Phase 1b trial of an ibrutinib-based combination therapy in recurrent/refractory CNS lymphoma.

Ibrutinib is a first-in-class inhibitor of Bruton tyrosine kinase (BTK) and has shown single-agent activity in recurrent/refractory central nervous system (CNS) lymphoma. Clinical responses are often transient or incomplete, suggesting a need for a combination therapy approach. We conducted a phase 1b clinical trial to explore the sequential combination of ibrutinib (560 or 840 mg daily dosing) with high-dose methotrexate (HD-MTX) and rituximab in patients with CNS lymphoma (CNSL). HD-MTX was given at 3.5 g/m2 every 2 weeks for a total of 8 doses (4 cycles; 1 cycle = 28 days). Ibrutinib was held on days of HD-MTX infusion and resumed 5 days after HD-MTX infusion or after HD-MTX clearance. Single-agent daily ibrutinib was administered continuously after completion of induction therapy until disease progression, intolerable toxicity, or death. We also explored next-generation sequencing of circulating tumor DNA (ctDNA) in cerebrospinal fluid (CSF) before and during treatment. The combination of ibrutinib, HD-MTX, and rituximab was tolerated with an acceptable safety profile (no grade 5 events, 3 grade 4 events). No dose-limiting toxicity was observed. Eleven of 15 patients proceeded to maintenance ibrutinib after completing 4 cycles of the ibrutinib/HD-MTX/rituximab combination. Clinical responses occurred in 12 of 15 patients (80%). Sustained tumor responses were associated with clearance of ctDNA from the CSF. This trial was registered at www.clinicaltrials.gov as #NCT02315326.

Preclinical and clinical evaluation of Buparlisib (BKM120) in recurrent/refractory Central Nervous System Lymphoma.

Central Nervous System (CNS) Lymphomas are aggressive brain tumors with limited treatment options. Targeting the phosphoinositide 3-kinase (PI3K) pathway yields promising responses across B-cell malignancies, but its therapeutic potential in CNS lymphomas remains unexplored. We present pre-clinical and clinical data on the pan-PI3K inhibitor Buparlisib in CNS lymphomas. In a primary CNS lymphoma-patient-derived cell line, we define the EC50. Four patients with recurrent CNS lymphoma were enrolled in a prospective trial. We evaluated Buparlisib plasma and cerebrospinal fluid pharmacokinetics, clinical outcomes, and adverse events. Treatment was well tolerated. Common toxicities include hyperglycemia, thrombocytopenia, and lymphopenia. The presence of Buparlisib in plasma and CSF was confirmed 2h post-treatment with a median CSF concentration below the EC50 defined in the cell line All four patients were evaluated for response and the median time to progression was 39 days. Buparlisib monotherapy did not lead to meaningful responses and the trial was prematurely stopped.Clinical Trial Registration: NCT02301364.

Efficacy and safety of bevacizumab in active brain metastases from non-small cell lung cancer.

Bevacizumab is effective for the treatment of non-small cell lung cancer (NSCLC). Ongoing trials are exploring the safety of bevacizumab in patients with inactive, previously treated brain metastases. However, bevacizumab safety and efficacy in the treatment of active brain metastases is unknown. Bevacizumab received accelerated FDA approval for progressive glioblastoma, a primary brain tumor, because of high response rates and low incidence of intracranial hemorrhage. We retrospectively identified patients treated with bevacizumab for active (treatment naïve or progressive) central nervous system (CNS) metastases from NSCLC. MRI scans performed at least 6 weeks after initiating bevacizumab were assessed for response. There were six patients, four women and two men with a median age of 60 years (range 59-77) at initiation of bevacizumab. Five patients had progressive CNS metastases despite prior treatment including surgery, radiotherapy, and/or chemotherapy; one patient had treatment-naïve brain metastases. Two patients had leptomeningeal metastases, isolated or coexistent with parenchymal brain metastases in one patient each. Bevacizumab was administered alone to one patient and in combination with various cytotoxic chemotherapies in the others. Toxicity included an asymptomatic (Grade 1) intra-tumoral hemorrhage which occurred in one of three patients receiving concurrent anticoagulation with bevacizumab. There was no recurrent CNS bleeding in two patients with a prior history of such hemorrhage. Best CNS response (RECIST) was partial in two, stable disease in three, and progression in one. Median progression-free survival (PFS) was 7.8 months and median overall survival (OS) was 14.1 months following initiation of bevacizumab. Clinical benefit was also observed in the form of improved symptoms and reduced corticosteroid requirements. Bevacizumab should be used with caution in patients with active CNS metastases pending additional safety data. This series suggests bevacizumab may be safe and effective for progressive brain metastases from NSCLC and deserves further study.

Genomic Correlates of Disease Progression and Treatment Response in Prospectively Characterized Gliomas.

PURPOSE: The genomic landscape of gliomas has been characterized and now contributes to disease classification, yet the relationship between molecular profile and disease progression and treatment response remain poorly understood.Experimental Design: We integrated prospective clinical sequencing of 1,004 primary and recurrent tumors from 923 glioma patients with clinical and treatment phenotypes. RESULTS: Thirteen percent of glioma patients harbored a pathogenic germline variant, including a subset associated with heritable genetic syndromes and variants mediating DNA repair dysfunctions (29% of the total) that were associated with somatic biallelic inactivation and mechanism-specific somatic phenotypes. In astrocytomas, genomic alterations in effectors of cell-cycle progression correlated with aggressive disease independent of IDH mutation status, arose preferentially in enhancing tumors (44% vs. 8%, P < 0.001), were associated with rapid disease progression following tumor recurrence (HR = 2.6, P = 0.02), and likely preceded the acquisition of alkylating therapy-associated somatic hypermutation. Thirty-two percent of patients harbored a potentially therapeutically actionable lesion, of whom 11% received targeted therapies. In BRAF-mutant gliomas, response to agents targeting the RAF/MEK/ERK signaling axis was influenced by the type of mutation, its clonality, and its cellular and genomic context. CONCLUSIONS: These data reveal genomic correlates of disease progression and treatment response in diverse types of glioma and highlight the potential utility of incorporating genomic information into the clinical decision-making for patients with glioma.

Bevacizumab in high-grade glioma patients following intraparenchymal hemorrhage.

BACKGROUND: Intraparenchymal hemorrhage (IPH) is a relative contraindication to bevacizumab therapy, an anti-vascular endothelial growth factor (VEGF) monoclonal antibody approved for the treatment of recurrent glioblastoma. However, in patients with symptomatic enhancing tumors and poor functional status, bevacizumab may be the only beneficial therapeutic option. METHODS: We retrospectively reviewed all patients with high-grade glioma who were treated between January 1, 2005 and December 31, 2014 with bevacizumab despite prior IPH. RESULTS: Eighteen patients met our study criteria. There were 12 women and 6 men with a median age of 56 years. Tumor types were glioblastoma (n = 15), anaplastic astrocytoma (n = 2), and anaplastic oligodendroglioma (n = 1). Seventeen patients had prior spontaneous intratumoral bleed (13 grade 1-2; 4 grade 3-4); the 1 remaining patient had a grade 3 bleed due to cerebral venous thrombosis. Among them, identifiable risk factors for hemorrhage were anti-VEGF therapy, anticoagulation use, thrombocytopenia, and hypertension; seven had no identifiable risk factors. The median duration from IPH to (re-)initiation of bevacizumab was 113 days (range 13-1367). Brain imaging performed prior to bevacizumab treatment showed persistent or evolving hemorrhage in 8 patients and complete resolution in 10 patients. With a median follow-up duration of 137 days after bevacizumab re-initiation, only 1 (6%) of the 18 patients re-bled; this patient had an anaplastic oligodendroglioma and developed a grade 2 intratumoral bleed after 3 doses of bevacizumab. CONCLUSIONS: The incidence of re-bleed is rare. Bevacizumab use was safe in patients with recurrent high-grade glioma following IPH for whom no other meaningful treatment options existed.

Ibrutinib Unmasks Critical Role of Bruton Tyrosine Kinase in Primary CNS Lymphoma.

Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor-associated protein CD79B. CD79B-mutant PCNSLs showed enrichment of mammalian target of rapamycin (mTOR)-related gene sets and increased staining with PI3K/mTOR activation markers. Inhibition of the PI3K isoforms p110α/p110δ or mTOR synergized with ibrutinib to induce cell death in CD79B-mutant PCNSL cells.Significance: Ibrutinib has substantial activity in patients with relapsed or refractory B-cell lymphoma of the CNS. Response rates in PCNSL were considerably higher than reported for diffuse large B-cell lymphoma outside the CNS, suggesting a divergent molecular pathogenesis. Combined inhibition of BTK and PI3K/mTOR may augment the ibrutinib response in CD79B-mutant human PCNSLs. Cancer Discov; 7(9); 1018-29. ©2017 AACR.See related commentary by Lakshmanan and Byrd, p. 940This article is highlighted in the In This Issue feature, p. 920.

Integration of 2-hydroxyglutarate-proton magnetic resonance spectroscopy into clinical practice for disease monitoring in isocitrate dehydrogenase-mutant glioma.

BACKGROUND: The majority of WHO grades II and III gliomas harbor a missense mutation in the metabolic gene isocitrate dehydrogenase (IDH) and accumulate the metabolite R-2-hydroxyglutarate (R-2HG). Prior studies showed that this metabolite can be detected in vivo using proton magnetic-resonance spectroscopy (MRS), but the sensitivity of this methodology and its clinical implications are unknown. METHODS: We developed an MR imaging protocol to integrate 2HG-MRS into routine clinical glioma imaging and examined its performance in 89 consecutive glioma patients. RESULTS: Detection of 2-hydroxyglutarate (2HG) in IDH-mutant gliomas was closely linked to tumor volume, with sensitivity ranging from 8% for small tumors (<3.4 mL) to 91% for larger tumors (>8 mL). In patients undergoing 2HG-MRS prior to surgery, tumor levels of 2HG corresponded with tumor cellularity but not with tumor grade or mitotic index. Cytoreductive therapy resulted in a gradual decrease in 2HG levels with kinetics that closely mirrored changes in tumor volume. CONCLUSIONS: Our study demonstrates that 2HG-MRS can be linked with routine MR imaging to provide quantitative measurements of 2HG in glioma and may be useful as an imaging biomarker to monitor the abundance of IDH-mutant tumor cells noninvasively during glioma therapy and disease monitoring.

Leptomeningeal metastases from leukemias and lymphomas.

Leptomeningeal dissemination of lymphoma and leukemia differs from that of solid tumors in a number of clinically important aspects. Specific histologic variants of lymphoma and leukemia have such a high incidence of cerebrospinal fluid (CSF) dissemination that assessing CSF cytology at diagnosis is crucial and prophylactic therapy of the CSF compartment is required. Furthermore, while the overall prognosis for patients with leptomeningeal metastases from leukemia and lymphoma is similar to solid tumors, selected patients have excellent response to therapy and attain durable remission. Therefore, aggressive treatment is warranted.

Neurologic complications of chemotherapy and radiation therapy.

PURPOSE OF REVIEW: Nervous system injury from cancer therapeutics is second only to myelosuppression as the most common toxicity caused by chemotherapy and radiation therapy. RECENT FINDINGS: Neurologic complications can be seen throughout the course of cancer diagnosis and treatment; some toxicities may not develop for years or even decades after completion of treatment, making diagnosis challenging. However, early recognition is critical as modification of therapeutic regimens can diminish long-term consequences of nervous system injury and improve a patient's quality of life. This article addresses the most common neurologic complications seen as a consequence of chemotherapy and radiation therapy in patients with systemic cancer. These common toxicities are likely to be seen with increasing frequency as patients with systemic cancer are living longer and receiving multiple courses of antineoplastic regimens, some of which are lifelong. SUMMARY: Neurotoxicity from cancer therapeutics is common, and early recognition is critical to proper diagnosis and intervention.

Phase II trial of sunitinib for recurrent and progressive atypical and anaplastic meningioma.

BACKGROUND: No proven effective medical therapy for surgery and radiation-refractory meningiomas exists. Sunitinib malate (SU011248) is a small-molecule tyrosine kinase inhibitor that targets vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor, abundant in meningiomas. METHODS: This was a prospective, multicenter, investigator-initiated single-arm phase II trial. The primary cohort enrolled patients with surgery and radiation-refractory recurrent World Health Organization (WHO) grades II-III meningioma. An exploratory cohort enrolled patients with WHO grade I meningioma, hemangiopericytoma, or hemangioblastoma. Sunitinib was administered at 50 mg/d for days 1-28 of every 42-day cycle. The primary endpoint was the rate of 6-month progression-free survival (PFS6), with secondary endpoints of radiographic response rate, safety, PFS, and overall survival. Exploratory objectives include analysis of tumoral molecular markers and MR perfusion imaging. RESULTS: Thirty-six patients with high-grade meningioma (30 atypical and 6 anaplastic) were enrolled. Patients were heavily pretreated (median number of 5 recurrences, range 2-10). PFS6 rate was 42%, meeting the primary endpoint. Median PFS was 5.2 months (95% CI: 2.8-8.3 mo), and median overall survival was 24.6 months (95% CI: 16.5-38.4 mo). Thirteen patients enrolled in the exploratory cohort. Overall toxicity included 1 grade 5 intratumoral hemorrhage, 2 grade 3 and 1 grade 4 CNS/intratumoral hemorrhages, 1 grade 3 and 1 grade 4 thrombotic microangiopathy, and 1 grade 3 gastrointestinal perforation. Expression of VEGFR2 predicted PFS of a median of 1.4 months in VEGFR2-negative patients versus 6.4 months in VEGFR2-positive patients (P = .005). CONCLUSION: Sunitinib is active in recurrent atypical/malignant meningioma patients. A randomized trial should be performed.

Phase II trial of continuous low-dose temozolomide for patients with recurrent malignant glioma.

BACKGROUND: In this phase II trial, we investigated the efficacy of a metronomic temozolomide schedule in the treatment of recurrent malignant gliomas (MGs). METHODS: Eligible patients received daily temozolomide (50 mg/m2) continuously until progression. The primary endpoint was progression-free survival rate at 6 months in the glioblastoma cohort (N = 37). In an exploratory analysis, 10 additional recurrent grade III MG patients were enrolled. Correlative studies included evaluation of 76 frequent mutations in glioblastoma (iPLEX assay, Sequenom) aiming at establishing the frequency of potentially "drugable" mutations in patients entering recurrent MG clinical trials. RESULTS: Among glioblastoma patients, median age was 56 y; median Karnofsky performance score (KPS) was 80; 62% of patients had been treated for ≥2 recurrences, including 49% of patients having failed bevacizumab. Treatment was well tolerated; clinical benefit (complete response + partial response + stable disease) was seen in 10 (36%) patients. Progression-free survival rate at 6 months was 19% and median overall survival was 7 months. Patients with previous bevacizumab exposure survived significantly less than bevacizumab-naive patients (median overall survival: 4.3 mo vs 13 mo; hazard ratio = 3.2; P = .001), but those patients had lower KPS (P = .04) and higher number of recurrences (P < .0001). Mutations were found in 13 of the 38 MGs tested, including mutations of EGFR (N = 10), IDH1 (N = 5), and ERBB2 (N = 1). CONCLUSIONS: In spite of a heavily pretreated population, including nearly half of patients having failed bevacizumab, the primary endpoint was met, suggesting that this regimen deserves further investigation. Results in bevacizumab-naive patients seemed particularly favorable, while results in bevacizumab-failing patients highlight the need to develop further treatment strategies for advanced MG. Clinical trials.gov identifier NCT00498927 (available at http://clinicaltrials.gov/ct2/show/NCT00498927).

Myelopathies in patients with cancer.

Myelopathy is a devastating neurologic complication of cancer. The resulting pain, paralysis, and incontinence can turn a patient with cancer from a functioning individual to one who is confined to a chair or bed. Early diagnosis and appropriate therapy can prevent or ameliorate these symptoms and improve both duration of survival and quality of life. Accurate neurologic assessment of patients is crucial for early diagnosis and correct therapy. Myelopathy in patients with cancer is not rare. Epidural spinal cord compression (SCC) affects an estimated 5% of patients with cancer; other disorders such as intramedullary spinal cord metastases, adverse effects of therapy, and paraneoplastic spinal cord syndromes, although less common, are equally devastating. Because of space limitations, this review addresses the pathophysiology, clinical findings, diagnosis, and treatment of only some of the myelopathies that affect patients with cancer (Table 1). Because of new data, epidural SCC and paraneoplastic syndromes are emphasized.

Randomized phase II trial of chemoradiotherapy followed by either dose-dense or metronomic temozolomide for newly diagnosed glioblastoma.

PURPOSE: Alternative dosing schedules of temozolomide may improve survival in patients with newly diagnosed glioblastoma (GBM) by increasing the therapeutic index, overcoming common mechanisms of temozolomide resistance, or both. The goal of this randomized phase II study was to evaluate two different temozolomide regimens in the adjuvant treatment of newly diagnosed GBM. PATIENTS AND METHODS: Adult patients with newly diagnosed GBM were randomly assigned to receive standard radiotherapy with concurrent daily temozolomide followed by six adjuvant cycles of either dose-dense (150 mg/m(2) days 1 to 7 and 15 to 21) or metronomic (50 mg/m(2) continuous daily) temozolomide. Maintenance doses of 13-cis-retinoic acid were then administered until tumor progression. The primary end point was overall survival (OS) at 1 year. Tumor tissue was assayed to determine O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. RESULTS: Eighty-five eligible patients were enrolled; 42 were randomly assigned to dose-dense and 43 to metronomic temozolomide. The 1-year survival rate was 80% for the dose-dense arm and 69% for the metronomic arm; median OS was 17.1 months (95% CI, 14.0 to 28.1 months) and 15.1 months (95% CI, 12.3 to 18.9 months), respectively. The most common toxicities were myelosuppression (leukopenia, neutropenia, and thrombocytopenia) and elevated liver enzymes. Pseudoprogression was observed in 37% of assessable patients and may have had an impact on estimates of progression-free survival (6.6 months in the dose-dense arm and 5.0 months in the metronomic arm). CONCLUSION: Both dose-dense and metronomic temozolomide regimens were well tolerated with modest toxicity. The dose-dense regimen appears promising, with 1-year survival of 80%.

A phase II trial of vinorelbine and intensive temozolomide for patients with recurrent or progressive brain metastases.

PURPOSE: To investigate the efficacy and safety of the combination of vinorelbine and intensive temozolomide for recurrent or progressive brain metastases from solid tumors. METHODS: Patients > or =18 years of age and with Karnofsky performance scale (KPS) > or = 60, adequate organ function and progressive or recurrent brain metastases were eligible. This was a phase II trial with 28-day cycles using temozolomide (150 mg/m(2), days 1-7 and 15-21) and vinorelbine 25 or 30 mg/m(2 )on days one and eight. The primary endpoint was objective radiographic response. RESULTS: Thirty-eight patients (15 men, 23 women) with a median age of 57 years (range, 39-75) and median KPS of 80 were enrolled. The primary tumor sites were lung (n = 20), breast (n = 11), colorectal (n = 2), kidney (n = 2), bladder (n = 1), endometrium (n = 1), head and neck (n = 1). Prior therapies included chemotherapy (97%), whole-brain radiation therapy (79%), brain metastasis resection (53%) and stereotatic radiosurgery (47%). Objective radiographic response rate was 5% (one complete response and one minor response); five patients had stable disease, 29 progressive disease and two patients were not evaluable. Twenty-nine patients (76%) have died and the median follow-up of survivors was six months. Median progression-free and overall survivals were 1.9 and 5 months, respectively. Grade 3/4 toxicities were mainly hematological and two patients discontinued the study due to myelosuppression. CONCLUSIONS: In this heavily pretreated population of patients with brain metastases, adding vinorelbine and increasing the intensity of temozolomide do not improve response rates compared to previous studies with single-agent temozolomide at standard doses.