Challenges relating to solid tumour brain metastases in clinical trials, part 1: patient population, response, and progression. A report from the RANO group

Melanoma central nervous system metastases: current approaches, challenges, and opportunities

Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area.

Veliparib in combination with whole-brain radiation therapy for patients with brain metastases from non-small cell lung cancer: results of a randomized, global, placebo-controlled study

Veliparib is a potent, orally bioavailable, poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor that crosses the blood-brain barrier and has been shown to potentiate the effects of radiation in preclinical and early clinical studies. This phase 2, randomized, global study evaluated the efficacy and safety of veliparib in combination with whole-brain radiation therapy (WBRT) in patients with brain metastases from non-small cell lung cancer (NSCLC). Three-hundred and seven patients with brain metastases from NSCLC were randomized 1:1:1 to WBRT (30 Gy in 10 fractions) plus 50 mg veliparib twice daily (BID; n = 103), 200 mg veliparib BID (n = 102), or placebo BID (n = 102). Treatment began within 28 days of diagnosis. Tumor response and safety were assessed; the primary endpoint was overall survival (OS). Patients who received ≥1 dose of treatment were included in the safety analysis. All randomized patients were included in the efficacy endpoint analyses. Patient characteristics were well balanced between treatment arms. Median OS was 185 days for patients treated with WBRT plus placebo and 209 days for WBRT plus veliparib (50 or 200 mg). No statistically significant differences in OS, intracranial response rate, and time to clinical or radiographic progression between any of the treatment arms were noted. No differences were observed in adverse events (all grades) across treatment arms; nausea, fatigue, alopecia, and headache were the most commonly reported. No new safety signals were identified for veliparib. A significant unmet need for therapies that improve the outcomes of patients with brain metastases from NSCLC remains.

Response Assessment in Neuro-Oncology Criteria and Clinical Endpoints

The Response Assessment in Neuro-Oncology (RANO) Working Group is an international multidisciplinary group whose goal is to improve response criteria and define endpoints for neuro-oncology trials. The RANO criteria for high-grade gliomas attempt to address the issues of pseudoprogression, pseudoresponse, and nonenhancing tumor progression. Incorporation of advanced MR imaging may eventually help improve the ability of these criteria to define enhancing and nonenhancing disease better. The RANO group has also developed criteria for neurologic response and evaluation of patients receiving immunologic therapies. RANO criteria have been developed for brain metastases and are in progress for meningiomas, leptomeningeal disease, spinal tumors, and pediatric tumors.

Updates in the management of brain metastases

The clinical management/understanding of brain metastases (BM) has changed substantially in the last 5 years, with key advances and clinical trials highlighted in this review. Several of these changes stem from improvements in systemic therapy, which have led to better systemic control and longer overall patient survival, associated with increased time at risk for developing BM. Development of systemic therapies capable of preventing BM and controlling both intracranial and extracranial disease once BM are diagnosed is paramount. The increase in use of stereotactic radiosurgery alone for many patients with multiple BM is an outgrowth of the desire to employ treatments focused on local control while minimizing cognitive effects associated with whole brain radiotherapy. Complications from BM and their treatment must be considered in comprehensive patient management, especially with greater awareness that the majority of patients do not die from their BM. Being aware of significant heterogeneity in prognosis and therapeutic options for patients with BM is crucial for appropriate management, with greater attention to developing individual patient treatment plans based on predicted outcomes; in this context, recent prognostic models of survival have been extensively revised to incorporate molecular markers unique to different primary cancers.

FDA Approval: Alectinib for the Treatment of Metastatic, ALK-Positive Non-Small Cell Lung Cancer Following Crizotinib

On December 11, 2015, the FDA granted accelerated approval to alectinib (Alecensa; Genentech) for the treatment of patients with anaplastic lymphoma receptor tyrosine kinase (ALK)-positive, metastatic non-small cell lung cancer (NSCLC) who have progressed on or are intolerant to crizotinib. This approval was based on two single-arm trials including 225 patients treated with alectinib 600 mg orally twice daily. The objective response rates (ORR) by an independent review committee in these studies were 38% [95% confidence interval (CI), 28-49] and 44% (95% CI, 36-53); the median durations of response (DOR) were 7.5 months and 11.2 months. In a pooled analysis of 51 patients with measurable disease in the central nervous system (CNS) at baseline, the CNS ORR was 61% (95% CI, 46-74); the CNS DOR was 9.1 months. The primary safety analysis population included 253 patients. The most common adverse reactions were fatigue (41%), constipation (34%), edema (30%), and myalgia (29%). The most common laboratory abnormalities were anemia (56%), increased aspartate aminotransferase (51%), increased alkaline phosphatase (47%), increased creatine phosphokinase (43%), hyperbilirubinemia (39%), hyperglycemia (36%), increased alanine aminotransferase (34%), and hypocalcemia (32%). Dose reductions due to adverse reactions occurred in 12% of patients, whereas 27% of patients had alectinib dosing interrupted for adverse reactions. Permanent discontinuation of alectinib due to adverse reactions occurred in only 6% of patients. With the clinically meaningful ORR and DOR as well as the safety profile observed in these trials, alectinib was determined to have a favorable benefit-risk profile for the treatment of the indicated population. Clin Cancer Res; 22(21); 5171-6. ©2016 AACR.

Vascular Magnetic Resonance Imaging in Brain Tumors During Antiangiogenic Therapy--Are We There Yet?

Abnormal tumor vasculature is a potent mediator of treatment resistance because it results in heterogeneous perfusion, hypoxia, increased interstitial fluid pressure, and incomplete penetration of cytotoxic chemotherapies. Targeting this abnormal tumor vasculature is a promising therapeutic strategy, but results with antiangiogenic drugs in brain cancer have been mixed. Vasculature's response to treatment is a dynamic physiological process that can change rapidly throughout treatment, so it requires noninvasive techniques to serially monitor these changes in order to improve outcome. We review the role of vascular magnetic resonance imaging to measure tumor response to treatment and highlight opportunities and future avenues for expanding these promising techniques.

Descriptive statistical analysis of a real life cohort of 2419 patients with brain metastases of solid cancers

Aim

We provide a descriptive statistical analysis of baseline characteristics and the clinical course of a large real-life cohort of brain metastases (BM) patients.

Methods

We performed a retrospective chart review for patients treated for BM of solid cancers at the Medical University of Vienna between 1990 and 2011.

Results

We identified a total of 2419 BM patients (50.5% male, 49.5% female, median age 59 years). The primary tumour was lung cancer in 43.2%, breast cancer in 15.7%, melanoma in 16.4%, renal cell carcinoma in 9.1%, colorectal cancer in 9.3% and unknown in 1.4% of cases. Rare tumour types associated with BM included genitourinary cancers (4.1%), sarcomas (0.7%). gastro-oesophageal cancer (0.6%) and head and neck cancers (0.2%). 48.7% of patients presented with a singular BM, 27.7% with 2–3 and 23.5% with >3 BM. Time from primary tumour to BM diagnosis was shortest in lung cancer (median 11 months; range 1–162) and longest in breast cancer (median 44 months; 1–443; p<0.001). Multiple BM were most frequent in breast cancer (30.6%) and least frequent in colorectal cancer (8.5%; p<0.001). Patients with breast cancer had the longest median overall survival times (8 months), followed by patients with lung cancer (7 months), renal cell carcinoma (7 months), melanoma (5 months) and colorectal cancer (4 months; p<0.001; log rank test). Recursive partitioning analysis and graded prognostic assessment scores showed significant correlation with overall survival (both p<0.001, log rank test). Evaluation of the disease status in the past 2 months prior to patient death showed intracranial progression in 35.9%, extracranial progression in 27.5% and combined extracranial and intracranial progression in 36.6% of patients.

Conclusions

Our data highlight the heterogeneity in presentation and clinical course of BM patients in the everyday clinical setting and may be useful for rational planning of clinical studies.

Neurocognitive functioning and genetic variation in patients with primary brain tumours

Impairment of neurocognitive functioning is a common result of cerebral neoplasms and treatment, although there is substantial heterogeneity in the pattern and severity of neurocognitive dysfunction across individuals and tumour types. The effects of many clinical and patient characteristics on neurocognitive functioning have been documented, but little research has been devoted to understanding the effect of genetic variation on neurocognitive outcomes in patients with brain tumours. This Review highlights preliminary evidence that suggests an association between various genes and risk of adverse neurocognitive outcomes in patients with brain tumours. Studies include genes specific to neuronal function, and those associated with more systemic cellular regulation. Related scientific literature in other disease populations is briefly discussed to indicate additional candidate genes. We consider methodological issues central to the study of neurocognitive functioning and genetic associations for patients with brain tumours, and emphasise the need for future research integrating novel investigative techniques.

The Rationale for Targeted Therapies and Stereotactic Radiosurgery in the Treatment of Brain Metastases

Brain metastases are the most common intracranial malignancy. Many approaches, including radiation therapy, surgery, and cytotoxic chemotherapy, have been used to treat patients with brain metastases depending on the patient's disease burden and symptoms. However, stereotactic surgery (SRS) has revolutionized local treatment of brain metastases. Likewise, targeted therapies, including small-molecule inhibitors and monoclonal antibodies that target cancer cell metabolism or angiogenesis, have transformed managing systemic disease. Prospective data on combining these treatments for synergistic effect are limited, but early data show favorable safety and efficacy profiles. The combination of SRS and targeted therapy will further individualize treatment, potentially obviating the need for cytotoxic chemotherapy or whole-brain radiation. There is a great need to pursue research into these exciting modalities and novel combinations to further improve the treatment of patients with brain metastases. This article discusses reported and ongoing clinical trials assessing the safety and efficacy of targeted therapy during SRS.

IMPLICATIONS FOR PRACTICE

Treatment of patients with brain metastases requires a multidisciplinary approach. Stereotactic radiosurgery is increasingly used in the upfront setting to treat new brain metastasis. Targeted therapies have revolutionized systemic treatment of many malignancies and may sometimes be used as initial treatment in metastatic patients. There is sparse literature regarding safety and efficacy of combining these two treatment modalities. This article summarizes the supporting literature and highlights ongoing clinical trials in combining radiosurgery with targeted therapy.

FN14 and GRP94 expression are prognostic/predictive biomarkers of brain metastasis outcome that open up new therapeutic strategies

Brain metastasis is a devastating problem in patients with breast, lung and melanoma tumors. GRP94 and FN14 are predictive biomarkers over-expressed in primary breast carcinomas that metastasized in brain. To further validate these brain metastasis biomarkers, we performed a multicenter study including 318 patients with breast carcinomas. Among these patients, there were 138 patients with metastasis, of whom 84 had brain metastasis. The likelihood of developing brain metastasis increased by 5.24-fold (95%CI 2.83-9.71) and 2.55- (95%CI 1.52-4.3) in the presence of FN14 and GRP94, respectively. Moreover, FN14 was more sensitive than ErbB2 (38.27 vs. 24.68) with similar specificity (89.43 vs. 89.55) to predict brain metastasis and had identical prognostic value than triple negative patients (p < 0.0001). Furthermore, we used GRP94 and FN14 pathways and GUILD, a network-based disease-gene prioritization program, to pinpoint the genes likely to be therapeutic targets, which resulted in FN14 as the main modulator and thalidomide as the best scored drug. The treatment of mice with brain metastasis improves survival decreasing reactive astrocytes and angiogenesis, and down-regulate FN14 and its ligand TWEAK. In conclusion our results indicate that FN14 and GRP94 are prediction/prognosis markers which open up new possibilities for preventing/treating brain metastasis.

A Brief Report of the Status of Central Nervous System Metastasis Enrollment Criteria for Advanced Non-Small Cell Lung Cancer Clinical Trials: A Review of the ClinicalTrials.gov Trial Registry

INTRODUCTION

Central nervous system (CNS) metastases are common in non-small cell lung cancer (NSCLC), yet clinical trials of new drugs in advanced NSCLC have varying inclusion and exclusion criteria for CNS disease. The true extent of variation in CNS-related enrollment criteria in NSCLC clinical trials has not been documented.

METHODS

We performed a systematic search of the ClinicalTrials.gov website to characterize interventional drug trials enrolling adult patients with advanced NSCLC.

RESULTS

Of 413 open trials, 78 (19%) strictly excluded patients with leptomeningeal disease (LMD). Separate from LMD, patients with any history of CNS metastases were strictly excluded in 59 trials (14%), allowed after local treatment in 169 (41%), and allowed with no prior treatment in 106 (26%). No explicit mention of CNS disease was made in 79 trials (19%). In multivariate analysis looking at trial phase, location, sponsor, and treatment type, only sponsor was statistically significant, with pharmaceutical industry-sponsored trials having higher odds of excluding patients with brain metastases than did university or investigator-initiated trials (OR = 2.262, 95% confidence interval: 1.063-4.808, p = 0.0342) CONCLUSIONS: With 14% to 19% of trials excluding any history of LMD or CNS parenchymal metastatic disease and 41% of trials permitting CNS disease only after prior CNS-directed treatment, direct evidence of activity of a treatment on CNS disease cannot be reliably generated in most NSCLC trials. Given the high frequency of CNS disease in NSCLC and only sponsor being associated with specific CNS exclusion criteria, sponsors should consider tailoring trial designs to explore CNS benefit more explicitly.

PROFILE 1014: lessons for the new era of lung cancer clinical research

PROFILE 1014 compared crizotinib to up to six cycles of standard platinum-pemetrexed chemotherapy as the first line treatment of advanced anaplastic lymphoma kinase positive (ALK+) non-small cell lung cancer (NSCLC). Overall, PROFILE 1014 has taught us many valuable lessons about the natural history of ALK+ NSCLC, the effectiveness of key therapies and the positive ways in which clinical research in oncogene addicted subtypes of cancer continue to evolve. These lessons include (I) confirming the benefit of using personalized medicine approaches compared to chemotherapy that had already been established in EGFR mutant disease and in ALK+ disease in later lines of therapy; (II) demonstrating that molecular preselection can also affect outcomes from standard chemotherapy in addition to from targeted therapy. Specifically, the benefit of the control arm (platinum-pemetrexed), although inferior to that of crizotinib, was remarkable and expands the dataset on the increased sensitivity of ALK+ NSCLC to pemetrexed; (III) identifying the central nervous system (CNS) as a key battleground for metastatic NSCLC, especially for ALK+ disease. In PROFILE 1014 CNS time to progression (TTP) was included as a prominent secondary endpoint, which showed no difference between crizotinib and chemotherapy but all CNS lesions at baseline had to be both stable and treated, so any apparent stabilizing effect of the drug may be confounded. Ongoing studies with other ALK inhibitors vs. crizotinib that include untreated CNS diseases will provide greater clarity on the true effect of these drugs in the brain.

Response Assessment in Neuro-Oncology (RANO): more than imaging criteria for malignant glioma

The introduction of antiangiogenic therapies for the treatment of malignant glioma and the effect of these agents on standard imaging studies were the stimuli for forming a small group of investigators to critically evaluate the limitations of the Macdonald criteria in assessing response to treatment. The initial goal of this group was to highlight the challenges in accurately determining the efficacy of therapeutic interventions for malignant glioma and to develop new criteria that could be implemented in clinical care as well as in the design and conduct of clinical trials. This initial Response Assessment in Neuro-Oncology (RANO) effort started in 2008 and over the last 7 years, it has expanded to include a critical review of response assessment across several tumor types as well as endpoint selection and trial design to improve outcome criteria for neuro-oncological trials. In this paper, we review the overarching principles of the RANO initiative and the efforts to date. We also highlight the diverse and expanding efforts of the multidisciplinary groups of investigators who have volunteered their time as part of this endeavor.

Neurocognitive functioning and health-related quality of life in patients treated with stereotactic radiotherapy for brain metastases: a prospective study

BACKGROUND

Stereotactic radiotherapy (SRT) is expected to have a less detrimental effect on neurocognitive functioning and health-related quality of life (HRQoL) than whole-brain radiotherapy. To evaluate the impact of brain metastases and SRT on neurocognitive functioning and HRQoL, we performed a prospective study.

METHODS

Neurocognitive functioning and HRQoL of 97 patients with brain metastases were measured before SRT and 1, 3, and 6 months after SRT. Seven cognitive domains were assessed. HRQoL was assessed with the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and BN20 questionnaires. Neurocognitive functioning and HRQoL over time were analyzed with linear mixed models and stratified for baseline Karnofsky performance status (KPS), total metastatic volume, and systemic disease.

RESULTS

Median overall survival of patients was 7.7 months. Before SRT, neurocognitive domain and HRQoL scores were lower in patients than in healthy controls. At group level, patients worsened in physical functioning and fatigue at 6 months, while other outcome parameters of HRQoL and cognition remained stable. KPS < 90 and tumor volume >12.6 cm(3) were both associated with worse information processing speed and lower HRQoL scores over 6 months time. Intracranial tumor progression was associated with worsening of executive functioning and motor function.

CONCLUSIONS

Prior to SRT, neurocognitive functioning and HRQoL are moderately impaired in patients with brain metastases. Lower baseline KPS and larger tumor volume are associated with worse functioning. Over time, SRT does not have an additional detrimental effect on neurocognitive functioning and HRQoL, suggesting that SRT may be preferred over whole-brain radiotherapy.

Multicenter phase 2 study of patupilone for recurrent or progressive brain metastases from non-small cell lung cancer

BACKGROUND

Treatment options for patients with non-small cell lung cancer (NSCLC) with brain metastases are limited. Patupilone (EPO906), a blood-brain barrier-penetrating, microtubule-targeting, cytotoxic agent, has shown clinical activity in phase 1/2 studies in patients with NSCLC. This study evaluates the efficacy, pharmacokinetics, and safety of patupilone in NSCLC brain metastases.

METHODS

Adult patients with NSCLC and confirmed progressive brain metastases received patupilone intravenously at 10 mg/m(2) every 3 weeks. The primary endpoint of this multinomial 2-stage study combined early progression (EP; death or progression within 3 weeks) and progression-free survival at 9 weeks (PFS9w) to determine drug activity.

RESULTS

Fifty patients with a median age of 60 years (range, 33-74 years) were enrolled; the majority were men (58%), and most had received prior therapy for brain metastases (98%). The PFS9w rate was 36%, and the EP rate was 26%. Patupilone blood pharmacokinetic analyses showed mean areas under the concentration-time curve from time zero to 504 hours for cycles 1 and 3 of 1544 and 1978 ng h/mL, respectively, and a mean steady state distribution volume of 755 L/m(2) . Grade 3/4 adverse events (AEs), regardless of their relation with the study drug, included diarrhea (24%), pulmonary embolisms (8%), convulsions (4%), and peripheral neuropathy (4%). All patients discontinued the study drug: 31 (62%) for disease progression and 13 (26%) for AEs. Twenty-five of 32 deaths were due to brain metastases. The median time to progression and the overall survival were 3.2 and 8.8 months, respectively.

CONCLUSIONS

This is the first prospective study of chemotherapy for recurrent brain metastases from NSCLC. In this population, patupilone demonstrated activity in heavily treated patients.

Activity of T-DM1 in Her2-positive breast cancer brain metastases

Brain metastases (BM) are frequently diagnosed in metastatic Her2-positive breast cancer. Local treatment remains the standard of care but lapatinib plus capecitabine was recently established as systemic therapy option. Due to a disruption of the blood-brain/tumour-barrier at metastatic sites, even large molecules may penetrate into the central nervous system (CNS). Here, we report on the activity of T-DM1 in Her2-positive breast cancer BM. T-DM1 was administered at a dose of 3.6 mg once every 3 weeks as primary systemic therapy for BM or upon documented CNS progression after initial local treatment. Thus, this study allowed for the appraisal of T-DM1 activity in BM. Restaging was conducted every 12 weeks with MRI or whenever symptoms of disease progression occurred. Ten patients were included; in two asymptomatic subjects, T-DM1 was administered as primary therapy, while eight had progressive BM. All patients had received prior treatment with trastuzumab, six had already received lapatinib, and three pertuzumab as well. Three patients had partial remission of BM, and two patient had stable disease lasting for ≥6 months; two further patients had stable disease for <6 months while three progressed despite treatment. At 8.5 months median follow-up, intracranial PFS was 5 months, and median OS from initiation of T-DM1 was not reached. Local treatment of BM remains the standard of care; lapatinib plus capecitabine is currently the best established systemic therapy option. Still, T-DM1 apparently offers relevant clinical activity in BM and further investigation is warranted.

The future of targeted therapies for brain metastases

Brain metastases (BM) are an increasing challenge in the management of patients with advanced cancer. Treatment options for BM are limited and mainly focus on the application of local therapies. Systemic therapies including targeted therapies are only poorly investigated, as patients with BM were frequently excluded from clinical trials. Several targeted therapies have shown promising activity in patients with BM. In the present review we discuss existing and emerging targeted therapies for the most frequent BM primary tumor types. We focus on challenges in the conduction of clinical trials on targeted therapies in BM patients such as patient selection, combination with radiotherapy, the obstacles of the blood–brain barrier and the definition of study end points.

PET imaging for brain tumor diagnostics

PURPOSE OF REVIEW

Brain tumors differ in histology, biology, prognosis and treatment options. Although structural magnetic resonance is still the gold standard for morphological tumor characterization, molecular imaging has gained an increasing importance in assessment of tumor activity and malignancy.

RECENT FINDINGS

Amino acid PET is frequently used for surgery and biopsy planning as well as therapy monitoring in suspected primary brain tumors as well as metastatic lesions, whereas 18F-fluorodeoxyglucose (18F-FDG) remains the tracer of choice for evaluation of patients with primary central nervous system lymphoma. Application of somatostatin receptor ligands has improved tumor delineation in skull base meningioma and concurrently opened up new treatment possibilities in recurrent or surgically not assessable tumors.Recent development focuses on the implementation of hybrid PET/MRI as well as on the development of new tracers targeting tumor hypoxia, enzymes involved in neoplastic metabolic pathways and the combination of PET tracers with therapeutic agents.

SUMMARY

Implementation of molecular imaging in the clinical routine continues to improve management in patients with brain tumors. However, more prospective large sample studies are needed to validate the additional informative value of PET.

Comparative Effectiveness Analysis of Treatment Options for Single Brain Metastasis

BACKGROUND

Brain metastases (BMs) occur in up to 30% of patients with cancer. Treatments include surgery, whole-brain radiotherapy (WBRT), and stereotactic radiosurgery (SRS), alone or in combination. Although guidelines exist, data to inform individualized approaches to therapy remain sparse. We sought to compare semiquantitatively the effectiveness of various modalities in the treatment of single brain metastasis.

METHODS

We performed a comparative effectiveness analysis (CEA) that integrated efficacy, cost, and quality of life (QoL) data for alternate BM treatments. Efficacy data were obtained from a comprehensive review of current literature. Cost estimates were based on publicly available data. QoL data included the Karnofsky Performance Status (KPS) and other questionnaires. Six treatment strategies using combinations of surgery, WBRT, and SRS were compared with decision tree software.

RESULTS

The clinical efficacy, cost, and QoL effects of each strategy were scored semiquantitatively. We constructed a model to integrate individual preferences regarding the relative importance of efficacy, QoL, and cost to provide personalized rankings of the effectiveness of each strategy.

CONCLUSION

The choice of strategy must be individualized for patients with a single BM. Our CEA and decision model combines empirical data with patient priorities to produce a ranking of alternate management strategies.

Response assessment criteria for brain metastases: proposal from the RANO group

CNS metastases are the most common cause of malignant brain tumours in adults. Historically, patients with brain metastases have been excluded from most clinical trials, but their inclusion is now becoming more common. The medical literature is difficult to interpret because of substantial variation in the response and progression criteria used across clinical trials. The Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) working group is an international, multidisciplinary effort to develop standard response and progression criteria for use in clinical trials of treatment for brain metastases. Previous efforts have focused on aspects of trial design, such as patient population, variations in existing response and progression criteria, and challenges when incorporating neurological, neuro-cognitive, and quality-of-life endpoints into trials of patients with brain metastases. Here, we present our recommendations for standard response and progression criteria for the assessment of brain metastases in clinical trials. The proposed criteria will hopefully facilitate the development of novel approaches to this difficult problem by providing more uniformity in the assessment of CNS metastases across trials.

Radiation necrosis presenting as pseudoprogression (PsP) during alectinib treatment of previously radiated brain metastases in ALK-positive NSCLC: Implications for disease assessment and management

OBJECTIVES

Radiation necrosis presenting as pseudoprogression (PsP) is relatively common after radiation and temozolomide (TMZ) treatment in glioblastoma multiforme (GBM), especially among patients with GBM that harbors intrinsic increased responsiveness to TMZ (methylated O6-methylguanine-DNA methyltransferase [MGMT] promoter). Alectinib is a second generation ALK inhibitor that has significant CNS activity against brain metastases in anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

We report 2 ALK+ NSCLC patients who met RECIST criteria for progressive disease by central radiologic review due to increased in size from increased contrast enhancement in previously stereotactically radiated brain metastases with ongoing extra-cranial response to alectinib. In both patients alectinib was started within 4 months of completing stereotactic radiosurgery (SRS). The enlarging lesions in both patients were resected and found to have undergone extensive necrosis with no residual tumor pathologically. PsP was incorrectly classified as progressive disease even by central independent imaging review.

CONCLUSIONS

Treatment-related necrosis of previously SRS-treated brain metastasis during alectinib treatment can present as PsP. It may be impossible to distinguish PsP from true disease progression without a pathologic examination from resected sample. High degree of clinical suspicion, close monitoring and more sensitive imaging modalities may be needed to distinguish PsP versus progression in radiated brain lesions during alectinib treatment especially if there is no progression extra-cranially.

Bevacizumab preconditioning followed by Etoposide and Cisplatin is highly effective in treating brain metastases of breast cancer progressing from whole-brain radiotherapy

PURPOSE

We hypothesized that a window period between bevacizumab and cytotoxic agents may enhance drug delivery into tumor tissue through bevacizumab-induced vascular normalization in patients with brain metastases of breast cancer (BMBC).

EXPERIMENTAL DESIGN

A single-arm phase II study was conducted in which BMBC patients refractory to whole-brain radiotherapy (WBRT) were enrolled. In a 21-day cycle, patients received bevacizumab (15 mg/kg) on day 1, which, with a 1-day window period, was followed by etoposide (70 mg/m(2)/day; days 2-4) and cisplatin (70 mg/m(2); day 2; BEEP regimen). The BEEP regimen was administered for a maximum of 6 cycles. The primary endpoint was the central nervous system (CNS)-objective response rate according to volumetric response criteria.

RESULTS

A total of 35 patients were enrolled between January 2011 and January 2013. The median age was 54.3 years (range, 33-75); 19 patients (54.3%) had an Eastern Cooperative Oncology Group performance status of 2 or 3. Twenty-seven patients [77.1%; 95% confidence interval (CI), 59.9-89.6] achieved a CNS-objective response, including 13 patients (37.1%) with a ≥80% volumetric reduction of CNS lesions. With a median follow-up of 16.1 months, the median CNS progression-free survival and overall survival times were 7.3 months (95% CI, 6.5-8.1) and 10.5 months (95% CI, 7.8-13.2), respectively. Common grade 3 or 4 toxicities included neutropenia (30.8%) and infection (21.3%).

CONCLUSIONS

By administering bevacizumab 1 day before etoposide and cisplatin, the BEEP regimen appeared highly effective in BMBC refractory to WBRT. Further study of vascular normalization window concept is warranted.

Comparison Between Surgical Resection and Stereotactic Radiosurgery in Patients with a Single Brain Metastasis from Non-Small Cell Lung Cancer

BACKGROUND

The management of patients with single brain metastasis (BM) from non-small cell lung cancer (NSCLC) is controversial. Surgical resection (SR) with adjuvant irradiation and stereotactic radiosurgery (SRS) are performed in the treatment of such lesions. This study compared both modalities in terms of tumor control and survival.

METHODS

During the period 2004-2011, 115 patients with single BM from NSCLC were treated with SR or SRS at our institution. Median patient age was 61 years. SR was performed in 43 patients, and SRS was performed in 72 patients. Most patients who underwent SR had adjuvant irradiation. Of patients, 63% in the SR group and 56% in the SRS group had synchronous presentation of BM and lung primary tumor. Thoracic disease was managed with curative intent in 60% of patients in the SR group compared with 50% of patients in the SRS group.

RESULTS

Median follow-up was 10.2 months. Local control was 72% in patients in the SR group and 79% in patients in the SRS group (P = 0.992). Median survival for patients in the SR group was 13.3 months, and median survival for patients in the SRS group was 7.8 months (P = 0.047). Multivariate analyses revealed aggressive treatment of the primary NSCLC as an independent factor associated with prolonged survival in patients undergoing SR. In the SRS group, patients with metachronous metastasis showed a better prognosis. Metachronous presentation was associated with more aggressive management of the primary tumor.

CONCLUSIONS

In this study, patients with single BM undergoing SR had a survival advantage. However, because SR and SRS achieved comparable local control of BM, patients receiving SRS should benefit from an equally aggressive treatment of the primary NSCLC, as thoracic management was the most important predictor of survival.

Whole brain irradiation with hippocampal sparing and dose escalation on multiple brain metastases: Local tumour control and survival

PURPOSE

Hippocampal-avoidance whole brain radiotherapy (HA-WBRT) for multiple brain metastases may prevent treatment-related cognitive decline, compared to standard WBRT. Additionally, simultaneous integrated boost (SIB) on individual metastases may further improve the outcome. Here, we present initial data concerning local tumour control (LTC), intracranial progression-free survival (PFS), overall survival (OS), toxicity and safety for this new irradiation technique.

METHODS AND MATERIALS

Twenty patients, enrolled between 2011 and 2013, were treated with HA-WBRT (30 Gy in 12 fractions, D98% to hippocampus ≤ 9 Gy) and a SIB (51 Gy) on multiple (2-13) metastases using a volumetric modulated arc therapy (VMAT) approach based on 2-4 arcs. Metastases were evaluated bidimensionally along the two largest diameters in contrast-enhanced three-dimensional T1-weighed MRI.

RESULTS

Median follow-up was 40 weeks. The median time to progression of boosted metastases has not been reached yet, corresponding to a LTC rate of 73%. Median intracranial PFS was 40 weeks, corresponding to a 1-year PFS of 45.3%. Median OS was 71.5 weeks, corresponding to a 1-year OS of 60%. No obvious acute or late toxicities grade > 2 (NCI CTCAE v4.03) were observed. Dmean to the bilateral hippocampi was 6.585 Gy ± 0.847 (α/β = 2 Gy). Two patients developed a new metastasis in the area of hippocampal avoidance.

CONCLUSION

HA-WBRT (simultaneous integrated protection, SIP) with SIB to metastases is a safe and tolerable regime that shows favorable LTC for patients with multiple brain metastases, while it has the potential to minimize the side-effect of cognitive deterioration.

Meningiomas: knowledge base, treatment outcomes, and uncertainties. A RANO review

Evolving interest in meningioma, the most common primary brain tumor, has refined contemporary management of these tumors. Problematic, however, is the paucity of prospective clinical trials that provide an evidence-based algorithm for managing meningioma. This review summarizes the published literature regarding the treatment of newly diagnosed and recurrent meningioma, with an emphasis on outcomes stratified by WHO tumor grade. Specifically, this review focuses on patient outcomes following treatment (either adjuvant or at recurrence) with surgery or radiation therapy inclusive of radiosurgery and fractionated radiation therapy. Phase II trials for patients with meningioma have recently completed accrual within the Radiation Therapy Oncology Group and the European Organisation for Research and Treatment of Cancer consortia, and Phase III studies are being developed. However, at present, there are no completed prospective, randomized trials assessing the role of either surgery or radiation therapy. Successful completion of future studies will require a multidisciplinary effort, dissemination of the current knowledge base, improved implementation of WHO grading criteria, standardization of response criteria and other outcome end points, and concerted efforts to address weaknesses in present treatment paradigms, particularly for patients with progressive or recurrent low-grade meningioma or with high-grade meningioma. In parallel efforts, Response Assessment in Neuro-Oncology (RANO) subcommittees are developing a paper on systemic therapies for meningioma and a separate article proposing standardized end point and response criteria for meningioma.

[Advances in treatment of brain metastases from primary non-small cell lung cancer]

脑是非小细胞肺癌常见的转移部位，手术和放疗是以往脑转移治疗的基石，但近年来随着对肿瘤发生发展机制的认识深化，靶向治疗在脑转移治疗中开始崭露头角。本文主要针对一些相关热点问题如脑转移治疗手段等（手术、放疗、化疗、靶向治疗）进行简要述评。

Microvesicles as a Biomarker for Tumor Progression versus Treatment Effect in Radiation/Temozolomide-Treated Glioblastoma Patients

The standard of care for glioblastoma (GB) is surgery followed by concurrent radiation therapy (RT) and temozolomide (TMZ) and then adjuvant TMZ. This regime is associated with increased survival but also increased occurrence of equivocal imaging findings, e.g., tumor progression (TP) versus treatment effect (TE), which is also referred to as pseudoprogression (PsP). Equivocal findings make decisions regarding further treatment difficult and often delayed. Because none of the current imaging assays have proven sensitive and specific for differentiation of TP versus TE/PsP, we investigated whether blood-derived microvesicles (MVs) would be a relevant assay. METHODS: 2.8 ml of citrated blood was collected from patients with GB at the time of their RT simulation, at the end of chemoradiation therapy (CRT), and multiple times following treatment. MVs were collected following multiple centrifugations (300g, 2500g, and 15,000g). The pellet from the final spin was analyzed using flow cytometry. A diameter of approximately 300 nm or greater and Pacific Blue–labeled Annexin V positivity were used to identify the MVs reported herein. RESULTS: We analyzed 19 blood samples from 11 patients with GB. MV counts in the patients with stable disease or TE/PsP were significantly lower than patients who developed TP (P = .014). CONCLUSION: These preliminary data suggest that blood analysis for MVs from GB patients receiving CRT may be useful to distinguish TE/PsP from TP. MVs may add clarity to standard imaging for decision making in patients with equivocal imaging findings.

Brain metastasis and treatment

Despite major therapeutic advances in the management of patients with systemic malignancies, management of brain metastases remains a significant challenge. These patients often require multidisciplinary care that includes surgical resection, radiation therapy, chemotherapy, and targeted therapies. Complex decisions about the sequencing of therapies to control extracranial and intracranial disease require input from neurosurgeons, radiation oncologists, and medical/neuro-oncologists. With advances in understanding of the biology of brain metastases, molecularly defined disease subsets and the advent of targeted therapy as well as immunotherapeutic agents offer promise. Future care of these patients will entail tailoring treatment based on host (performance status and age) and tumor (molecular cytogenetic characteristics, number of metastases, and extracranial disease status) factors. Considerable work involving preclinical models and better clinical trial designs that focus not only on effective control of tumor but also on quality of life and neurocognition needs to be done to improve the outcome of these patients.

Functional dynamic contrast-enhanced magnetic resonance imaging in an animal model of brain metastases: a pilot study

Background

Brain metastasis is a common disease with a poor prognosis. The purpose of this study is to test feasibility and safety of the animal models for brain metastases and to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to enhance detection of brain metastases.

Methods

With approval from the institutional animal ethics committee, 18 New Zealand rabbits were randomly divided into three groups: Group A received an intra-carotid infusion (ICI) of mannitol followed by VX2 cells; group B received successive ICI of mannitol and heparin followed by VX2 cells; and group C received an ICI of normal saline. The survival rate and clinical symptoms were recorded after inoculation. After two weeks, conventional MRI and DCE-MRI were performed using 3.0 Tesla scanner. The number of tumors and detection rate were analyzed. After MRI measurements, the tumors were stained with hematoxylin-eosin.

Results

No rabbits died during the procedure. The rabbits had common symptoms, including loss of appetite, lassitude and lethargy, etc. at 10.8±1.8 days and 8.4±1.5 days post-inoculation in group A and B, respectively. Each animal in groups A and B re-gained the lost weight within 14 days. Brain metastases could be detected by MRI at 14 days post-inoculation in both groups A and B, with metastases manifesting as nodules in the brain parenchyma and thickening in the meninges. DCE-MRI increased the total detection of tumors compared to non-contrast MRI (P<0.05). The detection rates of T1-weighted image, T2-weighted image and DCE-MRI were 12%, 32% and 100%, respectively (P<0.05). Necropsy revealed nodules or thickening meninges in the gross samples and VX2 tumor cytomorphologic features in the slides, which were consistent with the MRI results.

Conclusions

The VX2 rabbit model of brain metastases is feasible, as verified by MRI and pathologic findings, and may be a suitable platform for future studies of brain metastases. Functional DCE-MRI can be used to evaluate brain metastases in a rabbit model.

Vessel caliber--a potential MRI biomarker of tumour response in clinical trials

Our understanding of the importance of blood vessels and angiogenesis in cancer has increased considerably over the past decades, and the assessment of tumour vessel calibre and structure has become increasingly important for in vivo monitoring of therapeutic response. The preferred method for in vivo imaging of most solid cancers is MRI, and the concept of vessel-calibre MRI has evolved since its initial inception in the early 1990s. Almost a quarter of a century later, unlike traditional contrast-enhanced MRI techniques, vessel-calibre MRI remains widely inaccessible to the general clinical community. The narrow availability of the technique is, in part, attributable to limited awareness and a lack of imaging standardization. Thus, the role of vessel-calibre MRI in early phase clinical trials remains to be determined. By contrast, regulatory approvals of antiangiogenic agents that are not directly cytotoxic have created an urgent need for clinical trials incorporating advanced imaging analyses, going beyond traditional assessments of tumour volume. To this end, we review the field of vessel-calibre MRI and summarize the emerging evidence supporting the use of this technique to monitor response to anticancer therapy. We also discuss the potential use of this biomarker assessment in clinical imaging trials and highlight relevant avenues for future research.

The evolving role of neurological imaging in neuro-oncology

Neuroimaging has played a critical role in the management of patients with neurological disease, since the first ventriculogram was performed in 1918 by Walter Dandy (Mezger et al. Langenbecks Arch Surg 398(4):501-514, 2013). Over the last century, technology has evolved significantly, and within the last decade, the role of imaging in the management of patients with neuro-oncologic disease has shifted from a tool for gross identification of intracranial pathology, to an integral part of real-time neurological surgery. Current neurological imaging provides detailed information about anatomical structure, neurological function, and metabolic and metabolism-important characteristics that help clinicians and surgeons non-invasively manage patients with brain tumors. It is valuable to review the evolution of neurological imaging over the past several decades, focusing on its role in the management of patients with intracranial tumors. Novel neuro-imaging tools and developing technology with the potential to further transform clinical practice will be discussed, as will the key role neurological imaging plays in neurosurgical planning and intraoperative navigation. With increasingly complex imaging modalities creating growing amounts of raw data, validation of techniques, data analysis, and integrating various pieces of imaging data into individual patient management plans, remain significant challenges for clinicians. We thus suggest mechanisms that might ultimately allow for evidence based integration of imaging in the management of patients with neuro-oncologic disease.

The value of 4-month neurocognitive function as an endpoint in brain metastases trials

To investigate whether the neurocognitive function at 4 months could be a relevant primary endpoint in clinical trials dealing with brain metastases, we created a Japanese neurocognitive battery and examined the changes in patients' neurocognitive function for 1 year after their brain radiotherapy. In this prospective pilot study, we enrolled 27 patients (20 patients who received whole-brain radiation therapy [WBRT] and seven who received stereotactic irradiation [STI] alone) between March 2009 and December 2010. The follow-up neurocognitive data at 4, 8 and 12 months were available in 22 (17 WBRT, 5 STI), 19 patients (14 WBRT, 5 STI) and 13 patients (9 WBRT, 4 STI), respectively. Among the patients who received WBRT, significant deterioration in delayed memory compared to the baseline (p = 0.04) was observed at 4 months, and at 8 months, significant improvements were observed in immediate memory compared to the baseline (p = 0.008) and 4-months scores (p = 0.005). At 12 months, however, the immediate memory scores had returned to the baseline. Similar trends were observed in other functions (delayed memory, attention and executive functions). In these patients, the correlations between 4-months scores of neurocognitive functions and 12-months scores were significant in immediate memory (γ = 0.68, p = 0.004), delayed memory (γ = 0.738, p = 0.023) and attention (γ = 0.817, p = 0.007). Among the patients who received STI, no significant changes were observed in any functions. These results suggest that 4-months changes in neurocognitive functions were transient but could also be a premonitory index for predicting the neurocognitive function 1 year or later after brain radiation therapy.

CNS metastases in breast cancer: old challenge, new frontiers

Despite major therapeutic advances in the management of patients with breast cancer, central nervous system (CNS) metastases remain an intractable problem, particularly in patients with metastatic HER2-positive and triple-negative breast cancer. As systemic therapies to treat extracranial disease improve, some patients are surviving longer, and the frequency of CNS involvement seems to be increasing. Furthermore, in the early-stage setting, the CNS remains a potential sanctuary site for relapse. This review highlights advances in the development of biologically relevant preclinical models, including the development of brain-tropic cell lines for testing of agents to prevent and treat brain metastases, and summarizes our current understanding of the biology of CNS relapse. From a clinical perspective, a variety of therapeutic approaches are discussed, including methods to improve drug delivery, novel cytotoxic agents, and targeted therapies. Challenges in current trial design and endpoints are reviewed. Finally, we discuss promising new directions, including novel trial designs, correlative imaging techniques, and enhanced translational opportunities.

Acquired resistance to TKIs in solid tumours: learning from lung cancer

The use of advanced molecular profiling to direct the use of targeted therapy, such as tyrosine kinase inhibitors (TKIs) for patients with advanced-stage non-small-cell lung cancer (NSCLC), has revolutionized the treatment of this disease. However, acquired resistance, defined as progression after initial benefit, to targeted therapies inevitably occurs. This Review explores breakthroughs in the understanding and treatment of acquired resistance in NSCLC, focusing on EGFR mutant and ALK rearrangement-positive disease, which may be relevant across multiple different solid malignancies with oncogene-addicted subtypes. Mechanisms of acquired resistance may be pharmacological (that is, failure of delivery of the drug to its target) or biological, resulting from evolutionary selection on molecularly diverse tumours. A number of clinical approaches can maintain control of the disease in the acquired resistance setting, including the use of radiation to treat isolated areas of progression and adding or switching to cytotoxic chemotherapy. Furthermore, novel approaches that have already proven successful include the development of second-generation and third-generation inhibitors and the combination of some of these inhibitors with antibodies directed against the same target. With our increased understanding of the spectrum of acquired resistance, major changes in how we conduct clinical research in this setting are now underway.

High Resolution Imaging of Viscoelastic Properties of Intracranial Tumours by Multi-Frequency Magnetic Resonance Elastography

PURPOSE

In recent years Magnetic Resonance Elastography (MRE) emerged into a clinically applicable imaging technique. It has been shown that MRE is capable of measuring global changes of the viscoelastic properties of cerebral tissue. The purpose of our study was to evaluate a spatially resolved three-dimensional multi-frequent MRE (3DMMRE) for assessment of the viscoelastic properties of intracranial tumours.

METHODS

A total of 27 patients (63 ± 13 years) were included. All examinations were performed on a 3.0 T scanner, using a modified phase-contrast echo planar imaging sequence. We used 7 vibration frequencies in the low acoustic range with a temporal resolution of 8 dynamics per wave cycle. Post-processing included multi-frequency dual elasto-visco (MDEV) inversion to generate high-resolution maps of the magnitude |G*| and the phase angle φ of the complex valued shear modulus.

RESULTS

The tumour entities included in this study were: glioblastoma (n = 11), anaplastic astrocytoma (n = 3), meningioma (n = 7), cerebral metastasis (n = 5) and intracerebral abscess formation (n = 1). Primary brain tumours and cerebral metastases were not distinguishable in terms of |G*| and φ. Glioblastoma presented the largest range of |G*| values and a trend was delineable that glioblastoma were slightly softer than WHO grade III tumours. In terms of φ, meningiomas were clearly distinguishable from all other entities.

CONCLUSIONS

In this pilot study, while analysing the viscoelastic constants of various intracranial tumour entities with an improved spatial resolution, it was possible to characterize intracranial tumours by their mechanical properties. We were able to clearly delineate meningiomas from intraaxial tumours, while for the latter group an overlap remains in viscoelastic terms.

It Is Time to Reevaluate the Management of Patients With Brain Metastases

There are many elements to the science that drives the clinical care of patients with brain metastases. Although part of an understanding that continues to evolve, a number of key historical misconceptions remain that commonly drive physicians' and researchers' attitudes and approaches. By understanding how these relate to current practice, we can better comprehend our available science to provide both better research and care. These past misconceptions include: Misconception 1: Once a primary cancer spreads to the brain, the histology of that primary tumor does not have much impact on response to chemotherapy, sensitivity to radiation, risk of further brain relapse, development of additional metastatic lesions, or survival. All tumor primary histologies are the same once they spread to the brain. They are the same in terms of the number of tumors, radiosensitivity, chemoresponsiveness, risk of further brain relapse, and survival. Misconception 2: The number of brain metastases matters. This number matters in terms of subsequent brain relapse, survival, and cognitive dysfunction; the precise number of metastases can also be used as a limit in determining which patients might be eligible for a particular treatment option. Misconception 3: Cancer in the brain is always a diffuse problem due to the presence of micrometastases. Misconception 4: Whole-brain radiation therapy invariably causes disabling cognitive dysfunction if a patient lives long enough. Misconception 5: Most brain metastases are symptomatic. Thus, it is not worth screening patients for brain metastases, especially because the impact on survival is minimal. The conduct and findings of past clinical research have led to conceptions that affect clinical care yet appear limiting.

Challenges relating to solid tumour brain metastases in clinical trials, part 2: neurocognitive, neurological, and quality-of-life outcomes. A report from the RANO group

Neurocognitive function, neurological symptoms, functional independence, and health-related quality of life are major concerns for patients with brain metastases. The inclusion of these endpoints in trials of brain metastases and the methods by which these measures are assessed vary substantially. If functional independence or health-related quality of life are planned as key study outcomes, then the reliability and validity of these endpoints can be crucial because methodological issues might affect the interpretation and acceptance of findings. The Response Assessment in Neuro-Oncology (RANO) working group is an independent, international, and collaborative effort to improve the design of clinical trials in patients with brain tumours. In this report, the second in a two-part series, we review clinical trials of brain metastases in relation to measures of clinical benefit and provide a framework for the design and conduct of future trials.