radiation therapy (WBRT)

2070

Background: Brain metastases (BM) are the most common intracranial malignancy with overall a poor prognosis estimated at approximately 4 months from time of initial diagnosis for treated patients, and even lower after failing WBRT after which treatment options have been limited and outcomes poor. Methods: This is an open label phase 2 study where patients who have previously failed WBRT received bevacizumab at a dose of 10 mg/kg intravenously every two weeks until CNS disease progression with one cycle being defined as 4 weeks. The primary endpoint was objective radiographic tumor response as defined by modified Response Assessment in Neuro-oncology (RANO) criteria. Secondary endpoints included progression free survival (PFS) at 6 months, time to progression, time to response, duration of response, overall survival (OS), quality of life (QOL) as measured by the FACT-G and FACT-Br and safety. Results: A total of 27 patients were consented and registered to study of which 24 were evaluable for ORR (3 came off study prior to first follow up MRI brain). Medianage was 53 (range 27-73), median number of cycles was 5.5 (range 1-20) with a median follow up of 8.7 months (range 2.4-47.9mo). Of the 24evaluable patients, there were 6 Partial response, 16 stable disease and 2progressive disease. The 6 month PFS: 46% (95% CI: 25% - 67%) and median PFS was 5.3 months. Median OS was 9.5 months (95% confidence interval 6.3m – 15.0m). For the patients who completed sequential QOL assessments, there was no significant decline in QOL but there was a nonsignificant improvement in the FACT-Br scores. Overall, treatment was well tolerated with 3grade 3 adverse events seen: hypertension (n = 3), headache (n = 1) and thrombotic event (n = 1). Conclusions: For this WBRT failure BM population, we were able to show a 25% disease response to bevacizumab therapy along with good drug tolerability and no noted central nervous system bleeding. Improved survival as compared to historical controls was seen 9.5 m. Of the 24 evaluable patients, 81% (22/24) experienced clinical benefit defined as stable disease or better. Bevacizumab therapy could be a viable option for solid tumor BM patients who experience progression following WBRT, however a larger trial is required to confirm this data. Clinical trial information: NCT01898130.

Evaluation of controlled IL-12 in combination with a PD-1 inhibitor in subjects with recurrent glioblastoma

2020

Background: Ad-RTS-hIL-12 (Ad) is a novel gene therapy candidate conditionally expressing IL-12 under the control of veledimex (V) acting via the proprietary RheoSwitch Therapeutic System (RTS) gene switch with a therapeutic window. Intratumoral Ad + oral V monotherapy (Phase 1 study, NCT02026271 ) resulted in a new sustained intra-tumor influx of activated cytotoxic T cells, consistent with an immune-mediated anti-tumor effect improving median overall survival (mOS) of subjects with recurrent glioblastoma (rGBM). This correlated with an increased circulating CD8+/FoxP3+ T cell ratio (“cytoindex”), an emerging biomarker for mOS. PD-1 expression on infiltrating T cells at biopsy after Ad+V, supports combining controlled IL-12 with a PD-1 inhibitor to further augment T-cell-mediated anti-tumor effects. The rationale is also supported by increased OS (100% combo vs 63% for Ad+V vs 40% for anti-PD-1) in mice bearing GL-261 glioma. Methods: An ongoing open label, dose-escalation Phase 1 trial (NCT03636477) is evaluating safety and tolerability of local, controlled IL-12 with nivolumab (nivo) in adult subjects with rGBM. Ad was administered by single intratumoral injection (2 x 1011 viral particles, Day 0) plus V (10-20 mg) PO QD x 15 with nivo (1-3mg/kg) IV on Days -7, 15, then Q2W. Results: Safety data revealed a similar profile as Ad +V monotherapy. Adverse reactions (ARs) during follow-on nivo dosing were consistent with anti-PD-1 reports. ARs were manageable and reversible with no synergistic toxicities. Nivo alone did not alter peripheral IL-12 levels (median baseline (before anti-PD-1) 0.9 pg/mL; Day 0 1 pg/mL) increasing to 5.5 pg/mL on Day 3. Nivo alone increased peripheral T cells (CD3+CD8+ median baseline 23%; Day 0 26%) and Ad+V elevated peripheral CD3+CD8+ to 31% at Day 14. Nivo alone decreased regulatory T cells (FoxP3 baseline 1.5% vs Day 0 0.8%). Ad+V decreased these to 0.3% (Day 14). Combination therapy improved the cytoindex (baseline 15; Day 0 29; Day 14 80). Conclusions: Controlled IL-12 production using Ad + V with nivo is a rational combination with initial data consistent with immune-mediated anti-tumor effects with a favorable safety profile, warranting continued investigation in rGBM. Clinical trial information: NCT03636477.

Evaluation of controlled IL-12 as monotherapy in subjects with recurrent GBM

2053

Background: Interleukin-12 (IL-12), a master regulator of the immune system, results in anti-tumor responses in preclinical models, but safe use requires tightly controlled production. It was conditionally produced in Ph1 “main” study (NCT02026271) in subjects with recurrent glioblastoma (rGBM) using a replication-incompetent adenovirus modified to express IL-12 under transcriptional control of the proprietary RheoSwitch Therapeutic System (Ad-RTS-hIL-12, Ad) regulated by dose of veledimex (V). Monotherapy resulted in sustained intra-tumor influx of activated cytotoxic T cells, consistent with immune-mediated anti-tumor effect, improving overall survival (OS). This correlated with increased circulating CD8+/FoxP3+ T-cell ratio (“cytoindex”), an emerging biomarker of OS. While widely used with neurosurgery, dexamethasone (dex) blunts response to immunotherapies, nevertheless median mOS of subjects who received 20mg V of 12.7 mo (n=15) at 13.1 mo follow-up. However, subanalysis (n=6) showed low-dose dex (total ≤20 mg) during V dosing improved mOS (17.8 mo). We report a 36 subject substudy in rGBM with limited dex, total rGBM treated (n=70+). Methods: Ongoing Phase 1 substudy (NCT03679754) assesses safety and tolerability of local, inducible IL-12 by single intratumoral injection of Ad (2 x 1011 viral particles) + V (20 mg PO QD x15 doses Days 0-14) in subjects not receiving dex 4 wks prior to Ad. Results: As of 03Jan19, the majority of new subjects received low-dose dex (total ≤20mg Days 0-14). The initial impact of dex on mOS will be reported. As in the main study, Ad+V 20 mg respectively increased (median) serum IL-12 and downstream IFN-g from Days 0-3: 0.8 to 8.8 pg/mL and 0 to 8.6 pg/mL. Between Days 0-14, there was net increase in cytoindex (from 20 to 46). The safety profile was similar to the main study with the main adverse reaction (AR) being mild to moderate cytokine release syndrome (CRS) characterized by flu-like symptoms. No grade 4 CRS was noted; all ARs were manageable and reversable upon holding V. Conclusions: Local, controlled IL-12 production using the Ad + V platform in subjects with rGBM safely activates the immune system and when dex is limited, appears to further improve mOS, which warrants continued investigation. Clinical trial information: NCT03679754.

A phase 0 first-in-human study using NU-0129: A gold base spherical nucleic acid (SNA) nanoconjugate targeting BCL2L12 in recurrent glioblastoma patients

3012

Background: Glioblastoma is a difficult to treat tumor with therapeutics limited by their ability to cross the blood brain barrier. SNAs, i.e., gold nanoparticle cores covalently conjugated with a corona of densely packed, highly oriented siRNA oligonucleotides targeted to the GBM oncogene BCL2L12, represent a novel class of blood-brain and blood-tumor barrier-permeable nanomedicinal conjugates, for suppressing gene expression in the tumors of GBM patients. Methods: This is a single-arm, open-label, “window of opportunity” phase 0 first-in-human trial to determine the safety and bioavailability of a novel nanotherapeutic compound, NU-0129. Enrolled patients were treated with intravenous NU-0129 at the dose of 0.04mg/kg. This treatment dosing was considered microdosing defined as 1/50ththe NOAEL (no observed adverse event level) from non-human primate studies. Treatment was followed by tumor resection 8-48 hours later. Primary outcome patient safety and toxicity was monitored weekly for 3 weeks post-infusion. Secondary objectives included biodistribution of NU0129 in tissue, evaluation of pharmacokinetics of NU0129 and the feasibility of NU0129 administration. Exploratory objectives included Bcl2L12 expression and post treatment apoptotic markers as well as progression free survival and overall survival rates. Results: 8 patients were enrolled, treated and subsequently underwent surgical resection. No significant treatment related toxicities were seen. Severe ( > grade 3) adverse events were observed in two patients: hypophosphatemia (one grade 3, one grade 4) and one patient with grade 3 lymphopenia, all were considered as “possibly related” by treating oncologists. In 6 of the 8 patients sufficient tumor tissue was available for analysis of gold accumulation by ICP-MS (inductively coupled plasma-mass spectrometry), and gold accumulation was seen in the tumor tissue of all 6 of these patients. Conclusions: Macrodosing of the nanotherapeutic NU-0129 was well tolerated in glioblastoma patients with no unexpected adverse effects and showed initial evidence of crossing blood brain barrier. Immunohistochemistry for Bcl2L12 expression, apoptotic markers, and PK studies are pending. The demonstration of gold nanoparticles in the tumor tissue validates this approach for drug delivery. Clinical trial information: NCT03020017.

Initial phase 1 study of WT2725 dosing emulsion in patients with advanced malignancies

2066

Background: WT2725 is a Wilms’ tumor (WT1)-derived-oligopeptide vaccine intended to induce WT1 specific cytotoxic T-lymphocytes against WT1 positive tumors in HLA-A*0201+ or HLA-A*0206+. This first in human study of WT2725 was conducted to evaluate the safety, tolerability, and efficacy. Methods: Subjects with progressive or recurrent glioblastoma (GBM), acute myeloid leukemia (AML) (patients in morphologic remission with minimal residual disease determined by WT1 RT-PCR were allowed), non-small cell lung cancer (NSCLC), or ovarian cancer despite standard therapy were treated with 0.3, 0.9, 3, and 9 mg of WT2725 subcutaneously (s.c.) every week for 4 weeks, then every other week for 6 weeks, and every 4 weeks thereafter until progression or other discontinuation event (part 1); and with 18 mg and 27 mg of WT2725 s.c. every week for 8 weeks, then every other week for 10 weeks, and every 4 weeks thereafter until progression or other discontinuation event (part 2). Responses were evaluated by Immune-related Response Criteria (irRC) for solid tumors and modified International Working Group (IWG) for AML. Results: 62 subjects were dosed, the most frequent adverse events were grade 1 injection site reactions (no grade 3 injection site reactions or dose limiting toxicities observed). Of the 21 GBM subjects who were dosed, seven survived for ≥ 1 year (33%). Of these seven subjects, three survived for ≥18 months (14%), and two for ≥2 years (both in complete radiologic remission, 9.5%). One of the seven subjects with ≥1 year survival had previous treatment with bevacizumab. Two subjects continue dosing (1 complete response with no measurable disease >3 years and 1 partial response > 13 months on study). Results in subjects with non-GBM tumors (12 subjects with AML, 21 with ovarian CA, 7 with NSCLC, and 1 other cancer) are not presented here. WT1-specific CTLs and tumor burden was monitored. WT1 specific CTLs were associated with decrease of tumor burden in two patients with low tumor burden. Some patients with high disease burden did not respond. Conclusions: Preliminary data suggests WT2725 is well tolerated with potential antitumor activity in GBM patients, supporting future development of WT2725 for treatment of GBM in selected subjects. Clinical trial information: NCT01621542.

Expanded phase I study of intratumoral Ad-RTS-hIL-12 plus oral veledimex: Tolerability and survival in recurrent glioblastoma

2044

Background: Glioblastoma (GBM) is an aggressive brain tumor affecting ~74,000 people worldwide annually. Recurrent GBM patients have a median OS (mOS) of 6-7 months. OS in patients who have failed temozolomide, bevacizumab or equivalent salvage chemotherapy, is ~3-5 months. New therapies are urgently needed. Ad-RTS-hIL-12 (Ad) is a novel gene therapy expressing IL-12 under the control of an oral activator ligand, veledimex (V), through the RheoSwitch Therapeutic System. Intratumoral administration of Ad results in targeted tumor cytotoxicity and induction of systemic T cell memory. Ad + V is a treatment strategy to extend the IL-12 therapeutic window. Methods: In a multicenter Phase I dose escalation trial and expansion cohort, subjects with recurrent or progressive Grade III or IV glioma undergoing resection were injected intratumorally with Ad 2 x 1011 viral particles and daily oral V for 15 doses, beginning prior to surgery. The primary endpoint is safety and tolerability of Ad + V; secondary endpoints include OS. Results: 25 subjects were dosed in 3 dose escalation cohorts: 20 mg (n = 7), 30 mg (n = 4), and 40 mg (n = 6) and an expansion cohort of 20 mg (n = 8). Results show V crossed the blood brain-barrier with 35±5% of plasma levels detected in the brain tumor. The 20 mg dose (n = 15) had better drug compliance (86%) than the 30 mg (63%) or 40 mg (52%) cohorts and the 20 mg cohort shows better survival (mOS 12.7 months) compared to other cohorts. The frequency of related ≥Grade (G)3 AEs in the 20 mg cohort was significantly lower: 20% in 20mg, 50% in 30mg and 40 mg. In the 20 mg cohort, the most frequent AEs were transient mild flu-like symptoms seen in 12/15, G3 cytokine release syndrome in 2/15, G3 elevated ALT/AST in 1/15 and G3 lymphopenia in 3/15. All AEs reversed promptly upon discontinuing V. Conclusions: Overall, Ad + 20 mg V is well tolerated; toxicities were predictable and reversible upon discontinuing V. There is a correlation between V dose, BBB penetration and drug related AEs. The tolerability and encouraging survival observed to date warrant further investigation in a pivotal trial. A stereotactic arm and a pediatric trial in diffuse intrinsic pontine glioma patients are planned. Clinical trial information: NCT02026271.

Leptomeningeal carcinomatosis in esophageal cancer: a case series and systematic review of the literature

The aim of this study was to more clearly define the clinical course of leptomeningeal carcinomatosis due to esophageal cancer. A single institution retrospective case series was conducted. Additionally, a systematic review of the literature was performed. We present a large case series (n = 7) of leptomeningeal carcinomatosis due to esophageal cancer. Our case series and systematic review of the literature report similar findings. In our series, we report a predominance of male patients (86%) with adenocarcinoma histology (77%). Variable onset of leptomeningeal involvement of esophageal cancer in relation to the original diagnosis of the primary disease (5 months to 3 years and 11 weeks) was noted. Disease progresses quickly and overall survival is poor, measured in weeks (2.5-16 weeks) from the diagnosis of leptomeningeal involvement. Four of our patients initiated whole-brain radiation therapy with only two completing the course prior to clinical deterioration. Our patient with the longest survival (16 weeks) received intrathecal topotecan and oral temozolomide. Leptomeningeal carcinomatosis secondary to esophageal cancer has a poor prognosis. A clearly beneficial treatment modality is lacking.

Final results of a single-arm phase II study of bevacizumab and temozolomide following radiochemotherapy in newly dignosed adult glioblastoma patients

2076

Background: This study evaluated efficacy and safety of bevacizumab (BEV) added to the post-radiation treatment phase for patients with newly diagnosed glioblastoma (GBM). Methods: Sixty-two participants with newly diagnosed GBM were enrolled between May 2007 and June 2010. Participants received standard radiation therapy (RT) within 6 weeks of surgery, and concomitant administration of temozolomide (TMZ). Four weeks after radiation, treatment with TMZ (Days 1-5 of a 28 day cycle) with BEV, (days 1 and 15 of a 28 day cycle) was started, and continued until disease progressed or adverse effects indicated need to stop treatment. Analyses were completed for all participants by intention to treat (ITT), with progression-free survival (PFS) and overall survival (OS) serving as primary and secondary endpoints respectively. Results: Subbjects completed a mean of 7.7 (range 0-29) cycles of post-RT with BEV and TMZ. Twenty participants (32%) were unable to proceed to the post-RT phase. The forty-two participants who did proceed to the post-RT phase completed a mean of 11.5 cycles of treatment. Thirty-eight participants (61%) stopped the study due to disease progression; 6 participants (14%) voluntarily discontinued treatment after 24 cycles with at least stable disease. At a median follow-up time of 24 months, median progression-free survival (PFS) for all participants was 8.8 months while median overall survival (OS) was 16.5 months for all participants. Ly with These results also compare favorably with recently reported results from the AVAglio study (PFS = 10.6 mo.). The toxicity profile was consistent with that reported in similar studies. MGMT promoter methtion.ylation status is under investiga Conclusions: Participants in this study demonstrated a median 1.9 month PFS benefit as compared to the 6.9 median OS reported by Stupp, et al. (2005) and a median 1.9 month OS benefit as compared to the 14.6 month median OS reported by Stupp, et al. (2005). Results suggest that the addition of bevacizumab to the post-RT phase of treatment improves both PFS and OS for persons with GBM despite the high percentage of participants being unable to progress to post-radiation treatment. Clinical trial information: NCT005906.