Lakshmi Nayak

Epidemiology of Brain Metastases

Brain metastases are one of the most common neurologic complications of cancer. The incidence is 9%–17% based on various studies, although the exact incidence is thought to be higher. The incidence is increasing with the availability of improved imaging techniques which aid early diagnosis, and effective systemic treatment regimens which prolong life, thus allowing cancer to disseminate to the brain. Lung cancer, breast cancer, and melanoma are the most frequent to develop brain metastases, and account for 67%–80% of all cancers. Most patients with brain metastases have synchronous extracerebral metastases. Some patients present with no known primary cancer diagnosis. In children, brain metastases are rare; germ cell tumors, sarcomas, and neuroblastoma are the common offenders.

Orally administered colony stimulating factor 1 receptor inhibitor PLX3397 in recurrent glioblastoma: an Ivy Foundation Early Phase Clinical Trials Consortium phase II study

BACKGROUND The colony stimulating factor 1 receptor (CSF1R) ligands, CSF1 and interleukin-34, and the KIT ligand, stem cell factor, are expressed in glioblastoma (GB). Microglia, macrophages, blood vessels, and tumor cells also express CSF1R, and depletion of the microglia reduces tumor burden and invasive capacity. PLX3397 is an oral, small molecule that selectively inhibits CSF1R and KIT, penetrates the blood-brain barrier in model systems, and represents a novel approach for clinical development. METHODS We conducted a phase II study in patients with recurrent GB. The primary endpoint was 6-month progression-free survival (PFS6). Secondary endpoints included overall survival response rate, safety, and plasma/tumor tissue pharmacokinetics. Exploratory endpoints included pharmacodynamic measures of drug effect in blood and tumor tissue. RESULTS A total of 37 patients were enrolled, with 13 treated prior to a planned surgical resection (Cohort 1) and 24 treated without surgery (Cohort 2). PLX3397 was given at an oral dose of 1000 mg daily and was well tolerated. The primary efficacy endpoint of PFS6 was only 8.6%, with no objective responses. Pharmacokinetic endpoints revealed a median maximal concentration (Cmax) of 8090 ng/mL, with a time to attain Cmax of 2 hour in plasma. Tumor tissue obtained after 7 days of drug exposure revealed a median drug level of 5500 ng/g. Pharmacodynamic changes included an increase in colony stimulating factor 1 and reduced CD14(dim)/CD16+ monocytes in plasma compared with pretreatment baseline values. CONCLUSION PLX3397 was well tolerated and readily crossed the blood-tumor barrier but showed no efficacy. Additional studies are ongoing, testing combination strategies and potential biomarkers to identify patients with greater likelihood of response.

Recursive partitioning analysis of prognostic factors for glioblastoma patients aged 70 years or older.

The most‐used prognostic scheme for malignant gliomas included only patients aged 18 to 70 years. The purpose of this study was to develop a prognostic model for patients ≥70 years of age with newly diagnosed glioblastoma.

PD-1 blockade with nivolumab in relapsed/refractory primary central nervous system and testicular lymphoma

Primary central nervous system (CNS) lymphoma (PCNSL) and primary testicular lymphoma (PTL) are rare extranodal large B-cell lymphomas with similar genetic signatures. There are no standard-of-care treatment options for patients with relapsed and refractory PCNSL and PTL, and the overall prognosis is poor. PCNSLs and PTLs exhibit frequent 9p24.1 copy-number alterations and infrequent translocations of 9p24.1 and associated increased expression of the programmed cell death protein 1 (PD-1) ligands, PD-L1 and PD-L2. The activity of PD-1 blockade in other lymphomas with 9p24.1 alterations prompted us to test the efficacy of the anti-PD1 antibody, nivolumab, in 4 patients with relapsed/refractory PCNSL and 1 patient with CNS relapse of PTL. All 5 patients had clinical and radiographic responses to PD-1 blockade, and 3 patients remain progression-free at 13+ to 17+ months. Our data suggest that nivolumab is active in relapsed/refractory PCNSL and PTL and support further investigation of PD-1 blockade in these diseases.

Medical management of brain tumors and the sequelae of treatment

Patients with malignant brain tumors are prone to complications that negatively impact their quality of life and sometimes their overall survival as well. Tumors may directly provoke seizures, hypercoagulable states with resultant venous thromboembolism, and mood and cognitive disorders. Antitumor treatments and supportive therapies also produce side effects. In this review, we discuss major aspects of supportive care for patients with malignant brain tumors, with particular attention to management of seizures, venous thromboembolism, corticosteroids and their complications, chemotherapy including bevacizumab, and fatigue, mood, and cognitive dysfunction.

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.

Rare cell capture technology for the diagnosis of leptomeningeal metastasis in solid tumors

Objective: To evaluate the utility of rare cell capture technology (RCCT) in the diagnosis of leptomeningeal metastasis (LM) from solid tumors through identification of circulating tumor cells (CTCs) in the CSF. Methods: In this pilot study, CSF samples from 60 patients were analyzed. The main patient cohort consisted of 51 patients with solid tumors undergoing lumbar puncture for clinical suspicion of LM. Those patients underwent initial MRI evaluation and had CSF analyzed through conventional cytology and for the presence of CTCs using RCCT, based on immunomagnetic platform enrichment utilizing anti–epithelial cell adhesion molecule antibody-covered magnetic nanoparticles. An additional 9 patients with CSF pleocytosis but without solid tumors were separately analyzed to ensure accurate differentiation between CTCs and leukocytes. Results: Among the 51 patients with solid tumors, 15 patients fulfilled criteria for LM. CSF CTCs were found in 16 patients (median 20.7 CTCs/mL, range 0.13 to >150), achieving a sensitivity of 100% as compared with 66.7% for conventional cytology and 73.3% for MRI. One patient had a false-positive CSF CTC result (specificity = 97.2%); however, that patient eventually met LM criteria 6 months after the tap. CSF CTCs were not found in any of the additional 9 patients with CSF pleocytosis. Conclusion: RCCT is an accurate, novel method for the detection of LM in solid tumors, potentially providing earlier diagnostic confirmation and sparing patients from repeat lumbar punctures.

Prognosis and patterns of care in elderly patients with glioma.

The current study was conducted to evaluate the patterns of care and survival of older adults with oligodendroglioma (OLI) and astrocytoma (AST) from a large population‐based registry.

Extent of resection and overall survival for patients with atypical and malignant meningioma

The prognosis for patients with atypical and malignant meningioma is guarded; whether the extent of resection is associated with survival‐based outcomes in this population remains poorly defined. This study investigated the association between gross total resection (GTR) and all‐cause mortality in patients with atypical and malignant meningioma.

Multicenter phase II study of rituximab and temozolomide in recurrent primary central nervous system lymphoma

We initiated a prospective multicenter phase II trial using rituximab and temozolomide in immunocompetent patients with progressive or recurrent primary central nervous system lymphoma (PCNSL) based on activity observed in retrospective studies. Treatment consisted of an induction phase with rituximab (750 mg/m2) on days 1, 8, 15 and 22 and temozolomide (150 mg/m2) days 1–7 and 15–21, followed by six cycles of consolidation temozolomide (150–200 mg/m2 × 5/28 days), followed by maintenance with methylprednisolone (1 g IV every 28 days) until progression. Sixteen patients were enrolled, and a complete response was seen in 2/14 (14%) evaluable patients. The median progression-free survival was 7 weeks and median overall survival was not reached (median follow-up: 37 months). Treatment was well tolerated, but due to slow accrual and preliminary analysis suggesting futility, the trial was closed early. Given the overall modest activity, this regimen should be reserved for patients who are not candidates for other, more aggressive salvage treatments.