Morris D. Groves

Phase I/II Study of Imatinib Mesylate for Recurrent Malignant Gliomas: North American Brain Tumor Consortium Study 99-08

Purpose: Phase I: To determine the maximum tolerated doses, toxicities, and pharmacokinetics of imatinib mesylate (Gleevec) in patients with malignant gliomas taking enzyme-inducing antiepileptic drugs (EIAED) or not taking EIAED. Phase II: To determine the therapeutic efficacy of imatinib. Experimental Design: Phase I component used an interpatient dose escalation scheme. End points of the phase II component were 6-month progression-free survival and response. Results: Fifty patients enrolled in the phase I component (27 EIAED and 23 non-EIAED). The maximum tolerated dose for non-EIAED patients was 800 mg/d. Dose-limiting toxicities were neutropenia, rash, and elevated alanine aminotransferase. EIAED patients received up to 1,200 mg/d imatinib without developing dose-limiting toxicity. Plasma exposure of imatinib was reduced by ∼68% in EIAED patients compared with non-EIAED patients. Fifty-five non-EIAED patients (34 glioblastoma multiforme and 21 anaplastic glioma) enrolled in the phase II component. Patients initially received 800 mg/d imatinib; 15 anaplastic glioma patients received 600 mg/d after hemorrhages were observed. There were 2 partial response and 6 stable disease among glioblastoma multiforme patients and 0 partial response and 5 stable disease among anaplastic glioma patients. Six-month progression-free survival was 3% for glioblastoma multiforme and 10% for anaplastic glioma patients. Five phase II patients developed intratumoral hemorrhages. Conclusions: Single-agent imatinib has minimal activity in malignant gliomas. CYP3A4 inducers, such as EIAEDs, substantially decreased plasma exposure of imatinib and should be avoided in patients receiving imatinib for chronic myelogenous leukemia and gastrointestinal stromal tumors. The evaluation of the activity of combination regimens incorporating imatinib is under way in phase II trials.

The Identification and Characterization of Breast Cancer CTCs Competent for Brain Metastasis

EpCAM− CTCs isolated from breast cancer patients express markers needed to promote brain metastasis. Cancer Cells in Blood, Directed to the Brain Circulating tumor cells (CTCs) have been touted as exciting sources of diagnostic information, where the number of CTCs may correlate with disease progression or treatment success. However, little is known about the biology of these cells and why they are in the bloodstream, mostly because technology has prevented their long-term culture and analysis outside the body. Now, Zhang et al. have figured out how to isolate CTCs from breast cancer patients and study their metastatic potential. Starting with cancer-associated circulating cells isolated from eight patients, the authors ultimately selected a population of CTCs from three patients that was EGFR+/HPSE+/ALDH1+/CD45−/EpCAM−. These CTCs were then grown as cell lines in culture, which allowed the authors to study their cancerous behavior in more detail. Zhang et al. hypothesized that a specific protein signature was present in these cells, essentially “telling” these cells to metastasize to the brain. After identifying the “brain metastasis selected markers (BMSMs)” as HER2+/EGFR+/HPSE+/Notch1+, the authors injected these selected patient CTCs into mice. By 6 weeks, between 60 and 80% of the BMSM CTCs metastasized to brain compared with only 0 to 20% for the parental CTC lines. This protein signature, derived from human cells and tested in mice, could possibly govern brain metastatic breast cancer in patients. The next step will be to validate the presence of this BMSM CTC signature in a large number of breast cancer patients with brain metastases, with the goal of not only predicting disease course but also better understanding metastatic cancer. 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.

Phase II Trial of Temozolomide Plus the Matrix Metalloproteinase Inhibitor, Marimastat, in Recurrent and Progressive Glioblastoma Multiforme

PURPOSE Novel therapies are needed for patients with recurrent glioblastoma multiforme (GBM). Because there is evidence that temozolomide (TMZ) has some activity in GBM and is well tolerated, and because of laboratory evidence that metalloproteinases are important in glioma cell invasion, the combination of TMZ and the matrix metalloproteinase inhibitor marimastat (MRM) in patients with recurrent GBM was studied. PATIENTS AND METHODS Forty-four patients with recurrent GBM after standard radiotherapy were enrolled. For 19 patients, this therapy was their first chemotherapy after tumor progression after irradiation; 25 others had received chemotherapy previously. TMZ 150 to 200 mg/m(2) days 1 to 5 and MRM 50 mg days 8 to 28 was administered at 28-day intervals for two cycles; then patients were reevaluated. Treatment continued until progression of tumor or toxicity developed. RESULTS Joint and tendon pain was the major therapy-related toxicity and was reported in 47% of patients. Five patients (11%) were removed from the study because of intolerable joint pain. For all patients, the progression-free survival (PFS) at 6 months was 39%. Median PFS was 17 weeks, median overall survival was 45 weeks, and 12-month PFS was 16%. CONCLUSION The combination of TMZ and MRM resulted in a PFS at 6 months that exceeded the literature target by 29%. This drug combination met phase II study criteria; further study in recurrent patients with GBM might be warranted. Further study of therapy-induced joint pain is necessary.

Diagnostic Tools for Neoplastic Meningitis: Detecting Disease, Identifying Patient Risk, and Determining Benefit of Treatment

Three methods are routinely used to diagnose neoplastic meningitis (NM): clinical signs and symptoms, cerebrospinal fluid (CSF) cytology, and magnetic resonance imaging (MRI) of the brain and spine. Clinical manifestations are often subtle or may be ascribed to other cancer complications, eg, treatment-related disorders or brain parenchymal metastases. CSF cytology has a high specificity (>95%), but its sensitivity is generally less than 50%. MRI sensitivity and specificity vary with the type of primary cancer; overall, MRI findings consistent with leptomeningeal disease are detected in fewer than 50% of NM patients. While most clinicians evaluate CSF cytology along with MRI and the clinical examination, underdiagnosis is a major problem, since many patients are both cytologically and radiographically negative. Failure to consider NM in the differential diagnosis magnifies the problem of underdiagnosis. CSF flow cytometry is particularly promising for evaluating NM from hematologic cancers, with a diagnostic sensitivity many fold greater than conventional cytology. Research has focused on identifying biochemical markers of tumor cells in the CSF. For example, molecules involved in CNS penetration (eg, matrix metalloproteinases and cathepsins), tumor cell tropism (eg, chemokines CXCL8 and CCL18), and angiogenesis (eg, vascular endothelial growth factor) are elevated in the CSF of patients with NM. Evidence that some tumor types are more likely to infiltrate the CNS also has stimulated research into primary tumor markers predictive of CNS metastases. At present, there is no tumor marker or patient characteristic that reliably predicts the development of NM, and diagnosis still relies on suggestive signs and symptoms, positive CSF cytology, or a consistent MRI-all late manifestations of NM. Until techniques capable of detecting NM early are developed, increased awareness of the disease and standardized evaluation are likely to have the greatest impact on improving diagnosis and implementing earlier treatment.

Phase I study of capecitabine in combination with temozolomide in the treatment of patients with brain metastases from breast carcinoma

A single‐institution Phase I clinical trial was conducted to determine the maximum tolerated dose (MTD) and define the safety profile of temozolomide and capecitabine when used in combination to treat brain metastases from breast cancer.

The prognostic impact of histology and 1p/19q status in anaplastic oligodendroglial tumors

It has been reported previously that the combined loss of chromosomal arms 1p and 19q is a significant predictor of outcome for patients with anaplastic oligodendroglial (AO) tumors and that such chromosomal loss correlates with classic histology in AO. The authors sought to determine whether histology was an equivalent or superior predictor of outcome compared with 1p/19q status in 131 patients with AO tumors.

Glutathione S-transferase polymorphisms and survival in primary malignant glioma

Purpose: The purpose of this research was to investigate the relationship between glutathione S-transferase (GST) polymorphisms and survival, and chemotherapy-related toxicity in 278 glioma patients. Experimental Design: We determined genetic variants for GSTM1, GSTT1, and GSTP1 enzymes by PCR and restriction fragment length polymorphisms. We conducted Kaplan-Meier and Cox-proportional hazard analyses to examine whether the GST polymorphisms are related to overall survival, and logistic regression analysis to explore whether the GST polymorphisms are associated with toxicity. Results: For patients with anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic oligoastrocytoma, and anaplastic ependymoma (n = 78), patients with GSTP1*A/*A-M1 null genotype survived longer than did the rest of the group (median survival “not achieved,” and 41 months, respectively; P = 0.06). Among patients treated with nitrosoureas (n = 108), those with GSTP1*A/*A and GSTM1 null genotype were 5.7 times (95% confidence interval, 0.9–37.4) more likely to experience an adverse event secondary to chemotherapy, compared with the others. Conclusions: In patients with anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic oligoastrocytoma, combination of germ-line GSTP1*A/*A and GSTM1 null genotype confers a survival advantage. Patients with this genotype also have an increased risk of adverse events secondary to chemotherapy that primarily comprised nitrosourea alkylating agents.

Prognostic factors and outcomes in patients with leptomeningeal melanomatosis

The purpose of this study was to describe a cohort of patients with leptomeningeal melanomatosis (LM) and to determine prognostic factors for outcomes in these patients. The primary hypothesis was that more extensive burden of CNS metastasis at the time of diagnosis of LM (as evidenced by imaging of the CNS parenchyma and meninges and cerebrospinal fluid [CSF] cytology status [positive versus negative]) correlates with poorer outcomes. The records of all patients with LM treated at M. D. Anderson Cancer Center between 1944 and 2002 were reviewed. Information on clinical course and outcomes was gathered. Univariate and multivariate analyses were performed on 110 patients using Cox proportional hazards regression analysis to examine the effects of possible predictive factors on survival. The overall median survival from LM diagnosis was 10 weeks, with a 95% confidence interval (CI) of 8-14 weeks. Eighty-six (78.2%) patients had cutaneous primary lesions, and 23 (20.9%) had melanoma of unknown primary site. The primary hypothesis was not proven. Neither the presence of parenchymal CNS metastases, nor greater imaging evidence of LM, nor positive CSF cytology at diagnosis correlated with survival outcomes. Univariate analyses revealed possible predictors of longer survival, including the presence of supratentorial or spinal LM on imaging at diagnosis versus its absence and any treatment of LM, whereas elevated serum lactate dehydrogenase at the time of LM diagnosis predicted shorter survival. Multivariate analysis revealed that a history of a primary melanoma lesion originating on the trunk predicted shorter survival after LM diagnosis (hazard ratio [HR] = 2.0, 95% CI = 1.0-3.8, p = 0.035), and treatment with intrathecal chemotherapy predicted longer survival (HR = 0.5, 95% CI = 0.4-0.8, p = 0.0036). The positive result with respect to treatment is unreliable due to the inability to remove treatment selection bias from the analysis. This retrospective analysis confirmed the dismal prognosis associated with LM. The amount of CNS tumor burden at the time of diagnosis of LM did not inversely correlate with survival outcomes, contrary to our hypothesis.

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.

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. Clin Cancer Res; 19(4); 900–8. ©2012 AACR.