Oncolytic DNX-2401 virotherapy plus pembrolizumab in recurrent glioblastoma: a phase 1/2 trial

Immune-mediated anti-tumoral responses, elicited by oncolytic viruses and augmented with checkpoint inhibition, may be an effective treatment approach for glioblastoma. Here in this multicenter phase 1/2 study we evaluated the combination of intratumoral delivery of oncolytic virus DNX-2401 followed by intravenous anti-PD-1 antibody pembrolizumab in recurrent glioblastoma, first in a dose-escalation and then in a dose-expansion phase, in 49 patients. The primary endpoints were overall safety and objective response rate. The primary safety endpoint was met, whereas the primary efficacy endpoint was not met. There were no dose-limiting toxicities, and full dose combined treatment was well tolerated. The objective response rate was 10.4% (90% confidence interval (CI) 4.2-20.7%), which was not statistically greater than the prespecified control rate of 5%. The secondary endpoint of overall survival at 12 months was 52.7% (95% CI 40.1-69.2%), which was statistically greater than the prespecified control rate of 20%. Median overall survival was 12.5 months (10.7-13.5 months). Objective responses led to longer survival (hazard ratio 0.20, 95% CI 0.05-0.87). A total of 56.2% (95% CI 41.1-70.5%) of patients had a clinical benefit defined as stable disease or better. Three patients completed treatment with durable responses and remain alive at 45, 48 and 60 months. Exploratory mutational, gene-expression and immunophenotypic analyses revealed that the balance between immune cell infiltration and expression of checkpoint inhibitors may potentially inform on response to treatment and mechanisms of resistance. Overall, the combination of intratumoral DNX-2401 followed by pembrolizumab was safe with notable survival benefit in select patients (ClinicalTrials.gov registration: NCT02798406).

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.

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.

A Bayesian adaptive randomized phase II multicenter trial of bevacizumab with or without vorinostat in adults with recurrent glioblastoma

BACKGROUND

Bevacizumab has promising activity against recurrent glioblastoma (GBM). However, acquired resistance to this agent results in tumor recurrence. We hypothesized that vorinostat, a histone deacetylase (HDAC) inhibitor with anti-angiogenic effects, would prevent acquired resistance to bevacizumab.

METHODS

This multicenter phase II trial used a Bayesian adaptive design to randomize patients with recurrent GBM to bevacizumab alone or bevacizumab plus vorinostat with the primary endpoint of progression-free survival (PFS) and secondary endpoints of overall survival (OS) and clinical outcomes assessment (MD Anderson Symptom Inventory Brain Tumor module [MDASI-BT]). Eligible patients were adults (≥18 y) with histologically confirmed GBM recurrent after prior radiation therapy, with adequate organ function, KPS ≥60, and no prior bevacizumab or HDAC inhibitors.

RESULTS

Ninety patients (bevacizumab + vorinostat: 49, bevacizumab: 41) were enrolled, of whom 74 were evaluable for PFS (bevacizumab + vorinostat: 44, bevacizumab: 30). Median PFS (3.7 vs 3.9 mo, P = 0.94, hazard ratio [HR] 0.63 [95% CI: 0.38, 1.06, P = 0.08]), median OS (7.8 vs 9.3 mo, P = 0.64, HR 0.93 [95% CI: 0.5, 1.6, P = 0.79]) and clinical benefit were similar between the 2 arms. Toxicity (grade ≥3) in 85 evaluable patients included hypertension (n = 37), neurological changes (n = 2), anorexia (n = 2), infections (n = 9), wound dehiscence (n = 2), deep vein thrombosis/pulmonary embolism (n = 2), and colonic perforation (n = 1).

CONCLUSIONS

Bevacizumab combined with vorinostat did not yield improvement in PFS or OS or clinical benefit compared with bevacizumab alone or a clinical benefit in adults with recurrent GBM. This trial is the first to test a Bayesian adaptive design with adaptive randomization and Bayesian continuous monitoring in patients with primary brain tumor and demonstrates the feasibility of using complex Bayesian adaptive design in a multicenter setting.

Differentiation of 2-hydroxyglutarate enantiomers and its lactones by gas chromatography/electron ionization tandem mass spectrometry

RATIONALE

2-Hydroxyglutarate (2-hg) exists as enantiomers and can readily undergo cyclization to its lactone. Gas chromatography/electron ionization mass spectrometry (GC/EI-MS) has been used to separate 2-hg enantiomers in bodily fluids but the assay cannot simultaneously measure cyclic and acylic 2-hg enantiomers. Furthermore, the assignment of ion structures was not verified by complementary MS data.

METHODS

GC/EI-MS and product ion analysis were used to obtain MS and MS/MS spectra of 2-hg, deuterated and ¹³ C-labeled 2-hg, and 2-hg lactone. Ion structures and EI fragmentation mechanisms were determined by fragmentation pattern and isotopologue comparisons. Using the EI data, a GC/MS/MS assay was developed to separate and detect 2-hg enantiomers and 2-hg lactone enantiomers in blood and urine using a cyclodextrin capillary column.

RESULTS

A new ion structure was predicted for the 85 m/z fragment than what was previously hypothesized, and the 117 m/z ion was the only fragment unique to the linear 2-hg compound. MS/MS data suggested that the majority of the fragments were the result of secondary fragmentation. Finally, separation of serum and urine 2-hg and 2-hg lactone enantiomers was achieved, and the acyclic 2-hg compound was found to be the major compound detected, though the amount of lactone detected was considerable in a number of samples.

CONCLUSIONS

Unique EI fragmentation pathways for both 2-hg and the 2-hg lactone have been described. Subsequently, the GC/MS/MS assay presented herein has significant potential as a novel clinical assay as it separates and detects both 2-hg enantiomers and the 2-hg lactone enantiomers, a capability which has not been previously demonstrated by any other assay to date.

OS10.6 Infigratinib (BGJ398) in patients with recurrent gliomas with fibroblast growth factor receptor (FGFR) alterations: a multicenter phase II study

BACKGROUND

FGFR mutations and translocations occur in approximately 10% of glioblastomas (GBMs). FGFR3-TACC3 fusion has been reported as predictive of response to FGFR tyrosine kinase inhibitor therapy both pre-clinically and clinically. Infigratinib (BGJ398) is a selective small-molecule pan-FGFR kinase inhibitor that has demonstrated anti-tumor activity in several solid tumors with FGFR genetic alterations. Therefore, we conducted a phase II trial to test the efficacy of infigratinib in FGFR-altered recurrent GBM (NCT01975701).

METHODS

This open-label trial accrued adults with recurrent high-grade gliomas following failure of initial therapy that harbored FGFR1-TACC1 or FGFR3-TACC3 fusions; activating mutations in FGFR1, 2 or 3; or FGFR1, 2, 3, or 4 amplification. Oral infigratinib was administered 125 mg on days 1–21 every 28 days. Prophylaxis for hyperphosphatemia, a common toxicity, was recommended. The primary endpoint was the 6-month progression-free survival (6mPFS) rate by RANO (locally assessed, estimated by K-M method), with a goal of >40%.

RESULTS

As of the Sep 2017 data cut-off, 26 patients (16 men, 10 women; median age 55 years, range 20–76 years; 50% with ≥2 prior regimens) were treated, and 24 (92.3%) discontinued for disease progression (n=21) or other reasons (n=3). All patients had FGFR1 or FGFR3 gene alterations, and 4 had >1 gene alteration. The estimated 6mPFS rate was 16% (95% CI 5.0–32.5%); median PFS was 1.7 months (95% CI 1.1–2.8 months); median OS was 6.7 months (95% CI 4.2–11.7 months); ORR was 7.7% (95% CI 1.0–25.1%). The best overall response was: partial response 7.7% (FGFR1 mutation n=1; FGFR3 amplification n=1); stable disease 26.9%; progressive disease 50.0%; missing/unknown 15.3%. The most common (>15%) all-grade treatment-related adverse events (AEs) were hyperphosphatemia, fatigue, diarrhea, hyperlipasemia, and stomatitis. There were no grade 4 treatment-related AEs. Eleven patients (42.3%) had treatment-related AEs requiring dose interruptions or reductions (most commonly hyperphosphatemia).

CONCLUSIONS

Infigratinib induced partial response or stable disease in approximately one-third of patients with recurrent GBM and/or other glioma subtypes harboring FGFR alterations. Most AEs were reversible and manageable. Further potential combinations are being explored in patients with proven FGFR-TACC fusion genes and analysis of biomarker data is ongoing.

Liquid biopsy in central nervous system metastases: a RANO review and proposals for clinical applications

Liquid biopsies collect and analyze tumor components in body fluids, and there is an increasing interest in the investigation of liquid biopsies as a surrogate for tumor tissue in the management of both primary and secondary brain tumors. Herein we critically review available literature on spinal fluid and plasma circulating tumor cells (CTCs) and cell-free tumor (ctDNA) for diagnosis and monitoring of leptomeningeal and parenchymal brain metastases. We discuss technical issues and propose several potential applications of liquid biopsies in different clinical settings (ie, for initial diagnosis, for assessment during treatment, and for guidance of treatment decisions). Last, ongoing clinical studies on CNS metastases that include liquid biopsies are summarized, and recommendations for future clinical studies are provided.

Phase 1 lead-in to a phase 2 factorial study of temozolomide plus memantine, mefloquine, and metformin as postradiation adjuvant therapy for newly diagnosed glioblastoma

BACKGROUND

Repurposed memantine, mefloquine, and metformin have putative anticancer activity. The objective of this phase 1 study was to determine the maximum tolerated doses (MTDs) of combinations of these agents with temozolomide (TMZ).

METHODS

Adults with newly diagnosed glioblastoma who completed chemoradiation were eligible. The patients were assigned to receive doublet, triplet, or quadruplet therapy with TMZ combined with mefloquine, memantine, and/or metformin. Dose-limiting toxicities (DLTs) were determined, using a 3 + 3 study design.

RESULTS

Of 85 enrolled patients, 4 did not complete cycle 1 (the DLT observation period) for nontoxicity reasons, and 81 were evaluable for DLT. The MTDs for doublet therapy were memantine 20 mg twice daily, mefloquine 250 mg 3 times weekly, and metformin 850 mg twice daily. For triplet therapy, the MTDs were memantine 10 mg twice daily, mefloquine 250 mg 3 times weekly, and metformin 850 mg twice daily. For quadruplet therapy, the MTDs were memantine 10 mg twice daily, mefloquine 250 mg 3 times weekly, and metformin 500 mg twice daily. DLTs included dizziness (memantine) and gastrointestinal effects (metformin). Lymphopenia was the most common adverse event (66%). From study entry, the median survival was 21 months, and the 2-year survival rate was 43%.

CONCLUSIONS

Memantine, mefloquine, and metformin can be combined safely with TMZ in patients with newly diagnosed glioblastoma.

Most common sites on MRI of intracranial neoplastic leptomeningeal disease

Neoplastic leptomeningeal disease (LMD) represents infiltration of the leptomeninges by tumor cells. Knowledge of the frequencies of locations of LMD on MRI may assist in early detection, help elucidate the process of leptomeningeal spread of cancer and understand how LMD affects the central nervous system. Our goal was to identify intracranial sites of neoplastic LMD predilection on MRI in patients with cytologically-proven LMD. The presence of FLAIR signal hyperintensity and T1-weighted post-contrast enhancement in the sulci of the supratentorial compartment and cerebellum and enhancement of the cranial nerves (CNs), basal cisterns, pituitary stalk, and ependymal surface of the lateral ventricles, as well as the presence of parenchymal metastasis were recorded. Within each imaging sequence, sites were ordered by prevalence and compared using McNemar's test. The study included 270 patients. Positive MRI findings were present in 185/270 (68.5%) patients. FLAIR signal hyperintensity was significantly more common (p≤0.003) in the cerebellum (n=96) and occipital lobe (n=92) relative to the other lobes. Leptomeningeal enhancement was also significantly more common (p≤0.009) in the cerebellum (n=82) and occipital lobe (n=67) relative to the other lobes. Enhancement was most commonly found involving CN VII/VIII and the ependymal surface of the lateral ventricles compared to other sites. Parenchymal metastases were present in 110 (40.1%) of the patients. In conclusion, neoplastic LMD predominantly involves the cerebellum and occipital lobes, CN VII/VIII, and the ependymal lining of the lateral ventricles. Parenchymal metastases are frequently present in patients with neoplastic LMD.

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]

Leptomeningeal metastases: a RANO proposal for response criteria

Leptomeningeal metastases (LM) currently lack standardization with respect to response assessment. A Response Assessment in Neuro-Oncology (RANO) working group with expertise in LM developed a consensus proposal for evaluating patients treated for this disease. Three basic elements in assessing response in LM are proposed: a standardized neurological examination, cerebral spinal fluid (CSF) cytology or flow cytometry, and radiographic evaluation. The group recommends that all patients enrolling in clinical trials undergo CSF analysis (cytology in all cancers; flow cytometry in hematologic cancers), complete contrast-enhanced neuraxis MRI, and in instances of planned intra-CSF therapy, radioisotope CSF flow studies. In conjunction with the RANO Neurological Assessment working group, a standardized instrument was created for assessing the neurological exam in patients with LM. Considering that most lesions in LM are nonmeasurable and that assessment of neuroimaging in LM is subjective, neuroimaging is graded as stable, progressive, or improved using a novel radiological LM response scorecard. Radiographic disease progression in isolation (ie, negative CSF cytology/flow cytometry and stable neurological assessment) would be defined as LM disease progression. The RANO LM working group has proposed a method of response evaluation for patients with LM that will require further testing, validation, and likely refinement with use.

Leptomeningeal metastases presenting exclusively with ocular disturbance in 34 patients: A tertiary care cancer hospital experience

Leptomeningeal disease (LMD) represents disseminated intracranial metastatic disease that requires early detection and initiation of therapy. Patients with LMD typically present with a variety of neurologic problems, including ocular disturbances. However, little is reported on LMD presenting exclusively with ocular-related disturbances in the absence of any other central nervous system (CNS) dysfunction. Our goal was to describe the workup for ocular disturbances in the setting of known cancer diagnosis. Retrospective case study utilizing prospectively collected database at a tertiary cancer care center for all patients with diagnosis of LMD between 2001 and 2009. Main outcome was descriptive analysis of ocular findings by primary or admitting service with or without formal ophthalmology exam in workup for LMD. 34 patients demonstrated ocular disturbances without any other CNS manifestations. Our findings demonstrate that 71% of ocular disturbances were detected by the primary admitting services. Formal consultation with ophthalmology resulted in the detection of the remaining cases. The most common findings were cranial nerve deficits, papilledema, and optic disc or retinal infiltration by tumor. These findings supported a further work-up for CNS disease. Therefore, it is appropriate to refer cancer patients with visual complaints or findings on exam to ophthalmology to evaluate for evidence suggestive of LMD that may support a further work-up.

Association between 18F-FDG PET/CT and MRI appearance of spinal leptomeningeal disease before and after treatment at a tertiary referral center

OBJECTIVE

Leptomeningeal disease (LMD), the presence of metastasis in the subarachnoid space, has devastating implications if left untreated. The gold standard for LMD diagnosis is cytologic analysis of cerebrospinal fluid (CSF); MRI is also used to evaluate suspected LMD. The purpose of this study was to compare the appearance of LMD in the spinal canal on 18F-FDG PET/CT imaging with the appearance of LMD on MRI and with CSF cytology.

METHODS

In twenty-one patients with cytologically-proven spinal LMD, findings on 18F-FDG PET/CT, MRI, and CSF cytology at diagnosis of LMD and after the initiation of treatment for LMD were retrospectively reviewed.

RESULTS

At diagnosis of LMD, abnormal 18F-FDG avidity was demonstrated in the spinal canal in six patients, and the anatomic distribution of 18F-FDG activity corresponded to the sites of LMD on MRI. All six of these patients were then treated with intrathecal chemotherapy. Follow-up 18F-FDG PET/CT and MRI were obtained in four of the six cases. In all four cases, normalization of 18F-FDG activity in the spinal canal and reduction of enhancement on MRI corresponded to the cytologic response to treatment, as determined by CSF analysis.

CONCLUSION

18F-FDG avidity in the spinal canal greater than the normal contents of the canal can suggest spinal LMD. This abnormal avidity may be detected before the diagnosis of LMD has been established with MRI or CSF cytology. The spinal canal should be routinely evaluated on 18F-FDG PET/CT in patients with suspected LMD so that appropriate treatment is initiated.

A phase II, multicenter trial of rindopepimut (CDX-110) in newly diagnosed glioblastoma: the ACT III study

BACKGROUND

The epidermal growth factor receptor variant III deletion mutation, EGFRvIII, is expressed in ∼30% of primary glioblastoma and linked to poor long-term survival. Rindopepimut consists of the unique EGFRvIII peptide sequence conjugated to keyhole limpet hemocyanin. In previous phase II trials (ACTIVATE/ACT II), rindopepimut was well tolerated with robust EGFRvIII-specific immune responses and promising progression-free and overall survival. This multicenter, single-arm phase II clinical trial (ACT III) was performed to confirm these results.

METHODS

Rindopepimut and standard adjuvant temozolomide chemotherapy were administered to 65 patients with newly diagnosed EGFRvIII-expressing (EGFRvIII+) glioblastoma after gross total resection and chemoradiation.

RESULTS

Progression-free survival at 5.5 months (∼8.5 mo from diagnosis) was 66%. Relative to study entry, median overall survival was 21.8 months, and 36-month overall survival was 26%. Extended rindopepimut vaccination (up to 3.5+ years) was well tolerated. Grades 1-2 injection site reactions were frequent. Anti-EGFRvIII antibody titers increased ≥4-fold in 85% of patients, and increased with duration of treatment. EGFRvIII was eliminated in 4/6 (67%) tumor samples obtained after >3 months of therapy.

CONCLUSIONS

This study confirms, in a multicenter setting, the preliminary results seen in previous phase II trials of rindopepimut. A pivotal, double-blind, randomized, phase III trial ("ACT IV") is under way.

Randomized phase II adjuvant factorial study of dose-dense temozolomide alone and in combination with isotretinoin, celecoxib, and/or thalidomide for glioblastoma

BACKGROUND

Chemoradiation, followed by adjuvant temozolomide, is the standard treatment for newly diagnosed glioblastoma. Adding other active agents may enhance treatment efficacy.

METHODS

The primary objective of this factorial phase II study was to determine if one of 3 potential chemotherapy agents added to dose-dense temozolomide (ddTMZ) improves progression-free survival (PFS) for patients with newly diagnosed glioblastoma. A prior phase I trial established the safety of combining ddTMZ with isotretinoin, celecoxib, and/or thalidomide. Adults with good performance status and no evidence of progression post chemoradiation were randomized into 8 arms: ddTMZ alone (7 days on/7 days off) or doublet, triplet, and quadruplet combinations with isotretinoin, celecoxib, and thalidomide.

RESULTS

The study enrolled 155 participants with a median age of 53 years (range, 18-84 y). None of the agents demonstrated improved PFS when compared with arms not containing that specific agent. There was no difference in PFS for triplet compared with doublet regimens, although a trend for improved overall survival (OS) was seen (20.1 vs 17.0 months, P = .15). Compared with ddTMZ, the ddTMZ + isotretinoin doublet had worse PFS (10.5 vs 6.5 months, P = .043) and OS (21.2 vs 11.7 months, P = .037). Trends were also seen for worse outcomes with isotretinoin-containing regimens, but there was no impact with celecoxib or thalidomide combinations. Treatment was well tolerated with expected high rates of lymphopenia.

CONCLUSIONS

The results do not establish a benefit for these combinations but indicate that adding isotretinoin to ddTMZ may be detrimental. This study demonstrated the feasibility and utility of the factorial design in efficiently testing drug combinations in newly diagnosed glioblastoma.

CLINICALTRIALSGOV IDENTIFIER

NCT00112502.

Leptomeningeal metastasis: a Response Assessment in Neuro-Oncology critical review of endpoints and response criteria of published randomized clinical trials

PURPOSE

To date, response criteria and optimal methods for assessment of outcome have not been standardized in patients with leptomeningeal metastasis (LM).

METHODS

A Response Assessment in Neuro-Oncology working group of experts in LM critically reviewed published literature regarding randomized clinical trials (RCTs) and trial design in patients with LM.

RESULTS

A literature review determined that 6 RCTs regarding the treatment of LM have been published, all of which assessed the response to intra-CSF based chemotherapy. Amongst these RCTs, only a single trial attempted to determine whether intra-CSF chemotherapy was of benefit compared with systemic therapy. Otherwise, this pragmatic question has not been formally addressed in patients with solid cancers and LM. The methodology of the 6 RCTs varied widely with respect to pretreatment evaluation, type of treatment, and response to treatment. Additionally there was little uniformity in reporting of treatment-related toxicity. One RCT suggests no advantage of combined versus single-agent intra-CSF chemotherapy in patients with LM. No specific intra-CSF regimen has shown superior efficacy in the treatment of LM, with the exception of liposomal cytarabine in patients with lymphomatous meningitis. Problematic with all RCTs is the lack of standardization with respect to response criteria. There was considerable variation in definitions of response by clinical examination, neuroimaging, and CSF analysis.

CONCLUSION

Based upon a review of published RCTs in LM, there exists a significant unmet need for guidelines for evaluating patients with LM in clinical practice as well as for response assessment in clinical trials.

Phase I/II study of erlotinib and temsirolimus for patients with recurrent malignant gliomas: North American Brain Tumor Consortium trial 04-02

BACKGROUND

Inhibition of epidermal growth factor receptor (EGFR) and the mechanistic target of rapamycin (mTOR) may have synergistic antitumor effects in high-grade glioma patients.

METHODS

We conducted a phase I/II study of the EGFR inhibitor erlotinib (150 mg/day) and the mTOR inhibitor temsirolimus. Patients initially received temsirolimus 50 mg weekly, and the dose adjusted based on toxicities. In the phase II component, the primary endpoint was 6-month progression-free survival (PFS6) among glioblastoma patients.

RESULTS

Twenty-two patients enrolled in phase I, 47 in phase II. Twelve phase I patients treated at the maximum tolerated dosage were included in the phase II cohort for analysis. The maximum tolerated dosage was 15 mg temsirolimus weekly with erlotinib 150 mg daily. Dose-limiting toxicities were rash and mucositis. Among 42 evaluable glioblastoma patients, 12 (29%) achieved stable disease, but there were no responses, and PFS6 was 13%. Among 16 anaplastic glioma patients, 1 (6%) achieved complete response, 1 (6%) partial response, and 2 (12.5%) stable disease, with PFS6 of 8%. Tumor levels of both drugs were low, and posttreatment tissue in 3 patients showed no reduction in the mTOR target phosphorylated (phospho-)S6(S235/236) but possible compensatory increase in phospho-Akt(S473). Presence of EGFR variant III, phospho-EGFR, and EGFR amplification did not correlate with survival, but patients with elevated phospho-extracellular signal-regulated kinase or reduced phosphatase and tensin homolog protein expression had decreased progression-free survival at 4 months.

CONCLUSION

Because of increased toxicity, the maximum tolerated dosage of temsirolimus in combination with erlotinib proved lower than expected. Insufficient tumor drug levels and redundant signaling pathways may partly explain the minimal antitumor activity noted.

The identification and characterization of breast cancer CTCs competent for brain metastasis

Brain metastatic breast cancer (BMBC) is uniformly fatal and increasing in frequency. Despite its devastating outcome, mechanisms causing BMBC remain largely unknown. The mechanisms that implicate circulating tumor cells (CTCs) in metastatic disease, notably in BMBC, remain elusive. We characterize CTCs isolated from peripheral blood mononuclear cells of patients with breast cancer and also develop CTC lines from three of these patients. In epithelial cell adhesion molecule (EpCAM)-negative CTCs, we identified a potential signature of brain metastasis comprising "brain metastasis selected markers (BMSMs)" HER2+ / EGFR+ / HPSE+ / Notch1+. These CTCs, which are not captured by the CellSearch platform because of their EpCAM negativity, were analyzed for cell invasiveness and metastatic competency in vivo. CTC lines expressing the BMSM signature were highly invasive and capable of generating brain and lung metastases when xenografted in nude mice. Notably, increased brain metastatic capabilities, frequency, and quantitation were detected in EpCAM- CTCs overexpressing the BMSM signature. The presence of proteins of the BMSM CTC signature was also detected in the metastatic lesions of animals. Collectively, we provide evidence of isolation, characterization, and long-term culture of human breast cancer CTCs, leading to the description of a BMSM protein signature that is suggestive of CTC metastatic competency to the brain.

Breast cancer and leptomeningeal disease (LMD): hormone receptor status influences time to development of LMD and survival from LMD diagnosis

Leptomeningeal disease (LMD) occurs in 5 % of breast cancer patients. The aim of this study was to identify risk factors related to survival and time to development of LMD in breast cancer patients. A retrospective analysis of breast cancer patients with LMD, evaluated in MDACC between 1995 and 2011. 103 patients with diagnosis of breast cancer and LMD were identified (one male). The median age at LMD diagnosis was 49.2 years. 78.2 % had invasive ductal carcinoma. Hormone receptors (HRs) were positive in 55.3 % of patients, 47.4 % were human epidermal growth factor receptor 2-positive and 22.8 % were triple negative. 52 % of the patients were treated with WBRT, 19 % with spinal radiation, 36 % with systemic chemotherapy and 55 % with intrathecal chemotherapy. Estimated median overall survival from time of breast cancer diagnosis was 3.66 years. Median survival from time of LMD diagnosis was 4.2 months. Time from breast cancer diagnosis to LMD was 2.48 years. In multivariate analysis, HR status and stage at diagnosis were significantly associated with time to LMD diagnosis (p < 0.05). In triple negative patients, time to LMD was shorter. In patients who were HR positive, time to LMD was longer. Survival from LMD diagnosis was significantly associated with both treatment, as well as positive HR status (multivariate analysis p < 0.05). In conclusion LMD has dismal prognosis in breast cancer patients. HR status contributes to time to LMD diagnosis and survival from LMD diagnosis. The impact of treatment aimed at LMD cannot be ascertained in our retrospective study due to the inherent bias associated with the decision to treat.

Phase I lead-in to a 2x2x2 factorial trial of dose-dense temozolomide, memantine, mefloquine, and metformin as postradiation adjuvant therapy of glioblastoma (GBM)

TPS2106

Background: Treatment for GBM is an area of unmet need. Despite optimal therapy, survival is poor and 2nd line therapies are scarce. There is an urgent need to find better treatments for recurrence, but also more effective 1st line therapies. Dose-dense temozolomide (ddTMZ) using the 7/14-day regimen has shown promising preliminary results in combination with cytostatic agents. Memantine (MEM) is a glutamate receptor (NMDA) blocker with antiproliferation properties and possibly neuroprotective effect. Mefloquine (MFQ) induces autophagy and apoptosis. Metformin (MFM) has mTOR inhibitor properties. Methods: Trial Design: Phase I/II trial to evaluate adjuvant ddTMZ with MEM MFQ and MFM. Primary objective Phase I: MTDs of ddTMZ with MEM/MFQ/MFM, 3+3 design. MTDs will be the recommended Phase II doses for a subsequent randomized factorial Phase II trial (ddTMZ alone and single, double and triple combinations). Accrual of about 55 eligible patients was calculated for Phase I (48-144). Clinical trial registry number is NCT01430351. Treatment planned: Patients accrued sequentially to ddTMZ with 1, 2, or 3 drugs. Arm 1 (ddTMZ alone) will be enrolled in Phase II only. Patients were first accrued to 1-drug Arms 2-4. Once MTDs were determined, accrual started to 2-drug Arms 5-7. Once completed, accrual to Arm 8 will start. Arms 2-4 were started at a predetermined target dose, and deescalated if excessive toxicity. Treatment in Arms 5-8 will be escalated for each drug to reach MTDs of Arms 2-4. Major eligibility criteria: Adults (≥ 18) with supratentorial GBM, KPS ≥60, adequate bone marrow and organ function. Post chemoradiation MRI ≤14 days before enrollment on stable/decreasing steroids and no progression; registration ≤5 weeks of chemoradiation. Patients on MFQ: no EIAED, EKG without prolonged QTc or arrhythmia. Pregnancy not allowed; adequate contraception required. Informed consent in keeping with IRB policies. Current enrollment: To date, 49 patients started treatment and 18 are still active. Enrollment to Arms 2-4 and 6 is completed and MTDs determined. Accrual is ongoing in Arms 5 and 7, and pending in Arm 8. Clinical trial information: NCT01430351.

Bevacizumab (BEV) use in disseminated choroid plexus papilloma (DCCP)

e13039

Background: Choroid plexus papilloma (CCP) is a rare primary neuro-ectodermal tumor of the choroid plexus, representing less than 1% of intracranial tumors in adults. The most common location in adults is the 4th ventricle and treatment is gross total resection (GTR). Leptomeningeal disease (LMD) can rarely occur, even when the tumor retains benign histology. Because of the rarity of DCCP, there is no standard treatment, with less than 20 published cases. There have no previous descriptions of the use of BEV therapy in DCCP. Methods: We present 2 patients (pts) with DCCP, who received gross total resection, radiation and chemotherapy with continued progression, who received treatment with BEV therapy. Results: Pt 1 presented with a 4th ventricular mass and evidence of LMD. GTR of the posterior fossa lesion revealed an atypical CCP. The pt received craniospinal radiation with concurrent temozolomide (TMZ) therapy. After 4 years, there was leptomeningeal disease progression and the pt developed progressive radicular pain and weakness, unresponsive to typical treatments. He was initiated on TMZ and BEV therapy, but the TMZ was discontinued due to thrombocytopenia and the pt was continued on BEV alone. While the MRI showed stable disease at, the pt had complete remission of pain and some improvement of ataxia. When BEV was held due to toxicity, the pain returned until BEV was restarted. Carboplatin was added to BEV with progression of LMD at 21 months. Pt 2 is a 58-year-old man who present with a 4th ventricular mass, shown to be CCP after gross total resection. The pt received radiotherapy for diffuse sacral recurrence. After three years of surveillance, the pt received lomustine and 6-thioguanine for disease progression, limited to 5 cycles by thrombocytopenia. After 5 years, the pt noted continued progressive radicular pain in his lower extremities. The pt completed a planned course of 10 doses of bevacizumab and had improvement in pain control and stable imaging at 11 months. Conclusions: While bevacizumab resulted in stable imaging when used in DCCP, there was significant improvement in debilitating radicular symptoms. The complications of BEV therapy must be considered with the potential benefit of symptomatic relief. Prospective studies are needed.

BTTC08-01: A phase II study of bevacizumab and erlotinib after radiation therapy and temozolomide in patients with newly diagnosed glioblastoma (GBM) without MGMT promoter methylation

2019^

Background: Patients (pts) with GBM with unmethylated MGMT have a worse prognosis than those with methylated MGMT. Novel approaches for this poor risk group are warranted. The Brain Tumor Trials Collaborative (BTTC) performed a phase II trial evaluating standard chemoradiation followed by bevacizumab and erlotinib in patients with MGMT unmethylated GBM. EGFR and VEGFR are upregulated during radiation suggesting that this combination could be more effective than post-radiation adjuvant temozolomide (TMZ). Methods: After informed consent, adult patients with supratentorial GBM, KPS ≥ 70 and > 1 cm2 tumor block for MGMT promoter analysis were screened. Only tumors with confirmed unmethylated MGMT promoter were enrolled. All patients received RT + TMZ and then approximately 4 weeks after RT they received bevacizumab 10 mg/kg every 2 weeks and erlotinib 150 mg/day, continuously. One cycle was 4 weeks; evaluation by MRI was every 2 cycles. Treatment continued until disease progression or intolerable adverse events. Results: 115 patients were screened; 48 were enrolled (2 unevaluable: 1 for an infratentoral GBM and 1 withdrew after 7 days of treatment) with 29 men, 17 women. Median age was 56 yrs (29-75); median KPS was 90 (70-90). The median number of cycles was 8 (2-38) with 4 patients remaining on trial at the time of analysis. Objective responses: 4 CR, 12 PR and 30 SD. Median PFS is 7.3 months (95% CI (6.4, 11)) and median OS 14.2 months (95% CI (10.7, not reached)). There were no unexpected toxicities; grade 3/4 rate < 5%. Conclusions: Adjuvant bevacizumab and erlotinib in GBM with unmethylated MGMT is well tolerated. Preliminary efficacy data is comparable with outcomes in similar unmethylated MGMT patient populations from the EORTC/NCIC and RTOG 0525 studies. Tissue correlation is being performed. Clinical trial information: NCT00720356.

A phase I/II trial of pazopanib in combination with lapatinib in adult patients with relapsed malignant glioma

PURPOSE

Increased mitogenic signaling and angiogenesis, frequently facilitated by somatic activation of EGF receptor (EGFR; ErbB1) and/or loss of PTEN, and VEGF overexpression, respectively, drive malignant glioma growth. We hypothesized that patients with recurrent glioblastoma would exhibit differential antitumor benefit based on tumor PTEN/EGFRvIII status when treated with the antiangiogenic agent pazopanib and the ErbB inhibitor lapatinib.

EXPERIMENTAL DESIGN

A phase II study evaluated the antitumor activity of pazopanib 400 mg/d plus lapatinib 1,000 mg/d in patients with grade 4 malignant glioma and known PTEN/EGFRvIII status not receiving enzyme-inducing anticonvulsants (EIAC). The phase II study used a two-stage Green-Dahlberg design for futility. An independent, parallel phase I component determined the maximum-tolerated regimen (MTR) of pazopanib and lapatinib in patients with grade 3/4 glioma receiving EIACs.

RESULTS

The six-month progression-free survival (PFS) rates in phase II (n = 41) were 0% and 15% in the PTEN/EGFRvIII-positive and PTEN/EGFRvIII-negative cohorts, respectively, leading to early termination. Two patients (5%) had a partial response and 14 patients (34%) had stable disease lasting 8 or more weeks. In phase I (n = 34), the MTR was not reached. On the basis of pharmacokinetic and safety review, a regimen of pazopanib 600 mg plus lapatinib 1,000 mg, each twice daily, was considered safe. Concomitant EIACs reduced exposure to pazopanib and lapatinib.

CONCLUSIONS

The antitumor activity of this combination at the phase II dose tested was limited. Pharmacokinetic data indicated that exposure to lapatinib was subtherapeutic in the phase II evaluation. Evaluation of intratumoral drug delivery and activity may be essential for hypothesis-testing trials with targeted agents in malignant glioma.

Helping patients make the best decision regarding duration of temozolomide chemotherapy treatment

Outcomes for patients with glioblastoma have improved with the addition of temozolomide (TMZ) chemotherapy to radiation therapy followed by adjuvant TMZ for up to 1 year. Patients often wish to continue chemotherapy after the standard 1-year course. Whether to continue or to stop TMZ is a complex and stressful decision for the patient and family, and the decision should be based on a discussion of the known risks and benefits of each choice.

Randomized phase II 8-arm factorial study of adjuvant dose-dense (dd) temozolomide (TMZ) with permutations of thalidomide (Thal), isotretinoin (CRA), and/or celecoxib (Cel) for newly diagnosed glioblastoma (GBM)

2003

Background: Concurrent radiation and TMZ followed by 6-12 months of adjuvant TMZ (d 1-5 of a 28d cycle) is the current standard of care for patients with newly diagnosed GBM. The addition of cytostatic or signal transduction agents may enhance efficacy without a significant increase in toxicity. A phase I trial (Neuro-oncology 2009) established the safety of ddTMZ with 2 or 3 of the cytostatic agents. Methods: This randomized phase II study was conducted by the Brain Tumor Trials Collaborative (BTTC) and the MDACC CCOP. The primary objectives: determine if specific cytostatic agents added to ddTMZ alters outcomes (PFS, OS) and compare triplet with doublet therapy. Eligibility criteria: centrally confirmed newly diagnosed GBM, age ≥18, KPS≥60, stable or improved after chemoradiation (pseudoprogression allowed), adequate hematologic, renal and hepatic function. Pts were randomly assigned to 12 treatment cycles (28 d/cycle) in 8 arms: ddTMZ alone (150 mg/m2/day, 7-d on, 7-d off) or TMZ-containing doublet, triplet and quadruplet combinations with Thal, CRA, or Cel. Results: The study enrolled 155 eligible patients from 11/2005 to 9/2010 to the 8 arms of the factorial design. Median age was 53 (18-84) and median KPS, 90 (60-100). Compared with TMZ alone, the TMZ+CRA doublet had worse PFS (10.5, 6.5 mo; p=0.043) and OS (21.2, 11.7 mo; p=0.037). Trends were also seen for worse outcome (PFS, OS) for CRA-containing regimens, improved OS for Cel containing arms and no impact of Thal. A strong trend for OS improvement was seen for triplet compared with doublet regimens (20.1, 17.0 mo; p=0.15), but no difference for PFS. Treatment was well tolerated with expected high rates of grade 3/4 lymphopenia, and overall a modest toxicity rate. Conclusions: The results indicate that the addition of CRA to ddTMZ may be detrimental in patients with newly diagnosed GBM. This study demonstrated the utility of the factorial design in efficiently testing drug combinations, the impact of individual agents in these combinations as well as doublet vs. triplet regimens and supports its utility in testing combinations of targeted agents.

Impact of duration of bevacizumab (Bev) treatment in the prognosis of adults with recurrent malignant gliomas

2064

Background: Bev is the standard treatment for patients with recurrent glioblastoma (GB) but is also used in treating recurrent anaplastic gliomas (AG). Differences in outcome between these groups and optimal duration of treatment with Bev in pts with recurrent malignant gliomas are not well defined. We examined the relationship between the duration of Bev treatment and the outcome in pts with GB and AG. Methods: In this retrospective chart and data review derived from our longitudinal database, we identified pts with recurrent AG and GB who were treated with Bev alone or Bev-containing regimens between 2005 and 2009; the data was analyzed to determine the overall survival (OS) and the progression free survival (PFS). Results: A total of 261 patients with recurrent malignant gliomas (196 with GB and 65 with AG) were identified. There was no significant difference between the median length of treatment between AG and GB (5.81±0.66 months vs. 6.77±0.52 months, p=0.32). PFS6 was 34.2% (95% CI, 27.8-41.3) for patients with GB and 44.2% (95% CI, 32.5-56.7) for patients with AG. Patients with GB who were treated ≥6 months had a significantly higher OS (29.13 months vs. 20.16 months, p= 0.001) compared to those treated <6 months, and a significantly higher PFS compared to those treated <6months (11.33 months vs. 3.7 months, p=0.0001). For patients with AG, although treatment ≥6 months had a significantly higher PFS (13.93 months vs. 3.53 months, p<0.0001), OS was not significantly different (months 38.6 vs. 52.5 months, p=0.6) compared with those treated <6 months. Conclusions: Length of treatment ≥6 mo with Bev or Bev-containing regimen was associated with improved PFS in both AG and GB but only the GB subgroup showed improved OS. These results suggest equivocal survival benefit in patients with AG with longer duration of bevacizumab treatment, which requires further study in prospective trials.

Lenalidomide and irinotecan in adults with recurrent malignant gliomas: Phase I results of the phase I/II trial

2036

Background: Patients with recurrent malignant gliomas have limited treatment options. We previously reported promising results using 6 month progression free survival [PFS6] endpoint combining irinotecan and thalidomide compared to historical controls. In this study, we tested the tolerability and efficacy of Irinotecan combined with Lenalidomide, a more potent thalidomide analogue with unique antiangiogenic and immunomodulatory properties. Methods: This phase I portion of the phase I/II study aimed to determine the maximum tolerated doses (MTD) of irinotecan and lenalidomide. Eligible patients were adults (>=18 y) with recurrent WHO Grade 3 or 4 gliomas who were not on EIAED, had failed prior radiation therapy, had a KPS>=60, had adequate marrow, renal and hepatic organ function, no major medical illnesses and no other concurrent malignancies. Each cycle was designated as 4 weeks in duration. Results: Two of the 4 patients enrolled at the starting dose level of Lenalidomide 10 mg/day on days 1-21 and irinotecan 200 mg/m2 q2 weeks developed rash as dose limiting toxicity (DLT). The trial was restarted with no change in irinotecan dose but with a lowered Lenalidomide dose of 7.5 mg/day for cycle 1 with escalation to 10 mg/day for cycle 2 and beyond. Of 3 eligible patients enrolled, no DLTs were noted even after cycle 2. The dose was hence escalated to Lenalidomide 10 mg/day with unchanged irinotecan dose. Only 1/6 patients experienced a DLT (pulmonary embolism); however, it was noted that 4/6 patients required dose reduction of irinotecan to 150 mg/m2 after cycle 1. One patient died during cycle 2 of unknown causes (autopsy declined) without reports of preceding toxicities. Non DLT toxicities included neutropenia, leukopenia, hypokalemia, diarrhea, fatigue and nausea/vomiting. Lenalidomide pharmacokinetic data, obtained by serial blood draws initially after one dose of the drug on day 0 and subsequently after irinotecan and lenalidomide dose on day 1 to examine drug interactions, will be presented. Conclusions: Based on these results, the maximum tolerated dose was Lenalidomide 10 mg/day on days 1-21 and irinotecan 150 mg/m2 q 2 weeks every 28 days which will be used in the phase II study that will open shortly.

Bevacizumab versus bevacizumab plus vorinostat in adults with recurrent malignant glioma: Results of a phase I part of a phase I/II trial

2029^

Background: Antiangiogenic therapy using b evacizumab (Bev) has shown promising activity against recurrent glioblastoma (GBM). However, most patients have disease progression after striking but transient responses. Salvage therapies have been uniformly ineffective, suggesting development of resistance mechanisms including upregulation of other proangiogenic factors and increased activity of hypoxia inducible factors (HIF)-1a. Vorinostat, a histone deacetylase (HDAC) inhibitor has single agent activity against recurrent GBM and downregulates HIF-1a and other proangiogenic and invasive factors. We hypothesized that HDAC inhibition combined with Bev would result in improved clinical outcome. We report the results of the Phase I portion of the study preceding the initiation of the 2-arm adaptive randomized Phase II study. Methods: Adults with recurrent malignant glioma, KPS ≥ 60, normal hepatic, renal and marrow organ function and no prior exposure to Bev or Vorinostat were enrolled to the combination therapy after the confirmation of recurrent GBM. A conventional 3+3 Phase I design was used to determine the maximum tolerated dose (MTD) and the toxicity profile of the combination of Bev and Vorinostat. The starting dose was Bev at 10mg/kg administered on days 1 and 15 intravenously and Vorinostat 400 mg/day orally on days 1 to 7, and days 15 to 21 with each cycle being 28 days. Results: A total of 6 patients were enrolled and all 6 patients were evaluable. Three patients were enrolled in the first cohort at the starting dose of the combination and completed the first cycle. One patient experienced a grade 3 ALT elevation and grade 3 hyperglycemia, which were designated as possibly related to vorinostat and constituting a dose-limiting toxicity (DLT). No grade 4 toxicities were noted. The cohort was expanded by 3 more patients with none of these patients experienced a DLT in the first cycle. The starting dose level of Bev and v orinostat was declared the Phase II dose. Conclusions: Combination of Bev (10 mg/kg q 2 weeks) and of vorinostat (400 mg on days 1 to 7 and 15 to 21) has tolerable toxicity profile. This will be followed by a multicenter Bayesian adaptive randomized Phase II study.

Phase I pharmacologic and pharmacodynamic study of the gamma secretase (Notch) inhibitor MK-0752 in adult patients with advanced solid tumors

PURPOSE

Aberrant Notch signaling has been implicated in the pathogenesis of many human cancers. MK-0752 is a potent, oral inhibitor of γ-secretase, an enzyme required for Notch pathway activation. Safety, maximum-tolerated dose, pharmacokinetics (PKs), pharmacodynamics, and preliminary antitumor efficacy were assessed in a phase I study of MK-0752.

PATIENTS AND METHODS

MK-0752 was administered in three different schedules to patients with advanced solid tumors. Hair follicles were collected at higher dose levels to assess a gene signature of Notch inhibition.

RESULTS

Of 103 patients who received MK-0752, 21 patients received a continuous once-daily dosing at 450 and 600 mg; 17 were dosed on an intermittent schedule of 3 of 7 days at 450 and 600 mg; and 65 were dosed once per week at 600, 900, 1,200, 1,500, 1,800, 2,400, 3,200, and 4,200 mg. The most common drug-related toxicities were diarrhea, nausea, vomiting, and fatigue. PKs (area under the concentration-time curve and maximum measured plasma concentration) increased in a less than dose proportional manner, with a half-life of approximately 15 hours. Significant inhibition of Notch signaling was observed with the 1,800- to 4,200-mg weekly dose levels, confirming target engagement at those doses. One objective complete response and an additional 10 patients with stable disease longer than 4 months were observed among patients with high-grade gliomas.

CONCLUSION

MK-0752 toxicity was schedule dependent. Weekly dosing was generally well tolerated and resulted in strong modulation of a Notch gene signature. Clinical benefit was observed, and rational combination trials are currently ongoing to maximize clinical benefit with this novel agent.

P4-07-08: Subsets and Molecular Signatures of Circulating Tumor Cells in Breast Cancer Brain Metastasis

Background: Circulating tumor cells (CTCs) represent the “seeds” of intractable brain metastatic breast cancer (BMBC); however, properties of CTCs targeting the brain remain elusive. For example, the FDA-approved CTC platform (CellSearch™, Veridex, LLC) detects only CTCs positive for epithelial cell adhesion molecule (EpCAM) and cytokeratins (CKs), but is unable to capture any other CTC subtypes or analyze biomarkers of brain-homing CTCs. We hypothesized that profiling CTCs from BMBC patients might result in the identification of brain-colonizing CTC signatures. Materials and Methods: We employed CellSearch™ and a novel technology that uses analysis of specific antigenic markers by immunofluorescence, coupled with detecting gene amplification by fluorescence in situ hybridization on the same cells; and quantification of the signal via automated scanning (FICTION; BioView Duet-3™ system).

Results: We established that our approach was feasible by performing CTC analyses on peripheral blood mononuclear cells isolated from BMBC patients or patients not possessing overt metastatic disease. We detected a differential gene amplification for human epidermal growth factor receptor1 and 2 (EGFR and HER2, respectively). Second, the number of EpCAM-positive CTCs visualized by the BioView™ platform was at least three orders of magnitude higher than one obtained from CellSearch™ CTC analyses using the same specimen. Third, we identified the presence of CTCs positive for CKs but negative for EpCAM. Conversely, high levels of prometastatic heparanase, in conjunction with the expression of aldehyde dehydrogenase-1 (ALDH1), a known cancer stem-cell marker, were detected in CTCs from BMBC patients; with a correlation between heparanase, ALDH1, and high EGFR amplification. Finally, extensive flow cytometric/FACS analyses validated the presence of CTC subsets negative for EpCAM and CD45, a hematolymphoid marker, however enriched for heparanase/ALDH1 expression.

Discussion: These findings indicate that the BioView™ platform not only captures more EpCAM-positive CTCs than CellSearch™ but also allows the detection of novel CTC subtypes possessing varying EpCAM levels. Importantly, they suggest that profiling CTC subtypes in patients with BMBC can be relevant towards the discovery of BMBC founder CTCs. Work is ongoing to further characterize these CTC subtypes, and to assess their abilities to metastasize to brain in xenotransplantation studies using immunodeficient mice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-08.

Phase 2 trial of irinotecan and thalidomide in adults with recurrent anaplastic glioma

BACKGROUND

Therapeutic options for patients with anaplastic gliomas (AGs) are limited despite better insights into glioma biology. The authors previously reported improved outcome in patients with recurrent glioblastoma treated with thalidomide and irinotecan compared with historical controls. Here, results of the AG arm of the study are reported, using this drug combination.

METHODS

Adults with recurrent AG previously treated with radiation therapy, with Karnofsky performance score ≥70, adequate organ function and not on enzyme-inducing anticonvulsants were enrolled. Treatment was in 6-week cycles with irinotecan at 125 mg/m(2) weekly for 4 weeks followed by 2 weeks off, and thalidomide at 100 mg daily increased to 400 mg/day as tolerated. The primary endpoint was progression-free survival rate at 6 months (PFS-6), and the secondary endpoints were overall survival (OS) and response rate (RR).

RESULTS

In 39 eligible patients, PFS-6 for the intent-to-treat population was 36% (95% confidence interval [CI] = 21%, 53%), median PFS was 13 weeks (95% CI = 6%, 28%) and RR was 10%(95% CI = 3%, 24%). Radiological findings included 2 complete and 2 partial responses and 17 stable disease. Median OS from study registration was 62 weeks, (95% CI = 51, 144). Treatment-related toxicities (grade 3 or higher) included neutropenia, diarrhea, nausea, and fatigue; 6 patients experienced venous thromboembolism. Four deaths were attributable to treatment-related toxicities: 1 from pulmonary embolism, 2 from colitis, and 1 from urosepsis.

CONCLUSIONS

The combination of thalidomide and irinotecan did not achieve sufficient efficacy to warrant further investigation against AG, although a subset of patients experienced prolonged PFS/OS. A trial of the more potent thalidomide analogue, lenalidomide, in combination with irinotecan against AG is currently ongoing.

Leptomeningeal disease

Leptomeningeal metastasis (LMD) is a lethal complication caused by a variety of cancers, typically developing late in the disease course. It is associated with major neurologic disabilities and short survival. The incidence of LMD may increase because of longer survival of patients who have cancer, and because of the use of newer large-molecule therapies with poor central nervous system penetration. To achieve improved outcomes for patients who have LMD, new treatments need to reach the meninges and cerebrospinal fluid and interact with relevant molecular targets. Some of the agents currently in testing may contribute to this goal. To allow for better outcomes through earlier treatment, advances in diagnosis are needed. By using agents with higher therapeutic indices, in patients with a lower burden of disease (identified earlier with clinical or molecular markers) it should be possible to achieve gradual improvements in outcomes for patients suffering from this devastating disease.

A randomized trial on the efficacy of methylphenidate and modafinil for improving cognitive functioning and symptoms in patients with a primary brain tumor

Limited research is available regarding the efficacy of psychostimulants in treating cognitive function in primary brain tumor patients. An open-label, randomized, pilot trial examined both the general and differential efficacy of 4 weeks of methylphenidate (MPH) and modafinil (MOD) in 24 brain tumor patients. Participants completed cognitive tests and self-report measures of fatigue, sleep disturbance, mood and quality of life at baseline and after 4 weeks.Following stimulant treatment, there was evidence of a beneficial effect on test performance in speed of processing and executive function requiring divided attention. Patients with the greatest deficit in executive function at baseline appeared to derive the greatest benefit following stimulant therapy. Inconsistent, differential effects were found on a measure of attention in favor of MPH and on a measure of processing speed in favor of MOD. There was also evidence of a general beneficial effect on patient-reported measures of fatigue, mood, and quality of life, with no statistically significant differences between treatment arms in these measures over time. The results from this small pilot study should be interpreted with caution, but appear to warrant additional research, in larger study samples, targeting fatigue, processing speed and executive function, and exploring different doses of stimulants. Future studies may also wish to explore the specific patient factors that may be associated with responsiveness to psychostimulant treatment.

A phase I factorial design study of dose-dense temozolomide alone and in combination with thalidomide, isotretinoin, and/or celecoxib as postchemoradiation adjuvant therapy for newly diagnosed glioblastoma

External beam radiation therapy (XRT) with concomitant temozolomide and 6 cycles of adjuvant temozolomide (5/28-day schedule) improves survival in patients with newly diagnosed glioblastoma compared with XRT alone. Studies suggest that dose-dense temozolomide schedules and addition of cytostatic agents may further improve efficacy. This factorial design phase I/II protocol tested dose-dense temozolomide alone and combined with cytostatic agents. Patients with newly diagnosed glioblastoma received fractionated XRT to 60 Gy concomitant with temozolomide (75 mg/m²/day for 42 days). In the phase I portion, patients with stable disease or radiologic response 1 month after chemoradiation were randomized to adjuvant temozolomide alone (150 mg/m²/day, 7/14-day schedule) or with doublet combinations of thalidomide (400 mg/day), isotretinoin (100 mg/m²/day), and/or celecoxib (400 mg twice daily), or all 3 agents. Toxicity was assessed after 4 weeks. Among 54 patients enrolled (median age, 52 years; median Karnofsky performance status, 90), adjuvant treatment was not administered to 12 (22%), primarily because of disease progression (n = 10). All combinations were well tolerated. Grade 3/4 lymphopenia developed in 63% of patients, but no related infections occurred. One patient treated with temozolomide plus isotretinoin plus thalidomide had dose-limiting grade 3 fatigue and rash, and 1 patient receiving all 4 agents had dose-limiting grade 4 neutropenia. Venous thrombosis occurred in 7 patients, 4 of whom received thalidomide. From study entry, median survival was 20 months and the 2-year survival rate was 40%. Multiple cytostatic agents can be safely combined with dose-dense temozolomide. The factorial-based phase II portion of this study is currently ongoing.

Combination of 6-thioguanine, capecitabine, and celecoxib with temozolomide or lomustine for recurrent high-grade glioma

We evaluated the efficacy of temozolomide (TMZ) or lomustine (CCNU) in combination with 6-thioguanine, capecitabine, and celecoxib for the treatment of recurrent high-grade glioma. Forty-three patients with recurrent glioblastoma and 31 patients with recurrent anaplastic glioma (AG) were enrolled in this open-label, non-comparative study. Patients previously treated with TMZ received CCNU while all others received TMZ; all patients received 6-thioguanine, capecitabine, and celecoxib. Endpoints were 12-month progression-free survival (PFS) for patients with AG, 6-month PFS for patients with glioblastoma, duration of PFS, and MRI-based objective response rates. Results from the TMZ and CCNU treatment arms were combined in the final analysis because there was no statistically significant difference between them. Thirty-eight patients with glioblastoma were treated with the lomustine-based regimen, and five received the TMZ-based regimen. For the 43 glioblastoma patients, the objective response rate was 12 and 33% had stable disease; the 6-month PFS was 14% and median overall survival 32 weeks. For the 31 AG patients, the combined objective response rate was 26 and 42% had stable disease; the 12 month PFS was 44%. Treatment was reasonably well tolerated with hematological toxicity common and more frequent with CCNU than TMZ. The combination therapy with 6-thioguanine, capecitabine and celecoxib plus CCNU or TMZ does not appear to be more effective than other alkylating agent schedules for patients with recurrent glioblastoma. The combination, however, is promising for patients with recurrent high-grade AG.