ILUSTRO: Phase II Multicohort Trial of Zolbetuximab in Patients with Advanced or Metastatic Claudin 18.2-Positive Gastric or Gastroesophageal Junction Adenocarcinoma

PURPOSE

Zolbetuximab, an IgG1 monoclonal antibody, binds to claudin 18.2 (CLDN18.2) and mediates tumor cell death through antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. We sought to examine zolbetuximab combinations in CLDN18.2-positive HER2-negative gastric/gastroesophageal junction (G/GEJ) adenocarcinoma.

PATIENTS AND METHODS

This phase II study assessed efficacy and safety of zolbetuximab, alone or with modified FOLFOX6 (mFOLFOX6) or pembrolizumab, in CLDN18.2-positive advanced/metastatic G/GEJ adenocarcinoma. Patients received zolbetuximab as monotherapy in third/later-line (Cohort 1A, n = 30), with mFOLFOX6 in first-line (Cohort 2, n = 21), or with pembrolizumab in third/later-line (Cohort 3A, n = 3) treatment. The primary endpoint for Cohort 1A was objective response rate (ORR). Key secondary endpoints were ORR (Cohorts 2 and 3A), overall survival (OS; Cohort 1A), and progression-free survival (PFS) and safety (all cohorts).

RESULTS

ORR was 0% in Cohorts 1A and 3A, and 71.4% [95% confidence interval (CI), 47.82-88.72] in Cohort 2. Median PFS was 1.54 months (95% CI, 1.31-2.56) in Cohort 1A, 2.96 months (95% CI, 1.48-4.44) in Cohort 3A, and 17.8 months (95% CI, 8.05-25.69) in Cohort 2. Median OS in Cohort 1A was 5.62 months (95% CI, 2.27-11.53). Gastrointestinal adverse events occurred across cohorts [nausea, 63%-90% (grade ≥ 3, 4.8%-6.7%) and vomiting, 33%-67% (grade ≥ 3, 6.7%-9.5%)].

CONCLUSIONS

Zolbetuximab plus mFOLFOX6 demonstrated promising efficacy in previously untreated patients with CLDN18.2-positive G/GEJ adenocarcinoma. These data support the first-line development of zolbetuximab in patients whose tumors are CLDN18.2-positive. Across cohorts, zolbetuximab treatment was tolerable with no new safety signals.

A phase I/II study of intrathecal trastuzumab in human epidermal growth factor receptor 2-positive (HER2-positive) cancer with leptomeningeal metastases: Safety, efficacy, and cerebrospinal fluid pharmacokinetics

BACKGROUND

Patients with human epidermal growth factor receptor 2-positive (HER2-positive) cancers have a high incidence of central nervous system (CNS) spread, but unfortunately systemic trastuzumab which targets the HER2 receptor has little CNS penetration. The purpose of this study was to determine the maximum-tolerated dose of intrathecal trastuzumab and its efficacy in patients with HER2-positive leptomeningeal disease (LMD).

METHODS

This multicenter study enrolled 34 LMD patients in a combined phase I/II study in treating patients with intrathecal trastuzumab. Any HER2-positive histology was allowed in the phase I; the phase II was limited to HER2-positive breast cancer.

RESULTS

Intrathecal trastuzumab was well-tolerated, with one dose limiting toxicity of grade 4 (arachnoiditis) occurring at the 80 mg twice weekly dose. The recommended phase II dose was 80 mg intrathecally twice weekly. Twenty-six patients at dose level 80 mg were included in evaluation for efficacy: partial response was seen in 5 (19.2%) patients, stable disease was observed in 13 (50.0%), and 8 (30.8%) of the patients had progressive disease. Median overall survival (OS) for phase II dose treated patients was 8.3 months (95% CI 5.2-19.6). The phase II HER2-positive breast cancer patients median OS was 10.5 months (95% CI 5.2-20.9). Pharmacokinetic (PK) studies were limited in the setting of concurrent systemic trastuzumab administration, however, did show stable cerebrospinal fluid (CSF) concentrations with repeated dosing suggest that trastuzumab does not accumulate in the CSF in toxic concentrations.

CONCLUSION

This study suggests promise for potentially improved outcomes of HER-positive LMD patients when treated with intrathecal trastuzumab while remaining safe and well-tolerated for patients.

NRG Oncology/RTOG1205: A Randomized Phase II Trial of Concurrent Bevacizumab and Reirradiation Versus Bevacizumab Alone as Treatment for Recurrent Glioblastoma

PURPOSE

To assess whether reirradiation (re-RT) and concurrent bevacizumab (BEV) improve overall survival (OS) and/or progression-free survival (PFS), compared with BEV alone in recurrent glioblastoma (GBM). The primary objective was OS, and secondary objectives included PFS, response rate, and treatment adverse events (AEs) including delayed CNS toxicities.

METHODS

NRG Oncology/RTOG1205 is a prospective, phase II, randomized trial of re-RT and BEV versus BEV alone. Stratification factors included age, resection, and Karnofsky performance status (KPS). Patients with recurrent GBM with imaging evidence of tumor progression ≥ 6 months from completion of prior chemo-RT were eligible. Patients were randomly assigned 1:1 to re-RT, 35 Gy in 10 fractions, with concurrent BEV IV 10 mg/kg once in every 2 weeks or BEV alone until progression.

RESULTS

From December 2012 to April 2016, 182 patients were randomly assigned, of whom 170 were eligible. Patient characteristics were well balanced between arms. The median follow-up for censored patients was 12.8 months. There was no improvement in OS for BEV + RT, hazard ratio, 0.98; 80% CI, 0.79 to 1.23; P = .46; the median survival time was 10.1 versus 9.7 months for BEV + RT versus BEV alone. The median PFS for BEV + RT was 7.1 versus 3.8 months for BEV, hazard ratio, 0.73; 95% CI, 0.53 to 1.0; P = .05. The 6-month PFS rate improved from 29.1% (95% CI, 19.1 to 39.1) for BEV to 54.3% (95% CI, 43.5 to 65.1) for BEV + RT, P = .001. Treatment was well tolerated. There were a 5% rate of acute grade 3+ treatment-related AEs and no delayed high-grade AEs. Most patients died of recurrent GBM.

CONCLUSION

To our knowledge, NRG Oncology/RTOG1205 is the first prospective, randomized multi-institutional study to evaluate the safety and efficacy of re-RT in recurrent GBM using modern RT techniques. Overall, re-RT was shown to be safe and well tolerated. BEV + RT demonstrated a clinically meaningful improvement in PFS, specifically the 6-month PFS rate but no difference in OS.

Infigratinib in Patients with Recurrent Gliomas and FGFR Alterations: A Multicenter Phase II Study

PURPOSE

FGFR genomic alterations (amplification, mutations, and/or fusions) occur in ∼8% of gliomas, particularly FGFR1 and FGFR3. We conducted a multicenter open-label, single-arm, phase II study of a selective FGFR1-3 inhibitor, infigratinib (BGJ398), in patients with FGFR-altered recurrent gliomas.

PATIENTS AND METHODS

Adults with recurrent/progressive gliomas harboring FGFR alterations received oral infigratinib 125 mg on days 1 to 21 of 28-day cycles. The primary endpoint was investigator-assessed 6-month progression-free survival (PFS) rate by Response Assessment in Neuro-Oncology criteria. Comprehensive genomic profiling was performed on available pretreatment archival tissue to explore additional molecular correlations with efficacy.

RESULTS

Among 26 patients, the 6-month PFS rate was 16.0% [95% confidence interval (CI), 5.0-32.5], median PFS was 1.7 months (95% CI, 1.1-2.8), and objective response rate was 3.8%. However, 4 patients had durable disease control lasting longer than 1 year. Among these, 3 had tumors harboring activating point mutations at analogous positions of FGFR1 (K656E; n = 2) or FGFR3 (K650E; n = 1) in pretreatment tissue; an FGFR3-TACC3 fusion was detected in the other. Hyperphosphatemia was the most frequently reported treatment-related adverse event (all-grade, 76.9%; grade 3, 3.8%) and is a known on-target toxicity of FGFR inhibitors.

CONCLUSIONS

FGFR inhibitor monotherapy with infigratinib had limited efficacy in a population of patients with recurrent gliomas and different FGFR genetic alterations, but durable disease control lasting more than 1 year was observed in patients with tumors harboring FGFR1 or FGFR3 point mutations or FGFR3-TACC3 fusions. A follow-up study with refined biomarker inclusion criteria and centralized FGFR testing is warranted.

Zolbetuximab + CAPOX versus CAPOX in first-line treatment of claudin18.2+/HER2– advanced/metastatic gastric or gastroesophageal junction adenocarcinoma: GLOW phase 3 study

TPS365

Background: Despite standard treatment options (eg, CAPOX, capecitabine + oxaliplatin), 5-year survival with advanced/metastatic gastric or gastroesophageal junction adenocarcinoma (G/GEJ) is poor and limited biomarkers exist to inform treatment selection. Claudin 18.2 (CLDN18.2), a targetable biomarker, is a tight junction protein that is normally confined to gastric mucosa of healthy tissue and is often retained in G/GEJ. Zolbetuximab, a chimeric IgG1 monoclonal antibody, binds to CLDN18.2 and mediates cell death through antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Phase 2 (FAST; Sahin, Ann Oncol. 2021) results showed prolonged survival with zolbetuximab + EOX (epirubicin, oxaliplatin, capecitabine) vs EOX in CLDN18.2+ advanced G/GEJ. Preliminary phase 2 (NCT03505320, ILUSTRO Cohort 2; Klempner, J Clin Oncol. 2021) results showed promising antitumor activity with combination zolbetuximab + mFOLFOX6 (5-fluorouracil, folinic acid, oxaliplatin) in CLDN18.2+ advanced G/GEJ. Methods: GLOW (NCT03653507) is enrolling ̃500 adults from global sites. Patients are required to have radiologically evaluable (RECIST v1.1) CLDN18.2+/HER2– locally advanced unresectable or metastatic G/GEJ. Prior chemotherapy for advanced/metastatic G/GEJ is not permitted. Patients will be randomized 1:1 to zolbetuximab + CAPOX or placebo + CAPOX. Randomization will be stratified by region (Asia vs non-Asia), number of metastatic sites (0 to 2 vs ≥3), and prior gastrectomy (yes vs no). Zolbetuximab will be administered at 800 mg/m2 IV on Cycle 1 Day 1 (loading dose), then at 600 mg/m2 IV every 3 weeks; 8 cycles of CAPOX will be administered. Central testing of tumor tissue will determine CLDN18.2 status; tumors will be considered CLDN18.2+ if ≥75% of tumor cells show moderate to strong membranous immunohistochemical staining. Primary endpoint: progression-free survival per independent review. Secondary endpoints: overall survival; objective response rate; duration of response; safety/tolerability, pharmacokinetics, and immunogenicity of zolbetuximab. As of September 22, 2021, 135 sites were open for screening and enrollment. Clinical trial information: NCT03653507.

A multi-institutional phase II trial of bevacizumab for recurrent and refractory meningioma

Background

Systemic therapies for refractory meningiomas are limited with no FDA-approved therapeutics. Vascular endothelial growth factor (VEGF) is a signaling protein associated with neovascularization, peritumoral edema, and meningioma tumorigenesis.

Methods

This phase II study investigates the efficacy of bevacizumab (BEV), a VEGF binding monoclonal antibody, in patients with progressive Grade I (G1M), Grade II (G2M), Grade III (G3M) meningioma, and other non-parenchymal tumors including vestibular schwannoma (n = 4) and hemangiopericytoma (n = 4) with the primary endpoint of progression-free survival rate at 6-months (PFS-6). Non-meningiomas were included with the respective meningioma grade in the analysis. Secondary endpoints include median overall survival (mOS) and response rate.

Results

Fifty Patients (26 women; median age 54 years; range 23-81), 42 with progressive meningioma were treated: 10 G1M, 20 G2M, and 12 G3M. Prior treatments include surgical resection (41 patients), radiosurgery (24 patients), external beam radiotherapy (28 patients), and chemotherapy (14 patients). Median infusions administered were 16 (range, 2-68). Response was graded using the Macdonald's criteria. PFS-6, median PFS, and mOS were 87%, 22 months, 35 months for G1M; 77%, 23 months, 41 months for G2M; and 46%, 8 months, 12 months for G3M. Best radiographic responses include stable disease (G1M: 100%; G2M: 85%; G3M: 82%); partial response (G1M: 0%; G2M: 5%; G3M: 0%) and progressive disease (G1M: 0%; G2M: 10%; G3M:18%). The most common toxicities were hypertension (n = 19, 42.2%), proteinuria (n = 16, 35.6%), and fatigue (n = 14, 31.1%).

Conclusion

This study showed BEV is well tolerated and appears to be a promising systemic treatment option for patients with recurrent and refractory meningiomas.

Phase 2 study of zolbetuximab plus mFOLFOX6 in claudin 18.2-positive locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma (G/GEJ): ILUSTRO cohort 2

e16063

Background: One accepted treatment for patients (pts) with advanced HER2-negative G/GEJ is mFOLFOX6 (5-FU, folinic acid, oxaliplatin). Despite treatment options, 5-year survival is poor, and limited biomarkers exist to inform treatment selection. Claudin 18.2 (CLDN18.2), a tight junction protein normally confined to gastric mucosa of healthy tissue, is often retained in G/GEJ. Zolbetuximab, a chimeric IgG1 monoclonal antibody, binds to CLDN18.2 and mediates cancer cell death via antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Nonclinical results showed that cytotoxic chemotherapy increased CLDN18.2 expression, improving ADCC/CDC activity of zolbetuximab. Phase 2 results (NCT01630083, FAST) showed prolonged survival with zolbetuximab+EOX (epirubicin, oxaliplatin, capecitabine) vs EOX in G/GEJ. This study assessed antitumor activity and safety/tolerability of first-line zolbetuximab+mFOLFOX6 (Cohort 2 in NCT03505320) in G/GEJ with high CLDN18.2 expression. Methods: Cohort 2 of this multicohort study enrolled adult pts with metastatic or locally advanced unresectable G/GEJ. Patients had measurable disease (RECIST v1.1), HER2-negative disease, and high CLDN18.2 expression (≥75% of tumor cells demonstrating moderate-to-strong membranous staining by central IHC testing). Patients received zolbetuximab 800 mg/m2 IV on Cycle 1 Day 3 then 600 mg/m2 Q3W. Zolbetuximab and mFOLFOX (Q2W from Cycle 1 Day 1) were administered in 42-day cycles. Key endpoints were safety/tolerability and objective response rate by independent central review (ORRICR RECIST v1.1). Results: As of Jan 26, 2021, Cohort 2 had enrolled 21 pts; median age was 63 years (range, 36-74), 57% were male, 43% were Asian, and 38% were white. Of 19 evaluable pts, 12 had confirmed partial responses; ORRICR was 63.2% (95% CI: 38.4-83.7) (Table). Median PFS was 13.7 months (95% CI: 7.4-not estimable); 12-month PFS rate was 58%. Common adverse events (AEs) were nausea (90.5%; grade 3, 4.8%) and vomiting (61.9%; grade 3, 9.5%). Common grade 3/4 AEs were decreased neutrophil count (33.3%) and neutropenia (28.6%). There were no fatal AEs. Conclusions: Results suggest promising antitumor activity with zolbetuximab+mFOLFOX6 in metastatic or locally advanced G/GEJ. The safety profile was manageable and no new safety signals were identified. Clinical trial information: NCT03505320. [Table: see text]

CODEL: phase III study of RT, RT + TMZ, or TMZ for newly diagnosed 1p/19q codeleted oligodendroglioma. Analysis from the initial study design

BACKGROUND

We report the analysis involving patients treated on the initial CODEL design.

METHODS

Adults (>18) with newly diagnosed 1p/19q World Health Organization (WHO) grade III oligodendroglioma were randomized to radiotherapy (RT; 5940 centigray ) alone (arm A); RT with concomitant and adjuvant temozolomide (TMZ) (arm B); or TMZ alone (arm C). Primary endpoint was overall survival (OS), arm A versus B. Secondary comparisons were performed for OS and progression-free survival (PFS), comparing pooled RT arms versus TMZ-alone arm.

RESULTS

Thirty-six patients were randomized equally. At median follow-up of 7.5 years, 83.3% (10/12) TMZ-alone patients progressed, versus 37.5% (9/24) on the RT arms. PFS was significantly shorter in TMZ-alone patients compared with RT patients (hazard ratio [HR] = 3.12; 95% CI: 1.26, 7.69; P = 0.014). Death from disease progression occurred in 3/12 (25%) of TMZ-alone patients and 4/24 (16.7%) on the RT arms. OS did not statistically differ between arms (comparison underpowered). After adjustment for isocitrate dehydrogenase (IDH) status (mutated/wildtype) in a Cox regression model utilizing IDH and RT treatment status as covariables (arm C vs pooled arms A + B), PFS remained shorter for patients not receiving RT (HR = 3.33; 95% CI: 1.31, 8.45; P = 0.011), but not OS ((HR = 2.78; 95% CI: 0.58, 13.22, P = 0.20). Grade 3+ adverse events occurred in 25%, 42%, and 33% of patients (arms A, B, and C). There were no differences between arms in neurocognitive decline comparing baseline to 3 months.

CONCLUSIONS

TMZ-alone patients experienced significantly shorter PFS than patients treated on the RT arms. The ongoing CODEL trial has been redesigned to compare RT + PCV versus RT + TMZ.

Extensive brainstem infiltration, not mass effect, is a common feature of end-stage cerebral glioblastomas

BACKGROUND

Progress in extending the survival of glioblastoma (GBM) patients has been slow. A better understanding of why patient survival remains poor is critical to developing new strategies. Postmortem studies on GBM can shed light on why patients are dying.

METHODS

The brains of 33 GBM patients were autopsied and examined for gross and microscopic abnormalities. Clinical-pathologic correlations were accomplished through detailed chart reviews. Data were compared with older published autopsy GBM studies that predated newer treatment strategies, such as more extensive surgical resection and adjuvant temozolomide.

RESULTS

In older GBM autopsy series, mass effect was observed in 72% of brains, with herniation in 50% of all cases. Infiltration of tumor into the brainstem was noted in only 21% of those older cases. In the current series, only 10 of 33 (30%) GBMs showed mass effect (P = 0.0003), and only 1 (3%) showed herniation (P < 0.0001). However, extensive GBM infiltration of the brainstem was present in 22 cases (67%, P < 0.0001), with accompanying destruction of the pons and white matter tracts. There was a direct correlation between longer median patient survival and the presence of brainstem infiltration (16.1 mo in brainstem-invaded cases vs 9.0 mo in cases lacking extensive brainstem involvement; P = 0.0003).

CONCLUSIONS

With improving care, severe mass effect appears to be less common in GBM patients today, whereas dissemination, including life-threatening brainstem invasion, is now more pronounced. This has major implications regarding preclinical GBM models, as well as the design of clinical trials aimed at further improving patient survival.

Phase II study of zolbetuximab plus pembrolizumab in claudin 18.2: Positive locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma (G/GEJ)—ILUSTRO Cohort 3

TPS260

Background: Five-year survival with advanced G/GEJ is poor, and limited biomarkers exist to inform optimal treatment selection. Pembrolizumab, an anti–programmed death-1 receptor (PD-1) antibody, is approved for advanced/metastatic PD-ligand 1–positive (PD-L1+) G/GEJ that progressed after ≥2 lines of therapy. The transmembrane tight junction protein claudin 18.2 (CLDN18.2) is normally confined to gastric mucosa but is often overexpressed in G/GEJ with roughly one-third of patients (pts) having high expression (≥75%). Zolbetuximab, a chimeric IgG1 monoclonal antibody, binds to CLDN18.2 and mediates cancer cell death through antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity. Phase 2 (NCT01630083) results showed prolonged survival with zolbetuximab + epirubicin, oxaliplatin, and capecitabine (EOX) vs EOX alone in G/GEJ. Results of nonclinical studies showed enhanced antitumor activity with zolbetuximab + anti-murine PD-1 antibody, and it was hypothesized that a combination with pembrolizumab (new Cohort 3) might augment ADCC and antitumor immune response in CLDN18.2 overexpressing G/GEJ. Methods: This phase 2 open-label study (NCT03505320) will enroll ~112 adult pts from 22 sites in 5 countries into 3 cohorts; this abstract describes Cohort 3 (~62 pts). Key eligibility criteria are advanced/metastatic G/GEJ, measurable disease (RECIST v1.1), adequate organ function and performance status, and high/intermediate (Cohort 3A) or high (Cohort 3B) expression of CLDN18.2. Central testing of tumor tissue will determine CLDN18.2 expression; pts are considered CLDN18.2 positive (CLDN18.2+) if ≥75% (high) or ≥50% to < 75% (intermediate) of tumor cells demonstrate moderate-to-strong membranous IHC staining. Patients in Cohort 3B are required to be PD-L1+, defined as a combined positive score ≥1 (IHC staining per the Dako 22C3 PD-L1 assay). Patients will receive zolbetuximab + pembrolizumab in the third/later line in Cohort 3A and third line in Cohort 3B. In Cohort 3A (safety cohort), zolbetuximab will be administered at a loading dose of 800 mg/m2 IV on Day 1 Cycle 1 followed by 600 mg/m2 IV every 3 weeks; a reduction from 600 mg/m2 every 3 weeks is permitted. Pembrolizumab 200 mg IV will be administered on Day 1 of each 21-day cycle. Cohort 3B (expansion cohort) zolbetuximab dose is determined from results of Cohort 3A. Imaging will occur every 6 weeks for 24 weeks and every 12 weeks thereafter. The primary endpoint is objective response rate; additional endpoints include duration of response, disease control rate, and progression-free survival by independent review committee and investigator assessment. Pharmacokinetics, safety/tolerability, quality of life, and immunogenicity will be assessed. The study is currently recruiting pts. Clinical trial information: NCT03505320.

Advanced Age Increases Immunosuppression in the Brain and Decreases Immunotherapeutic Efficacy in Subjects with Glioblastoma

PURPOSE

Wild-type isocitrate dehydrogenase-expressing glioblastoma (GBM) is the most common and aggressive primary brain tumor with a median age at diagnosis of ≥65 years. It accounts for approximately 90% of all GBMs and has a median overall survival (OS) of <15 months. Although immune checkpoint blockade (ICB) therapy has achieved remarkable survival benefits in a variety of aggressive malignancies, similar success has yet to be achieved for GBM among phase III clinical trials to date. Our study aimed to understand the relationship between subject age and immunotherapeutic efficacy as it relates to survival from glioma.

EXPERIMENTAL DESIGN

(i) Clinical data: GBM patient datasets from The Cancer Genome Atlas, Northwestern Medicine Enterprise Data Warehouse, and clinical studies evaluating ICB were stratified by age and compared for OS. (ii) Animal models: young, middle-aged, and older adult wild-type and indoleamine 2,3 dioxygenase (IDO)-knockout syngeneic mice were intracranially engrafted with CT-2A or GL261 glioma cell lines and treated with or without CTLA-4/PD-L1 mAbs, or radiation, anti-PD-1 mAb, and/or a pharmacologic IDO enzyme inhibitor.

RESULTS

Advanced age was associated with decreased GBM patient survival regardless of treatment with ICB. The advanced age-associated increase of brain IDO expression was linked to the suppression of immunotherapeutic efficacy and was not reversed by IDO enzyme inhibitor treatment.

CONCLUSIONS

Immunosuppression increases in the brain during advanced age and inhibits antiglioma immunity in older adults. Going forward, it will be important to fully understand the factors and mechanisms in the elderly brain that contribute to the decreased survival of older patients with GBM during treatment with ICB.

The Impact of Perioperative Arterial Infarct on Recurrence, Functional Outcomes, and Survival in Glioblastoma Patients

Background: Perioperative infarcts are a known complication that can occur during the resection of glioblastoma (GBM). Recent studies suggest that gross total and even "supra-total" resections may be associated with an increased survival but the rate of complications, including perioperative ischemia, may increase with these more aggressive resection strategies. However, little is known about the impact that perioperative infarcts have on survival, functional outcomes, and tumor recurrence patterns. Our study attempted to quantify and characterize the functional consequences of a perioperative infarct, as well as risk factors associated with occurrence. Methods: Seventy-three patients with a diagnosis of GBM and perioperative ischemia by MRI were identified from the electronic medical record system. We obtained demographic, prognostic, and stroke risk factor data. Infarct volumes were calculated from diffusion-weighted MRI scans, and subjects were segregated into an infarct cohort or a control cohort based on whether the identified lesion appeared to be an infarct in an arterial distribution or instead appeared to be expected postoperative changes. A multivariate statistical analysis was performed on the dataset. Results: Median age was 58.6 years, median post-op KPS (Karnofsky Performance Status) was 90, and median extent of resection (based on MRI) was 97.8%. Overall, perioperative arterial infarcts were uncommon (2.0%), did not have a statistically significant impact on survival (17.9 vs. 18.9 months), did not worsen neurologic function, and did not alter the pattern of recurrence. Conclusion: Perioperative arterial infarcts were uncommon in our patients despite aggressive resection and when present had no impact on survival or neurologic function. Given the clear benefit of maximal tumor resection, the risk of perioperative infarct should not deter maximal safe resection.

Response assessment of meningioma: 1D, 2D, and volumetric criteria for treatment response and tumor progression

BACKGROUND

Meningiomas are the most common primary brain tumors in adults. Due to their variable growth rates and irregular tumor shapes, response assessment in clinical trials remains challenging and no standard criteria have been defined. We evaluated 1D, 2D, and volume imaging criteria to assess whether a volumetric approach might be a superior surrogate for overall survival (OS).

METHODS

In this retrospective multicenter study, we evaluated the clinical and imaging data of 93 patients with recurrent meningiomas treated with pharmacotherapy. One-dimensional (1D), 2D, and volumetric measurements of enhancing tumor on pre- and post-treatment MRI were compared at 6 and 12 months after treatment initiation. Cox proportional hazards models were used to examine the relationship between each imaging criterion and OS.

RESULTS

The median age of the patient cohort is 51 years (range 12-88), with 14 World Health Organization (WHO) grade I, 53 WHO grade II, and 26 WHO grade III meningiomas. Volumetric increase of 40% and unidimensional increase by 10 mm at 6 months and 12 months provided the strongest association with overall survival (HR = 2.58 and 3.24 respectively, p<0.01). Setting a volume change threshold above 40% did not correlate with survival. The interobserver agreement of 1D, 2D, and volume criteria is only moderate (kappa = 0.49, 0.46, 0.52, respectively). None of the criteria based on tumor size reduction were associated with OS (P > 0.09).

CONCLUSION

Compared with 1D (Response Evaluation Criteria In Solid Tumors 1.1) and 2D (Response Assessment in Neuro-Oncology) approaches, volumetric criteria for tumor progression has a stronger association with OS, although the differences were only modest. The interobserver variability is moderate for all 3 methods. Further validation of these findings in an independent patient cohort is needed.

NRG/RTOG 1122: A phase 2, double-blinded, placebo-controlled study of bevacizumab with and without trebananib in patients with recurrent glioblastoma or gliosarcoma

BACKGROUND

Targeting vascular endothelial growth factor (VEGF) alone does not improve overall survival (OS) in recurrent glioblastoma (rGBM). The angiopoiein (Ang)-TIE2 system may play a role in tumor survival under VEGF inhibition. We conducted a phase 2, double-blinded, placebo-controlled trial of bevacizumab plus trebananib (a novel Fc fusion protein that sequesters Ang1/Ang2) over bevacizumab alone in rGBM.

METHODS

Patients ≥18 years of age with a Karnofsky performance status ≥70 and GBM or variants in first or second relapse were randomized to bevacizumab 10 mg/kg every 2 weeks plus trebananib 15 mg/kg every week or bevacizumab plus placebo. The primary endpoint was 6-month progression-free survival (PFS).

RESULTS

After an initial 6-patient lead-in cohort confirmed the safety of combining bevacizumab and trebananib, 115 eligible patients were randomized to the control (n = 58) or experimental treatment (n = 57). In the control arm, 6-month PFS was 41.1%, median survival time was 11.5 months (95% CI, 8.4-14.2 months), median PFS was 4.8 months (95% CI, 3.8-7.1 months), and radiographic response (RR) was 5.9%. In the experimental arm, 6-month PFS was 22.6%, median survival time was 7.5 months (95% CI, 6.8-10.1 months), median PFS was 4.2 months (95% CI, 3.7-5.6 months), and RR was 4.2%. The rate of severe toxicities was not significantly different between arms.

CONCLUSION

The combination of bevacizumab and trebananib was well tolerated but did not significantly improve 6-month PFS rate, PFS, or OS for patients with rGBM over bevacizumab alone. The shorter PFS in the experimental arm with a hazard ratio of 1.51 (P = .04) suggests that the addition of trebananib to bevacizumab is detrimental.

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.

Primary Central Nervous System Lymphoma-PART 2: Modern Therapeutic Management and Future Directions

Primary central nervous system (CNS) lymphoma, a rare CNS neoplasm associated with high mortality, is responsive to therapeutic interventions. In Part 1 of our two-part coverage of this entity, we provided an overview of the epidemiology of primary CNS lymphoma, followed by a discussion of the diagnostic and staging evaluation, and a review of current prognostication systems. In Part 2, we discuss the management of primary CNS lymphoma, focusing in particular on systemic therapies and radiation. With respect to systemic therapies, we provide details of a variety of regimens built around a backbone of high-dose methotrexate. Future directions for the treatment of primary CNS lymphoma are reviewed as well. These include optimization of consolidation regimens and the pursuit of novel agents.

Primary Central Nervous System Lymphoma-PART 1: Epidemiology, Diagnosis, Staging, and Prognosis

Primary central nervous system (CNS) lymphoma is a rare CNS neoplasm. Its highest incidence is in the elderly and the immunocompromised. The initial steps in establishing a diagnosis involve CNS imaging. Familiarity with the clinical presentation is important in order to limit the risk of a nondiagnostic biopsy. In addition to confirming the diagnosis, it is wise to evaluate for extra-CNS disease. There are important differences in the presentation and evaluation of immunocompetent patients and those of immunocompromised patients; we will delineate these in this review. Appropriate initial clinical evaluations facilitate optimal therapeutic management for patients with primary CNS lymphoma. This is of particular importance because primary CNS lymphoma is a potentially curable disease, despite the high likelihood of recurrence.

Cerebrospinal fluid circulating tumor cells (CSF CTC) for real-time patient monitoring and response to treatment

11549

Background: The validated CellSearch system (Janssen Diagnostics, LLC), utilizing an immunomagnetic CTC selection method based on EPCAM antibody conjugated ferroparticles, is an FDA-approved methodology for enumerating CTC from blood in pts with breast, prostate and colon cancers. The CellSearch system has been used to evaluate CSF CTC of pts with leptomeningeal metastasis (LM) and has demonstrated potential as a diagnostic marker and response to cancer treatment. We explored the use of CSF CTC enumeration in the follow-up of pts with LM from HER2+ cancers receiving intrathecal (IT) therapy, aimed at characterizing changes over time as a potential biomarker of treatment response. Methods: CSF from pts participating in an IRB-approved phase I/II dose escalation trial of IT trastuzumab for LM in HER2+ cancer (NCT01325207) was evaluated by CellSearch system. 3 ml CSF from a ventricular reservoir was collected for CSF CTC enumeration at pre-treatment Day 1 of each cycle and correlated with CSF cytology from the same sample, and with clinical and radiographic response. LM progression was defined as clinical, CSF cytologic or radiographic worsening. Results: 15 pts with HER2+ LM (14 breast, 1 colon) were enrolled; 13 were women. At baseline 7 pts had positive CSF cytology, the other patients had a diagnosis by MRI. Of the 15 pts, 10 had greater than 1 cycle of treatment to be evaluable; 5 pts progressed during cycle 1 (Table). Mean CSF CTC at baseline was 82 per 3ml (range 0-200); 2 pts had no detectable CSF CTCs. A numerical decrease in CSF CTC was observed in 5 pts after cycle 1 and remained low (mean =9.5, range 0-92) while disease was stable. 3 pts (pts.3, 4 and 7) demonstrated a rise in CSF CTCs roughly 1 month prior to disease progression. Conclusions: Changes in CSF CTCs enumeration in response to treatment may allow quantitative surveillance of treatment response. CSF CTCs may serve as a platform to assess treatment response or as an early biomarker of LM progression and should be further investigated. Clinical trial information: NCT01325207. [Table: see text]

Phase 1 open-label, multiple ascending dose trial of AGEN1884, an anti-CTLA-4 monoclonal antibody, in advanced solid malignancies

3075

Background: AGEN1884 is a fully human IgG1 monoclonal antibody targeting the co-inhibitory protein cytotoxic T lymphocyte-associated protein 4 (CTLA-4). CTLA-4 blockade has been shown to augment T cell activation and proliferation, resulting in immune infiltration of the tumor and subsequent regression. Objectives: Assess the safety, maximum tolerated dose (MTD), and pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of AGEN1884 in patients (pts) with advanced and refractory malignancies using a “3+3” trial design. Methods: Eleven pts have been enrolled and treated to date. AGEN1884 was administered intravenously q3w for 4 doses and then q12w. Three (0.1, 0.3 and 1 mg/kg) of six (3, 6 and 10 mg/kg) planned dose levels have been completed. Results: Five pts were accrued at 0.1 mg/kg dose level (2 were not DLT evaluable) and three pts each at doses of 0.3 mg/kg and 1 mg/kg. Median age was 56 years (range 26–70), ECOG 0–2, with a median of 4 (range 1–8) prior therapies. No DLT events have been observed thus far. Data from 5 pts were available for PK evaluation. Half-life of AGEN1884 post first dose was 8.8 and 9.6 days for 0.3 mg/kg and 0.1 mg/kg dose levels, respectively, as measured by ELISA. As of Jan 31, 2017, pts across cohorts were followed for a median of 6 weeks (range 0-28). Six pts (54.5%) have come off study due to disease progression, while 5 (45.5 %) remain on study. One confirmed partial response (80% reduction) by RECIST criteria was seen at 0.1 mg/kg in a patient with angiosarcoma. Conclusions: AGEN1884 is safe at 0.1 and 0.3 mg/kg dose levels. Dose escalation is ongoing and updated safety and PK data will be presented. Clinical trial information: NCT02694822.

A phase II study of bevacizumab and erlotinib after radiation and temozolomide in MGMT unmethylated GBM patients

Survival for glioblastoma (GBM) patients with an unmethyated MGMT promoter in their tumor is generally worse than methylated MGMT tumors, as temozolomide (TMZ) response is limited. How to better treat patients with unmethylated MGMT is unknown. We performed a trial combining erlotinib and bevacizumab in unmethylated GBM patients after completion of radiation (RT) and TMZ. GBM patients with an unmethylated MGMT promoter were trial eligible. Patient received standard RT (60 Gy) and TMZ (75 mg/m2 × 6 weeks) after surgical resection of their tumor. After completion of RT they started erlotinib 150 mg daily and bevacizumab 10 mg/kg every 2 weeks until progression. Imaging evaluations occurred every 8 weeks. The primary endpoint was overall survival. Of the 48 unmethylated patients enrolled, 46 were evaluable (29 men and 17 women); median age was 55.5 years (29-75) and median KPS was 90 (70-100). All patients completed RT with TMZ. The median number of cycles (1 cycle was 4 weeks) was 8 (2-47). Forty-one patients either progressed or died with a median progression free survival of 9.2 months. At a follow up of 33 months the median overall survival was 13.2 months. There were no unexpected toxicities and most observed toxicities were categorized as CTC grade 1 or 2. The combination of erlotinib and bevacizumab is tolerable but did not meet our primary endpoint of increasing survival. Importantly, more trials are needed to find better therapies for GBM patients with an unmethylated MGMT promoter.

Central Nervous System Cancers, Version 1.2015

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Central Nervous System (CNS) Cancers provide interdisciplinary recommendations for managing adult CNS cancers. Primary and metastatic brain tumors are a heterogeneous group of neoplasms with varied outcomes and management strategies. These NCCN Guidelines Insights summarize the NCCN CNS Cancers Panel's discussion and highlight notable changes in the 2015 update. This article outlines the data and provides insight into panel decisions regarding adjuvant radiation and chemotherapy treatment options for high-risk newly diagnosed low-grade gliomas and glioblastomas. Additionally, it describes the panel's assessment of new data and the ongoing debate regarding the use of alternating electric field therapy for high-grade gliomas.

Convection-Enhanced and Local Delivery of Targeted Cytotoxins in the Treatment of Malignant Gliomas

Despite advances in our knowledge about the genesis, molecular biology, and natural history of malignant gliomas and the use of a multi-disciplinary approach to their treatment, patients harboring this diagnosis continue to face a grim prognosis. At the time of diagnosis, patients typically undergo surgery for the establishment of a histologic diagnosis, the reduction of tumor burden, and the relief of mass effect, with the maintenance of the patient's neurological function in mind. This is followed by the administration of adjuvant therapeutics, including radiation therapy and chemotherapy.

Many investigational agents with laboratory evidence of efficacy against malignant gliomas have not met their promise in the clinical setting, largely due to the barriers that they must overcome to reach the tumor at a therapeutically meaningful concentration for a durable period of time. The relevant aspects of the blood-brain barrier, blood-tumor barrier, and blood-cerebrospinal fluid barrier, as they pertain to the delivery of agents to the tumor, will be discussed along with the strategies devised to circumvent them. This discussion will be followed by a description of agents currently in preclinical and clinical development, many of which are the result of intense ongoing research into the molecular biology of gliomas.

A phase II trial evaluating the effects and intra-tumoral penetration of bortezomib in patients with recurrent malignant gliomas

One resistance mechanism in malignant gliomas (MG) involves nuclear factor-κB (NF-κB) activation. Bortezomib prevents proteasomal degradation of NF-κB inhibitor α (NFKBIA), an endogenous regulator of NF-κB signaling, thereby limiting the effects of NF-κB on tumor survival and resistance. A presurgical phase II trial of bortezomib in recurrent MG was performed to determine drug concentration in tumor tissue and effects on NFKBIA. Patients were enrolled after signing an IRB approved informed consent. Treatment was bortezomib 1.7 mg/m(2) IV on days 1, 4 and 8 and then surgery on day 8 or 9. Post-operatively, treatment was Temozolomide (TMZ) 75 mg/m(2) PO on days 1-7 and 14-21 and bortezomib 1.7 mg/m(2) on days 7 and 21 [1 cycle was (1) month]. Ten patients were enrolled (8 M and 2 F) with 9 having surgery. Median age and KPS were 50 (42-64) and 90 % (70-100). The median cycles post-operatively was 2 (0-4). The trial was stopped as no patient had a PFS-6. All patients are deceased. Paired plasma and tumor bortezomib concentration measurements revealed higher drug concentrations in tumor than in plasma; NFKBIA protein levels were similar in drug-treated vs. drug-naïve tumor specimens. Nuclear 20S proteasome was less in postoperative samples. Postoperative treatment with TMZ and bortezomib did not show clinical activity. Bortezomib appears to sequester in tumor but pharmacological effects on NFKBIA were not seen, possibly obscured due to downregulation of NFKBIA during tumor progression. Changes in nuclear 20S could be marker of bortezomib effect on tumor.

Improving vaccine efficacy against malignant glioma

The effective treatment of adult and pediatric malignant glioma is a significant clinical challenge. In adults, glioblastoma (GBM) accounts for the majority of malignant glioma diagnoses with a median survival of 14.6 mo. In children, malignant glioma accounts for 20% of primary CNS tumors with a median survival of less than 1 y. Here, we discuss vaccine treatment for children diagnosed with malignant glioma, through targeting EphA2, IL-13Rα2 and/or histone H3 K27M, while in adults, treatments with RINTEGA, Prophage Series G-100 and dendritic cells are explored. We conclude by proposing new strategies that are built on current vaccine technologies and improved upon with novel combinatorial approaches.

The kynurenine to tryptophan ratio as a prognostic tool for glioblastoma patients enrolling in immunotherapy

We hypothesized that peripheral tryptophan (Trp) and/or kynurenine (Kyn) levels would provide prognostic value for physicians planning to enroll glioblastoma multiforme (GBM) patients in immunotherapy. GBM is the most common form of malignant glioma in adults. Despite aggressive surgical resection, irradiation and chemotherapy, patients with GBM have a median survival of only 14.6 months after diagnosis. This poor outcome has led to the search for more effective treatments, including immunotherapy. However, the identification of parameters that proactively stratify GBM patients who have the potential for therapeutic benefit has been challenging. Given recent observations demonstrating high indoleamine 2,3 dioxygenase 1 (IDO1) expression in GBM, the immunosuppressive impact of IDO1-mediated Trp catabolism, as well as active transport of Trp and the IDO1-downstream Trp catabolite, Kyn, across the blood brain barrier, we hypothesized that peripheral blood analysis of this pathway would provide diagnostic utility. When comparing individuals without tumors to GBM patients prior to surgical resection, or at the 48 hour (48 h) and ⩾10 week (10 w+) postoperative time points, Trp levels were significantly decreased (p<0.0002). Similarly, Kyn levels were decreased in the pre- and 48 h postoperative GBM patients (p<0.0001), while there was no difference between individuals without tumors and 10 w+ GBM patients. Interestingly, those 10 w+ patients with a high Kyn/Trp ratio (⩾9.5) had a mean overall survival (OS) of 23.6 ± a standard error of 6.8 months, compared to an OS of 38.7 ± 4.9 months for patients with lower Kyn/Trp values. Since the 10 w+ blood draw and analyses occurred prior to patient enrollment in the heat shock protein peptide complex-96 clinical trial, these novel data suggest that the late Kyn/Trp index may be a relevant clinical benchmark, providing prognostic value for GBM patients who are enrolled in immunotherapeutic regimens.

Abstract 4389: Liposomes containing piperazine compounds inhibit tumor growth in a patient-derived xenograft model of glioblastoma multiforme

Glioblastoma multiforme (GBM) is fatal in nearly all instances, and responds poorly to current standards of care. GBMs exhibit resistance to chemotherapy which leads to tumor recurrence following initial surgical debulking. We have recently developed an 80 nm liposome containing a novel hydrophobic microtubule disrupting piperazine. This novel nanostructure, called IM-1 nanobin, contains 500-1000 piperazine drug molecules encapsulated in the hydrophobic inner leaflet of the lipid bilayer in each liposome. This nanoparticle inhibited the proliferation of GBM cells in vitro, although its cytotoxicity was reduced (3-5 fold) compared to free drug dissolved in DMSO. Results from FACS analysis showed that sub-micromolar concentrations of IM-1 caused G2/M phase cell cycle arrest and apoptosis of U87 GBM cells, as well as early passage GBM cells derived from a patient-derived xenograft (PDX). In collaboration with the Northwestern Brain Tumor Institute, we have established a panel of PDX. Since these tumors are not propagated in culture, they preserve the mixture of tumor cells and stroma critical for conducting meaningful therapy response experiments. IM-1 was evaluated in GBM PDX propagated in subcutaneous and intracranial compartments. In mice bearing subcutaneous PDX tumors, IM-1 treatment delayed the growth of the tumors compared to free drug alone; orthotopic GBM PDX studies are ongoing. Our results show that a novel liposome encapsulated piperazine, IM-1, is a promising new nanostructure for development as a therapeutic for treating patients with GBM.

Citation Format: Elden P. Swindell, Andrey Ugolkov, Christian Freguia, Oleksii Dubrovskyi, Patrick L. Hankins, Jeong Yang, Jeffrey J. Raizer, James P. Chandler, Charles David James, Andrew P. Mazar, Thomas V. O'Halloran. Liposomes containing piperazine compounds inhibit tumor growth in a patient-derived xenograft model of glioblastoma multiforme. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4389. doi:10.1158/1538-7445.AM2015-4389

Central nervous system cancers, version 2.2014. Featured updates to the NCCN Guidelines

The NCCN Guidelines for Central Nervous System Cancers provide multidisciplinary recommendations for the clinical management of patients with cancers of the central nervous system. These NCCN Guidelines Insights highlight recent updates regarding the management of metastatic brain tumors using radiation therapy. Use of stereotactic radiosurgery (SRS) is no longer limited to patients with 3 or fewer lesions, because data suggest that total disease burden, rather than number of lesions, is predictive of survival benefits associated with the technique. SRS is increasingly becoming an integral part of management of patients with controlled, low-volume brain metastases.

Phase II study of panobinostat in combination with bevacizumab for recurrent glioblastoma and anaplastic glioma

BACKGROUND

Panobinostat is a histone deacetylase inhibitor with antineoplastic and antiangiogenic effects in glioma that may work synergistically with bevacizumab. We conducted a multicenter phase II trial of panobinostat combined with bevacizumab in patients with recurrent high-grade glioma (HGG).

METHODS

Patients with recurrent HGG were treated with oral panobinostat 30 mg 3 times per week, every other week, in combination with bevacizumab 10 mg/kg every other week. The primary endpoint was a 6-month progression-fee survival (PFS6) rate for participants with recurrent glioblastoma (GBM). Patients with recurrent anaplastic glioma (AG) were evaluated as an exploratory arm of the study.

RESULTS

At interim analysis, the GBM arm did not meet criteria for continued accrual, and the GBM arm was closed. A total of 24 patients with GBM were accrued prior to closure. The PFS6 rate was 30.4% (95%, CI 12.4%-50.7%), median PFS was 5 months (range, 3-9 months), and median overall survival (OS) was 9 months (range, 6-19 months). Accrual in the AG arm continued to completion, and a total of 15 patients were enrolled. The PFS6 rate was 46.7% (range, 21%-73%), median PFS was 7 months (range, 2-10 months), and median OS was 17 months (range, 5 months-27 months).

CONCLUSIONS

This phase II study of panobinostat and bevacizumab in participants with recurrent GBM did not meet criteria for continued accrual, and the GBM cohort of the study was closed. Although it was reasonably well tolerated, the addition of panobinostat to bevacizumab did not significantly improve PFS6 compared with historical controls of bevacizumab monotherapy in either cohort.

Phase II study of monthly pasireotide LAR (SOM230C) for recurrent or progressive meningioma

OBJECTIVE

A subset of meningiomas recur after surgery and radiation therapy, but no medical therapy for recurrent meningioma has proven effective.

METHODS

Pasireotide LAR is a long-acting somatostatin analog that may inhibit meningioma growth. This was a phase II trial in patients with histologically confirmed recurrent or progressive meningioma designed to evaluate whether pasireotide LAR prolongs progression-free survival at 6 months (PFS6). Patients were stratified by histology (atypical [World Health Organization grade 2] and malignant [grade 3] meningiomas in cohort A and benign [grade 3] in cohort B).

RESULTS

Eighteen patients were accrued in cohort A and 16 in cohort B. Cohort A had median age 59 years, median Karnofsky performance status 80, 17 (94%) had previous radiation therapy, and 11 (61%) showed high octreotide uptake. Cohort B had median age 52 years, median Karnofsky performance status 90, 11 (69%) had previous radiation therapy, and 12 (75%) showed high octreotide uptake. There were no radiographic responses to pasireotide LAR therapy in either cohort. Twelve patients (67%) in cohort A and 13 (81%) in cohort B achieved stable disease. In cohort A, PFS6 was 17% and median PFS 15 weeks (95% confidence interval: 8-20). In cohort B, PFS6 was 50% and median PFS 26 weeks (12-43). Treatment was well tolerated. Octreotide uptake and insulin-like growth factor-1 levels did not predict outcome. Expression of somatostatin receptor 3 predicted favorable PFS and overall survival.

CONCLUSIONS

Pasireotide LAR has limited activity in recurrent meningiomas. The finding that somatostatin receptor 3 is associated with favorable outcomes warrants further investigation.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that in patients with recurrent or progressive meningioma, pasireotide LAR does not significantly increase the proportion of patients with PFS at 6 months.

Economics of Malignant Gliomas: A Critical Review

PURPOSE

Approximately 18,500 persons are diagnosed with malignant glioma in the United States annually. Few studies have investigated the comprehensive economic costs. We reviewed the literature to examine costs to patients with malignant glioma and their families, payers, and society.

METHODS

A total of 18 fully extracted studies were included. Data were collected on direct and indirect costs, and cost estimates were converted to US dollars using the conversion rate calculated from the study's publication date, and updated to 2011 values after adjustment for inflation. A standardized data abstraction form was used. Data were extracted by one reviewer and checked by another.

RESULTS

Before approval of effective chemotherapeutic agents for malignant gliomas, estimated total direct medical costs in the United States for surgery and radiation therapy per patient ranged from $50,600 to $92,700. The addition of temozolomide (TMZ) and bevacizumab to glioblastoma treatment regimens has resulted in increased overall costs for glioma care. Although health care costs are now less front-loaded, they have increased over the course of illness. Analysis using a willingness-to-pay threshold of $50,000 per quality-adjusted life-year suggests that the benefits of TMZ fall on the edge of acceptable therapies. Furthermore, indirect medical costs, such as productivity losses, are not trivial.

CONCLUSION

With increased chemotherapy use for malignant glioma, the paradigm for treatment and associated out-of-pocket and total medical costs continue to evolve. Larger out-of-pocket costs may influence the choice of chemotherapeutic agents, the economic implications of which should be evaluated prospectively.

NT113, a pan-ERBB inhibitor with high brain penetrance, inhibits the growth of glioblastoma xenografts with EGFR amplification

This report describes results from our analysis of the activity and biodistribution of a novel pan-ERBB inhibitor, NT113, when used in treating mice with intracranial glioblastoma (GBM) xenografts. Approaches used in this investigation include: bioluminescence imaging (BLI) for monitoring intracranial tumor growth and response to therapy; determination of survival benefit from treatment; analysis of tumor IHC reactivity for indication of treatment effect on proliferation and apoptotic response; Western blot analysis for determination of effects of treatment on ERBB and ERBB signaling mediator activation; and high-performance liquid chromatography for determination of NT113 concentration in tissue extracts from animals receiving oral administration of inhibitor. Our results show that NT113 is active against GBM xenografts in which wild-type EGFR or EGFRvIII is highly expressed. In experiments including lapatinib and/or erlotinib, NT113 treatment was associated with the most substantial improvement in survival, as well as the most substantial tumor growth inhibition, as indicated by BLI and IHC results. Western blot analysis results indicated that NT113 has inhibitory activity, both in vivo and in vitro, on ERBB family member phosphorylation, as well as on the phosphorylation of downstream signaling mediator Akt. Results from the analysis of animal tissues revealed significantly higher NT113 normal brain-to-plasma and intracranial tumor-to-plasma ratios for NT113, relative to erlotinib, indicating superior NT113 partitioning to intracranial tissue compartments. These data provide a strong rationale for the clinical investigation of NT113, a novel ERBB inhibitor, in treating patients with GBM.

Abstract 1941: GSK3 signaling is critical to glioma stem cell growth and survival

GSK3 is an attractive therapeutic target in cancer, known for its role in regulating proliferation, differentiation, metabolism, and apoptosis. Previous studies demonstrate the effectiveness of GSK3 inhibition on established glioma cell lines and patient-derived glioma stem cell lines in vitro and in vivo. In glioma cell lines, GSK3 inhibition induces apoptosis through c-MYC activation, mitochondrial destabilization, and reduction of NF-κB activity. We have characterized a novel set of GSK3 inhibitors for their ability to inhibit glycogen synthase phosphorylation, reduce levels of XIAP, and induce cell death in cancer cells. However, it is uncertain if this mechanism is functional with respect to cancer stem cells and glioma tumor subtype. The need to investigate the mechanistic effects of GSK3 in cancer stem cells is important given their malignancy, innate resistance to therapy, and tumorigenicity. Moreover, the intracellular signaling and transcription networks may differ in glioma stem cells, particularly among cells with different subtypes. We have recently demonstrated that cancer stem cells isolated from glioma patients can be segregated into either a proneural or mesenchymal subtype based on their gene expression pattern. The oncogenic activity of genes like c-MYC in glioma stem cells and differences between glioma stem cell subtypes, such as NF-κB activation, raises questions as to whether GSK3 inhibition will be effective against both subtypes and if their effects utilize distinct mechanisms of inhibition. In this study, we examine the effects of two established and two novel GSK3 inhibitors on glioma stem cells with respect to tumor subtype and investigate their mechanisms of action. Our in vitro data shows that GSK3 inhibition significantly reduces growth and causes cell death in both proneural and mesenchymal glioma stem cells. Using a glioma stem cell xenograft model, we test the effectiveness of GSK3 inhibition as a single agent and in conjunction with clinically-approved chemotherapeutic agents. The characterization of cancer stem cell inhibitors and their effectiveness in different tumor subtypes has significant clinical implications. Our work supports the therapeutic potential of novel GSK3 inhibitors for the treatment of malignant gliomas.

Note: This abstract was not presented at the meeting.

Citation Format: Angel Alvarez, Andrey Ugolkov, Irina Gaisina, Alan P. Kozikowski, Kaushal Joshi, Sunghak Kim, Ichiro Nakano, Jeffrey J. Raizer, Andrew P. Mazar, Bo Hu, Shi-Yuan Cheng. GSK3 signaling is critical to glioma stem cell growth and survival. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1941. doi:10.1158/1538-7445.AM2014-1941

Financial burden experienced by patients undergoing treatment for malignant gliomas

BACKGROUND

Patients undergoing treatment for malignant gliomas (MGs) can encounter medical costs beyond what their insurance covers. The magnitude and type of costs experienced by patients are unknown. The purpose of this study was to have patients or their families report on the medical costs incurred during the patients MG treatment.

METHODS

Patients with MG were eligible if they were within 6 months of diagnosis or tumor recurrence. Patients had to be ≥18 years of age, fluent in English, and not aphasic. Weekly logbooks were issued to patients for recording associated costs for ∼6 months or until tumor progression. "Out-of-pocket" (OOP) costs included medical and nonmedical expenses that were not reimbursed by insurance. Direct medical costs included hospital and physician bills. Direct nonmedical costs included transportation, parking, and other related items. Indirect medical costs included lost wages. Costs were analyzed to provide mean and medians with range of expenses.

RESULTS

Forty-three patients provided cost data for a median of 12 weeks. There were 25 men and 18 women with a median age of 57 years (range, 24y-73y); 79% were married, and 49% reported annual income >$75 000. Health insurance coverage was preferred provider organizations for 58% of patients, and median deductible was $1 500. Median monthly OOP cost was $1 342 (mean, $2 451; range, $333.41-$17 267.16). The highest OOP median costs were medication copayments ($710; range, $0-13 611.20), transportation ($327; range, $0-$1 927), and hospital bill copayments ($403; range, $0-$4 000). Median lost wages were $7 500, and median lost days of work were 12.8.

CONCLUSIONS

OOP costs for MG patients can be significant and comprise direct and indirect costs across several areas. Informing patients about expected costs could limit additional duress and allow financial support systems to be implemented.

Concordance of patient and caregiver reports in evaluating quality of life in patients with malignant gliomas and an assessment of caregiver burden

BACKGROUND

Given the neurocognitive impairment experienced by many patients with malignant gliomas, caregiver reports can be critical in assessing the quality of life (QOL) of these patients. In this study, we explored whether assessment of patient QOL by the primary caregiver shows concordance with the patient's self-reported QOL, and we quantified the burden faced by caregivers.

METHODS

QOL of 45 patients was evaluated by both the patient and primary caregiver on 3 or more separate occasions using the Functional Assessment of Cancer Therapy-Brain (FACT-Br) instrument, and concordance between the 2 reports was evaluated. Caregiver burden was measured using the Caregiver Quality of Life Index-Cancer (CQOL-C) instrument.

RESULTS

Overall, good concordance was observed between the patient and caregiver FACT-Br reports (intraclass correlation coefficient = 0.74). Patient-reported FACT-Br scores were 4.75 (95% CI, 1.44-8.05) points higher than paired caregiver reports on the 200-point scale (P = .008); however, this difference did not achieve clinical significance. Caregiver burden, as measured by the CQOL-C, was significantly greater among caregivers in this study than those previously reported for caregivers of patients with lung, breast, or prostate cancer (P < .001).

CONCLUSIONS

Despite minor discrepancies in caregiver assessments of patient QOL relative to patient self-reports, our results suggest that the caregiver assessments can serve as adequate proxies for patient reports. Our results also illustrate the particularly heavy burden faced by caregivers of patients with malignant glioma. Further research into both of these areas is warranted.

Central nervous system cancers

Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at NCCN. org, contains recommendations on additional subtypes.

Diffusion abnormalities of the corpus callosum in patients receiving bevacizumab for malignant brain tumors: suspected treatment toxicity

Bevacizumab has been reported to cause diffusion restriction in the tumor bed of patients with malignant gliomas. This study evaluated prolonged diffusion restriction, in the corpus callosum (CC), of patients with malignant brain tumors treated with bevacizumab. We retrospectively reviewed our database of patients treated with bevacizumab for malignant brain tumors looking for those with restricted diffusion in the CC. CC ADC ratio measurements were obtained prior to and following treatment. Correlation was made with biopsy (n = 3) and MR perfusion (n = 7) and PET (n = 4). The temporal evolution of these changes relative to therapy was examined with mixed effects regression analysis. Nine patients (eight malignant gliomas, one malignant meningioma) out of 146 patients were found to have developed areas of diffusion restriction in the CC. These areas tended to enlarge and coalesce over serial MRIs and persisted for up to 22 months. Hypoperfusion was demonstrated in MR perfusion in 7/7. PET was hypometabolic in all 4. Biopsy of the CC showed no tumor in 3/3. ADC ratio measurements indicated a significant overall effect of time (F(16,60) = 11.2; p < 0.0001), consistent with persistent diffusion restriction over the measured time periods. Bevacizumab causes prolonged diffusion restriction in the CC. The negative MR perfusion, FDG PET and histopathology suggest this is a toxicity of bevacizumab and not active tumor. Awareness of these changes can assist in patient care.