Distribution of the novel antifolate pemetrexed to the brain

Long-term survival after salvage pemetrexed for refractory primary T-cell lymphoma of the CNS

Primary T-cell CNS lymphoma is a rare and aggressive malignancy. High-dose methotrexate (MTX) based chemotherapy regimens are used as standard first-line treatment, followed by consolidative strategies to improve the duration of response. Although MTX-based therapy has been shown to be efficacious, treatment options for MTX-refractory disease are not well-defined. Here, we report a case of a 38-year-old man with refractory primary T-cell CNS lymphoma who demonstrated a complete response to pemetrexed treatment. He subsequently received conditioning chemotherapy consisting of thiotepa, busulfan and cyclophosphamide followed by autologous stem cell transplantation. The patient continues to remain recurrence-free to date at 9 years post-treatment.

Efficacy and Safety of Intrathecal Pemetrexed Combined With Dexamethasone for Treating Tyrosine Kinase Inhibitor-Failed Leptomeningeal Metastases From EGFR-Mutant NSCLC-a Prospective, Open-Label, Single-Arm Phase 1/2 Clinical Trial (Unique Identifier: ChiCTR1800016615)

INTRODUCTION

We aimed to evaluate the efficacy and safety of intrathecal pemetrexed (IP) for treating EGFR-mutant leptomeningeal metastases (LMs) from EGFR-mutant NSCLC.

METHODS

Patients with EGFR-mutant NSCLC with LM who had failed tyrosine kinase inhibitors were recruited. The dose of IP was escalated from 15 mg to 80 mg using an accelerated titration design in a phase 1 study. The recommended dose (RD) determined in phase 1 was used in the phase 2 study. The primary end point was treatment efficacy measured as the clinical response rate. Overall survival and adverse events (AEs) were evaluated as secondary end points.

RESULTS

The RD observed in the phase 1 study was 50 mg pemetrexed. A total of 30 cases of LM-NSCLC were enrolled in the phase 2 study, including 14 males and 16 females. Four patients did not survive for 4 weeks and could not be evaluated for efficacy. The clinical response rate was 84.6% (22 of 26). The median overall survival of all patients was 9.0 months (n = 30, 95% confidence interval: 6.6-11.4 mo). Most AEs were mild, and the most frequent AE of any grade was myelosuppression (n = 9, 30%), which returned to normal after symptomatic treatment.

CONCLUSIONS

This study revealed that 50 mg pemetrexed is the RD which results in few AEs and a good response rate. IP is an effective treatment for patients with EGFR-mutant NSCLC-LM who had failed on tyrosine kinase inhibitor.

Challenges and Novel Opportunities of Radiation Therapy for Brain Metastases in Non-Small Cell Lung Cancer

Simple Summary

Lung cancer is the most common primary malignancy that tends to metastasize to the brain. Owing to improved survival of lung cancer patients, the prevalence of brain metastases is a matter of growing concern. Brain radiotherapy remains the mainstay in the management of metastatic CNS disease. However, new targeted therapies such as the tyrosine kinase or immune checkpoint inhibitors have demonstrated intracranial activity and promising tumor response rates. Here, we review the current and emerging therapeutical strategies for brain metastases from non-small cell lung cancer, both brain-directed and systemic, as well as the uncertainties that may arise from their combination.

Abstract

Approximately 20% patients with non-small cell lung cancer (NSCLC) present with CNS spread at the time of diagnosis and 25–50% are found to have brain metastases (BMs) during the course of the disease. The improvement in the diagnostic tools and screening, as well as the use of new systemic therapies have contributed to a more precise diagnosis and prolonged survival of lung cancer patients with more time for BMs development. In the past, most of the systemic therapies failed intracranially because of the inability to effectively cross the blood brain barrier. Some of the new targeted therapies, especially the group of tyrosine kinase inhibitors (TKIs) have shown durable CNS response. However, the use of ionizing radiation remains vital in the management of metastatic brain disease. Although a decrease in CNS-related deaths has been achieved over the past decade, many challenges arise from the need of multiple and repeated brain radiation treatments, which carry along not insignificant risks and toxicity. The combination of stereotactic radiotherapy and systemic treatments in terms of effectiveness and adverse effects, such as radionecrosis, remains a subject of ongoing investigation. This review discusses the challenges of the use of radiation therapy in NSCLC BMs in view of different systemic treatments such as chemotherapy, TKIs and immunotherapy. It also outlines the future perspectives and strategies for personalized BMs management.

First-line pemetrexed and carboplatin plus anlotinib for epidermal growth factor receptor wild-type and anaplastic lymphoma kinase-negative lung adenocarcinoma with brain metastasis: A case report and review of the literature

RATIONALE

Brain metastasis (BM) is a serious complication in non-small cell lung cancer (NSCLC) patients. Pemetrexed is one of the preferred agents in nonsquamous NSCLC with BM; however, the traditional chemotherapy demonstrated limited efficacy partly due to drug resistance and the blood-brain barrier.

PATIENT CONCERNS

A 52-year-old male non-smoker was admitted for irritating cough, chest distress, and back pain.

DIAGNOSES

Epidermal growth factor receptor wild-type, anaplastic lymphoma kinase-negative primary lung adenocarcinoma with an asymptomatic solitary BM (cTxNxM1b, IVA).

INTERVENTIONS

Pemetrexed (500 mg/m of body surface area) and carboplatin (area under the curve of 5) were firstly administered every 3 weeks for 3 cycles, followed by pemetrexed/carboplatin plus anlotinib (12 mg daily; 2 weeks on and 1 week off) for another 3 cycles. Then maintenance anlotinib monotherapy was continued for a year, without unacceptable adverse events.

OUTCOMES

The BM was slightly enlarged after 3 cycles of pemetrexed/carboplatin; however, a complete remission was achieved after the combination therapy. His intracranial progression-free survival was more than 2 years.

LESSONS

Pemetrexed/carboplatin plus anlotinib could be considered for the treatment of epidermal growth factor receptor wild-type, anaplastic lymphoma kinase-negative lung adenocarcinoma with BM. Further well-designed trials are warranted to verify this occasional finding.

Pemetrexed in Recurrent or Progressive Central Nervous System Lymphoma: A Phase I Multicenter Clinical Trial

LESSONS LEARNED

The findings from this study using monotherapy with pemetrexed in a pretreated patient population are, overall, encouraging. Unlike high-dose methotrexate, which requires several days of inpatient hospitalization, pemetrexed is relatively easy to administer in the outpatient setting and remains a viable treatment option in this patient population. The maximum tolerated dose of pemetrexed administered (900 mg/m² every 2 weeks) was generally well tolerated and showed activity in patients with relapsed or refractory CNSL.

BACKGROUND

There is currently no standard salvage treatment for patients with relapsed/refractory central nervous system (CNS) lymphoma (CNSL). We report the results of a phase I study of pemetrexed, an antifolate drug with broader activity than methotrexate (MTX). We provide the safety, tolerability, and maximum tolerated dose (MTD) of pemetrexed in patients with recurrent CNSL.

METHODS

Through October 2015, 17 patients with relapsed/refractory CNSL received pemetrexed every 2 weeks with the first cohort receiving 600 mg/m² and dose escalation in increments of 300 mg/m² to a maximum of 1,200 mg/m² . Three patients were to enroll at each dose level with expansion to six patients in the event of dose-limiting toxicity. Patients with both primary CNS lymphoma (PCNSL) and secondary CNS lymphoma (SCNSL) could be enrolled.

RESULTS

Seventeen patients were evaluable with a median age of 63.7 years. Main adverse events included fatigue (82.4%), anemia (82.4%), and neutropenia (70.6%). The MTD was established at 900 mg/m² . Dose-limiting toxicities were recorded in one patient in the 600 mg/m² cohort and in two patients in the 1,200 mg/m² cohort. Fourteen patients were evaluable for response assessment; 21.4% achieved a complete response, 35.7% had a partial response, 14.3% had stable disease, and 28.6% had progressive disease. The median progression-free survival was 4.2 months. The median overall survival was 44.5 months. In the original study protocol, the plan was to add an expansion cohort of six patients at MTD level. However, the first phase of the study was characterized by slow recruitment. Therefore, after achieving the primary objective of the study and establishing the MTD, the investigators decided to amend the protocol and to close the study.

CONCLUSION

Pemetrexed administered at 900 mg/m² every 2 weeks exhibits single-agent activity in patients with recurrent CNSL; it is well tolerated, and side effects are manageable.

PD-1/PD-L1 Blockers in NSCLC Brain Metastases: Challenging Paradigms and Clinical Practice

Immune checkpoint inhibitors (ICI) have revolutionized the management of advanced non-small cell lung cancer (NSCLC). However, most pivotal phase III trials systematically excluded patients with active brain metastases, precluding the generalization of the results. Although theoretically restricted from crossing the blood-brain barrier, the novel pharmacokinetic/pharmacodynamic profiles of anti-PD-1/PD-L1 drugs have prompted studies to evaluate their activity in patients with NSCLC with active central nervous system (CNS) involvement. Encouraging results have suggested that ICI could be active in the CNS in selected patients with driver-negative advanced NSCLC with high PD-L1 expression and low CNS disease burden. Single-agent CNS response rates around 30% have been reported. Beyond this particular setting, anti-PD-1/PD-L1 antibodies have been evaluated in patients receiving local therapy for brain metastases (BM), addressing concerns about potential neurologic toxicity risks associated with radiotherapy, more specifically, radionecrosis (RN). Accordingly, a variety of clinical and imaging strategies are being appropriately developed to evaluate tumor response and to rule out pseudoprogression or radionecrosis. Our purpose is to critically summarize the advances regarding the role of systemic anti-PD-1/PD-L1 antibodies for the treatment of NSCLC BM. Data were collected from the PubMed database, reference lists, and abstracts from the latest scientific meetings. Recent reports suggest anti-PD-1/PD-L1 agents are active in a subset of patients with NSCLC with BM showing acceptable toxicity. These advances are expected to change soon the management of these patients but additional research is required to address concerns regarding radionecrosis and the appropriate sequencing of local and systemic therapy combinations.

A Pilot Phase 1 Study of Intrathecal Pemetrexed for Refractory Leptomeningeal Metastases From Non-small-cell Lung Cancer

Objectives: We aim to determine the feasibility, safety, maximally tolerated dose (MTD), recommended dose and potential anti-tumor activity of intrathecal pemetrexed (IP).

Materials and Methods: Lung adenocarcinoma patients with recurrent or progressive leptomeningeal metastases (LM) after intrathecal chemotherapy were recruited. IP dose was escalated from 10 mg. A minimum of three patients and a maximum of six were enrolled in each cohort. Schedule protocol was IP twice per week for 2 weeks in induction therapy, followed by once per week for 4 weeks in consolidation therapy. Serial samples of plasma and cerebrospinal fluid (CSF) were obtained for pharmacokinetic studies.

Results: Thirteen patients were enrolled between March 2017 and July 2018. EGFR driver oncogene was identified in most of the patients. Severe adverse events (AEs) were encountered in 31% (4/13) of the cases, including myelosuppression, radiculitis, and elevation of hepatic aminotransferases (EHA). Study protocol was revised due to lethal myelosuppression. Following protocol revision, vitamin B12 and folic acid supplementation was given at the beginning of treatment, and myelosuppression was well-controlled. Dose-limiting toxicities (DLT) were myelosuppression, radiculitis, and EHA. Two patients (2/2) developed dose-limiting myelosuppression at 15 mg level. One patient (1/6) experienced dose-limiting radiculitis and EHA at 10 mg level. MTD was 10 mg. Response rate was 31% (4/13) and disease control rate was 54% (7/13). The drug concentration showed a decreasing trend in serial CSF samples following each IP. After IP, the peak plasma concentration was reached at 4 h in two cases, 6 h in two cases, 9 h in one case, and 12 h in one case, respectively.

Conclusion: Pemetrexed was appropriate for intrathecal administration. IP at 10 mg dose in combination with vitamin supplementation on the schedule of 1–2 times per week showed controllable toxicity and good efficacy. This regimen paves the way for subsequent clinical trial.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT03101579.

Impact of pemetrexed on intracranial disease control and radiation necrosis in patients with brain metastases from non-small cell lung cancer receiving stereotactic radiation

BACKGROUND

Pemetrexed is a folate antimetabolite used in the management of advanced adenocarcinoma of the lung. We sought to assess the impact of pemetrexed on intracranial disease control and radiation-related toxicity among patients with adenocarcinoma of the lung who received stereotactic radiation for brain metastases.

MATERIALS/METHODS

We identified 149 patients with adenocarcinoma of the lung and newly diagnosed brain metastases without a targetable mutation receiving stereotactic radiation. Kaplan-Meier plots and Cox regression were employed to assess whether use of pemetrexed was associated with intracranial disease control and radiation necrosis.

RESULTS

Among the entire cohort, 105 patients received pemetrexed while 44 did not. Among patients who were chemotherapy-naïve, use of pemetrexed (n = 43) versus alternative regimens after stereotactic radiation (n = 24) was associated with a reduced likelihood of developing new brain metastases (HR 0.42, 95% CI 0.22-0.79, p = 0.006) and a reduced need for salvage brain-directed radiation therapy (HR 0.36, 95% CI 0.18-0.73, p = 0.005). Pemetrexed use was associated with increased radiographic necrosis. (HR 2.70, 95% CI 1.09-6.70, p = 0.03).

CONCLUSIONS

Patients receiving pemetrexed after brain-directed stereotactic radiation appear to benefit from improved intracranial disease control at the possible expense of radiation-related radiographic necrosis. Whether symptomatic radiation injury occurs more frequently in patients receiving pemetrexed requires further study.

A pooled analysis of advanced nonsquamous non-small cell lung cancer patients with stable treated brain metastases in two phase II trials receiving bevacizumab and pemetrexed as second-line therapy

Background

Brain metastases are a common complication of advanced non-small cell lung cancer (NSCLC). Patients with brain metastases were excluded from the registration trials of bevacizumab that showed a survival benefit with the use of angiogenesis inhibition.

Methods

In this study, we pooled data from two separate trials designed to evaluate the risk of central nervous system (CNS) hemorrhage in patients with stable treated brain metastases to look specifically at both the safety and efficacy of bevacizumab and pemetrexed when used as second-line treatment in NSCLC patients with stable treated brain metastases.

Results

We report acceptable safety and promising efficacy from our analysis.

Conclusions

Our study adds further evidence of safety of administering pemetrexed and bevacizumab to patients with stable brain metastases. There is increasing roles for systemic therapies to treat stable brain metastases for patients with advanced NSCLC.

Development and characterization of cationic solid lipid nanoparticles for co-delivery of pemetrexed and miR-21 antisense oligonucleotide to glioblastoma cells

The practical use of solid lipid nanoparticles (SLNs) in research has been highlighted in the literature, but few reports have combined SLNs with miRNA-based therapy and chemotherapy. We aimed to prepare cationic SLNs (cSLNs) to load anti-miR-21 oligonucleotide and pemetrexed for glioblastoma therapy in vitro. cSLNs were employed to encapsulate both pemetrexed and anti-miR-21 by a high-pressure homogenization method, and then the properties of cSLNs were characterized. We studied cellular uptake and cytotoxicity properties of cSLNs in U87MG cells. cSLNs were 124.9 ± 1.6 nm in size and 27.3 ± 1.6 mV in zeta potential with spherical morphology in the TEM image. cSLNs uptake by U87MG cells was increased significantly higher and more effective than free pemetrexed. These findings suggest that cSLNs represent a potential new approach for carrying both pemetrexed and anti-miR-21 for glioblastoma therapy.

Blood-Brain Barrier and Breast Cancer Resistance Protein: A Limit to the Therapy of CNS Tumors and Neurodegenerative Diseases

The treatment of brain tumors and neurodegenerative diseases, represents an ongoing challenge. In Central Nervous System (CNS) the achievement of therapeutic concentration of chemical agents is complicated by the presence of distinct set of efflux proteins, such as ATP-Binding Cassette (ABC) transporters localized on the Blood-Brain Barrier (BBB). The activity of ABC transporters seems to be a common mechanism that underlies the poor response of CNS diseases to therapies.

The molecular characterization of Breast Cancer Resistance Protein (BCRP/ABCG2), as an ABC transporter conferring multidrug resistance (MDR), has stimulated many studies to investigate its activity on the BBB, its involvement in physiology and CNS diseases and its role in limiting the delivery of drugs in CNS.

In this review, we highlight the activity and localization of BCRP on the BBB and the action that this efflux pump has on many conventional drugs or latest generation molecules used for the treatment of CNS tumors and other neurodegenerative diseases.

Greater efficacy of chemotherapy plus bevacizumab compared to chemo- and targeted therapy alone on non-small cell lung cancer patients with brain metastasis

Control of non-small-cell lung cancer (NSCLC) with brain metastasis is clinically challenging. This study retrospectively evaluated the efficacy of different adjuvant therapies for 776 cases of advanced NSCLCs with brain metastasis who treated with chemotherapy, chemotherapy plus bevacizumab, tyrosine kinase inhibitor (TKI) alone, or supportive care. The median progression-free survival (mPFS) and median overall survival (mOS) of patients treated with chemotherapy plus bevacizumab were 8.5 and 10.5 months, respectively, which were better than those of patients treated with other three therapies(P < 0.01). For patients with EGFR-mutated NSCLC, the efficacy of TKI treatment was not statistically better than that of chemotherapy plus bevacizumab but was significantly better than that of other therapies. Moreover, for patients with EGFR wild-type NSCLC, the mPFS and mOS after chemotherapy plus bevacizumab were greater than those with other two therapies (P < 0.01). The local response rate (RR)and disease control rate (DCR)with regimen including pemetrexed were greater than those with regimen including paclitaxel (P < 0.05). Chemotherapy plus bevacizumab was more effective for NSCLC patients with brain metastasis. Further studies will investigate the benefit of TKI alone for patients with EGFR-mutated. For patients with EGFR wild-type, chemotherapy plus bevacizumab did improve PFS and OS. Furthermore, regimens including pemetrexed led to a greater RR.

Co-delivery of pemetrexed and miR-21 antisense oligonucleotide by lipid-polymer hybrid nanoparticles and effects on glioblastoma cells

Combination therapy using anticancer drugs and nucleic acid is a more promising strategy to overcome multidrug resistance in cancer and to enhance apoptosis. In this study, lipid-polymer hybrid nanoparticles (LPNs), which contain both pemetrexed and miR-21 antisense oligonucleotide (anti-miR-21), have been developed for treatment of glioblastoma, the most aggressive type of brain tumor. Prepared LPNs have been well characterized by particle size distribution and zeta potential measurements, determination of encapsulation efficiency, and in vitro release experiments. Morphology of LPNs was determined by transmission electron microscopy. LPNs had a hydrodynamic size below 100 nm and exhibited sustained release of pemetrexed up to 10 h. Encapsulation of pemetrexed in LPNs increased cellular uptake from 6% to 78%. Results of confocal microscopy analysis have shown that co-delivery of anti-miR-21 significantly improved accumulation of LPNs in the nucleus of U87MG cells. Nevertheless, more effective cytotoxicity results could not be obtained due to low concentration of anti-miR-21, loaded in LPNs. We expect that the effective drug delivery systems can be obtained with higher concentration of anti-miR-21 for the treatment of glioblastoma.

Pemetrexed induces G1 phase arrest and apoptosis through inhibiting Akt activation in human non small lung cancer cell line A549

Pemetrexed is an antifolate agent which has been used for treating malignant pleural mesothelioma and non small lung cancer in the clinic as a chemotherapeutic agent. In this study, pemetrexed inhibited cell growth and induced G1 phase arrest in the A549 cell line. To explore the molecular mechanisms of pemetrexed involved in cell growth, we used a two-dimensional polyacrylamide gel electrophoresis (2-DE) proteomics approach to analyze proteins changed in A549 cells treated with pemetrexed. As a result, twenty differentially expressed proteins were identified by ESI-Q-TOF MS/MS analysis in A549 cells incubated with pemetrexed compared with non-treated A549 cells. Three key proteins (GAPDH, HSPB1 and EIF4E) changed in pemetrexed treated A549 cells were validated by Western blotting. Accumulation of GAPDH and decrease of HSPB1 and EIF4E which induce apoptosis through inhibiting phosphorylation of Akt were noted. Expression of p-Akt in A549 cells treated with pemetrexed was reduced. Thus, pemetrexed induced apoptosis in A549 cells through inhibiting the Akt pathway.

Activity of pemetrexed-based regimen as first-line chemotherapy for advanced non-small cell lung cancer with asymptomatic inoperable brain metastasis: a retrospective study

This retrospective study was conducted to assess the efficacy of combination of pemetrexed and cisplatin/carboplatin as first-line treatment in inoperable and asymptomatic brain metastasis (BM) from non-small cell lung cancer (NSCLC). A total of 30 patients with adenocarcinoma were included. Nine patients had solitary, and 21 patients had multiple BM. At evaluation after two cycles, the complete response (CR) rate, partial response (PR) rate, and stable disease (SD) for brain lesions was 0, 33.3, and 46.7%, respectively. The overall CR, PR, and SD were 0, 23.3, and 46.7%, respectively. The median time to tumour progression of BM (TTP-BM) was 6.0 months (95% CI 4.068-7.932). The median progression-free survival (PFS) and overall survival (OS) were 5.0 months (95% CI 4.197-5.803) and 11.0 months (95% CI 7.398-14.602), respectively. Pemetrexed has comparable activity on brain lesions as on extracranial tumours in advanced lung adenocarcinoma patients with inoperable and asymptomatic BM.

An NMR metabolomics approach for the diagnosis of leptomeningeal carcinomatosis in lung adenocarcinoma cancer patients

Leptomeningeal carcinomatosis (LC) is a metastatic cancer invading the central nervous system (CNS). We previously reported a metabolomic diagnostic approach as tested on an animal model and compared with current modalities. Here, we provide a proof of concept by applying it to human LC originating from lung cancer, the most common cause of CNS metastasis. Cerebrospinal fluid from LC (n = 26) and normal groups (n = 41) were obtained, and the diagnosis was established with clinical signs, cytology, MRI and biochemical tests. The cytology on the CSF, the current gold standard, exhibited 69% sensitivity (~100% specificity) from the first round of CSF tapping. In comparison, the nuclear magnetic resonance spectra on the CSF showed a clear difference in the metabolic profile between the LC and normal groups. Multivariate analysis and cross-validation yielded the diagnostic sensitivity of 92%, the specificity of 96% and the area under the curve (AUC) of 0.991. Further spectral and statistical analysis identified myo-inositol (p < 5 × 10(-14)), creatine (p < 7 × 10(-8)), lactate (p < 9 × 10(-4)), alanine (p < 7.9 × 10(-3)) and citrate (p < 3 × 10(-4)) as the most contributory metabolites, whose combination exhibited an receiver-operating characteristic diagnostic AUC of 0.996. In addition, the metabolic profile could be correlated with the grading of radiological leptomeningeal enhancement (R(2) = 0.3881 and p = 6.66 × 10(-4)), suggesting its potential utility in grading LC. Overall, we propose that the metabolomic approach might augment current diagnostic modalities for LC, the accurate diagnosis of which remains a challenge.

First assessment of whole-brain radiation therapy combined with pemetrexed-based chemotherapy in non-small-cell lung carcinoma: data on safety and efficacy

The folate antimetabolite pemetrexed was approved for the treatment of patients with metastatic nonsquamous non-small-cell lung carcinoma. Its activity on brain metastases makes pemetrexed attractive in combination with whole-brain radiation therapy (WBRT), but it could also potentially increase toxicity. We examined the medical records of 43 consecutive patients with brain metastases from non-small-cell lung carcinoma. Patients received pemetrexed-based chemotherapy at a dose of 500 mg/m. The median total number of pemetrexed-based chemotherapy cycles was 4 (range: 1-28). During the course of chemotherapy, patients received WBRT delivering 30 Gy in 10 fractions (n=34) or 20 Gy in five fractions (n=9). The median follow-up time was 30.5 weeks (range: 1-79 weeks). Intracranial progression was a cause of death in nine patients (20.9%). Clinical benefit of WBRT was reported in 30 patients (69.8%). The best radiological response was a complete response in eight patients (18.6%), a partial response in 16 patients (37.2%), stable disease in 11 patients (25.6%), and progression in four patients (9.3%). A stable intracranial disease until the last follow-up was observed in 26 patients (60.5%). The median estimated overall survival was 31 weeks (95% CI: 24-37 weeks). Most WBRT-related toxicities were low and 21 patients (48.9%) had no reported acute neurological toxicity. One patient developed unexplained encephalopathy 5 weeks after WBRT completion in the context of progressive diffuse brain metastases. The combination of pemetrexed with WBRT led to considerable clinical improvement and tumor responses in most patients. Overall neurological toxicity was rather low. A clinical trial is essential for better analysis of the potential synergistic effects of a drug with radiation and evaluation of neurological toxicity.

Chemotherapy and EGFR tyrosine kinase inhibitors for treatment of brain metastases from non-small-cell lung cancer: survival analysis in 210 patients

BACKGROUND

Chemotherapy and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors are controversial in the treatment of patients with brain metastases from non-small-cell lung cancer (NSCLC).

METHODS

We retrospectively studied the effects of solely localized treatment or localized treatment in combination with chemotherapy and/or EGFR tyrosine kinase inhibitors on outcomes in 210 NSCLC patients with brain metastases. The effects of treatment modality, Karnofsky performance status, age, primary tumor histology, number of brain metastases, and other factors on survival time were analyzed, and the robustness of two prognostic indices, ie, recursive partitioning analysis and graded prognostic assessment, was evaluated.

RESULTS

The median survival time in patients with systemic medication and localized treatments was higher than in those with localized treatments alone (11 versus 3 months, P=0.000). Within the systemic medication group, median survival time was significantly longer for EGFR tyrosine kinase inhibitors than for other types of chemotherapy (12 versus 9 months, P=0.002). In the EGFR tyrosine kinase inhibitor group, median survival time for patients with EGFR gene mutation was 20 months versus 8 months for those with the wild-type EGFR gene. The median survival time with pemetrexed was significantly higher than with other chemotherapies (13 versus 7 months, P=0.006). In multivariate analysis, the prognosis was significantly correlated with treatment modality (P=0.000), Karnofsky performance status (P=0.000), number of brain metastases (P=0.001), and histologic tumor type (P=0.007). In the graded prognostic assessment model, survival curves for the subgroups showed clear separations.

CONCLUSION

NSCLC patients with brain metastasis benefited from pemetrexed and/or tyrosine kinase inhibitors along with localized treatments, and the graded prognostic assessment index is a robust model for prognostic evaluation.

Brain efflux index to investigate the influence of active efflux on brain distribution of pemetrexed and methotrexate

Antifolates, in particular methotrexate (MTX), have been widely used in the treatment of primary and secondary tumors of the central nervous system (CNS). Pemetrexed (PMX) is a novel antifolate that also exhibits potent antitumor activity against CNS malignancies. Studies have shown that brain distribution of both antifolates is significantly restricted, possible due to active efflux transport at the blood-brain barrier (BBB). This study characterizes the brain-to-blood transport of PMX and MTX and examines the role of several efflux transporters in brain distribution of the antifolates by use of the intracerebral microinjection technique (brain efflux index). The results from this study show that both PMX and MTX undergo saturable efflux transport across the BBB, with elimination half-lives of approximately 39 minutes and 29 minutes, respectively. Of the various efflux transporters this study investigated, multidrug resistance-associated protein 2 (Mrp2) does not play an important role in the brain distribution of the two antifolate drugs. Interestingly, breast-cancer resistance protein (Bcrp) makes a significant contribution to the brain elimination of MTX but not PMX. In addition, the brain-to-blood transport of both antifolates was inhibited by probenecid and benzylpenicillin, suggesting the involvement of organic anion transporters in the efflux of these compounds from the brain, with organic anion transporter 3 (Oat3) being a possibility. Our results suggest that one of the underlying mechanisms behind the limited brain distribution of PMX and MTX is active efflux transport processes at the BBB, including a benzylpenicillin-sensitive transport system and/or the active transporter Bcrp.

Efficacy of intraperitoneal versus intravenous pemetrexed administration in management of malignant ascites in mice bearing ascitic hepatoma-22

AIM: To compare the effectiveness of intraperitonea and intravenous administration of pemetrexed (PEM) in the management of malignant ascites in mice bearing hepatoma-22 (H22).

METHODS: A mouse model of ascites was established by intraperitoneal injection of 0.2 mL of H22 cell suspension (at a density of 1 × 10⁷/mL cells). The mice were randomly divided into three groups at random on day 5 after induction of ascites (n = 18 per group): normal control group (normal saline), intraperitoneal pemetrexed group (PEM 300 mg/kg), and intravenous pemetrexed group (PEM 300 mg/kg). Pemetrexed was injected intraperitoneally or intravenously on days 5 and 8. The body weight, abdomen circumference and behavior of the mice were measured daily. Eight mice of each group were sacrificed on day 11 to measure the volume of ascites. The survival time of rest mice were recorded.

RESULTS: The mean volumes of ascites in the normal control group, intraperitoneal pemetrexed group and intravenous pemetrexed group were 15.74 mL ± 1.71 mL, 13.31 mL ± 2.45 mL and 8.58 mL ± 1.89 mL, respectively. In comparison to the normal control group, the two pemetrexed treatment group had significantly less production of ascites in (both P < 0.05). The mean volume of ascites in the intraperitoneal pemetrexed group was significantly lower than that in the intravenous administration group (P < 0.01). The mean survival times of mice in the intraperitoneal pemetrexed group, intravenous pemetrexed group, and normal control group were 15.10 d ± 0.46 d, 17.90 d ±0.71 d, and 14.20 d ± 0.44 d, respectively. The survival time was prolonged by 6.34% and 26.06% in the intraperitoneal pemetrexed group and intravenous pemetrexed group compared to the normal control group. There was no significant difference in the survival time between the intraperitoneal pemetrexed group and normal control group (P > 0.05), but the mean survival time was significantly longer in the intravenous pemetrexed group than in the normal control group and intraperitoneal pemetrexed group (both P < 0.01).

CONCLUSION: Intraperitoneal administration of pemetrexed is not superior to traditional intravenous administration in the management of malignant ascites in mice bearing ascitic hepatoma-22.

Efficacy assessment of pemetrexed treatment of an NSCLC case with brain metastasis

Non-small cell lung cancers (NSCLCs) are among the most common malignancies. Although pemetrexed is often used clinically to cure cancers, its efficacy in NSCLC patients with progressive brain metastases remains unclear. Here, we report a successful NSCLC (adenocarcinoma) case treated with pemetrexed. The detected tumors were treated with 900 mg of pemetrexed disodium (500 mg/m(2)) was administered to the patient on day 1, and 40 mg of cisplatin (25mg/m(2)) was administered on days 1-3, at the interval of 3 weeks. After two cycles of chemotherapy, the brain metastases were reduced. The lesion in the lung was reduced as determined by chest CT-scan. Our results suggest that pemetrexed is an effective therapy for patients with NSCLC and progressive brain metastases.

Oncogene status predicts patterns of metastatic spread in treatment-naive nonsmall cell lung cancer

BACKGROUND

The discovery of distinct subsets of nonsmall cell lung cancer (NSCLC) characterized by activation of driver oncogenes has greatly affected personalized therapy. It is hypothesized that the dominant oncogene in NSCLC would be associated with distinct patterns of metastatic spread in NSCLC at the time of diagnosis.

METHODS

A total of 209 consecutive patients with stage IV nonsquamous NSCLC with an EGFR (epidermal growth factor receptor) mutation (N = 39), KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) mutation (N = 49), ALK (anaplastic lymphoma receptor tyrosine kinase) gene rearrangement (N = 41), or wild-type for all 3 (triple negative, N = 80) were included. The percentage of patients with metastatic disease at a given site was compared between each molecular cohort (EGFR, KRAS, or ALK) and the triple negative cohort.

RESULTS

ALK gene rearrangement was significantly associated with pericardial disease (odds ratio [OR] = 4.61; 95% confidence interval [CI] = 1.30, 16.37; P = .02) and pleural disease (OR = 4.80; 95% CI = 2.10, 10.97; P < .001). Patients with ALK gene rearrangements (OR = 5.50; 95% CI = 1.76, 17.18; P = .003) and patients with EGFR mutations (OR = 5.17; 95% CI = 1.63, 16.43; P = .006) were predisposed to liver metastasis compared to the triple negative cohort. No molecular cohort had a predisposition to pulmonary nodules, or adrenal, bone, or brain metastasis compared to the triple negative cohort. The mean number of metastatic disease sites in patients within the ALK rearranged cohort was significantly greater than that of the triple negative cohort (mean = 3.6 sites vs 2.5 sites, P < .0001).

CONCLUSIONS

The results support the hypothesis that the dominant molecular oncogenes in NSCLC are associated with different biological behaviors manifesting as distinct patterns of metastatic spread at the time of diagnosis.

Safety and pharmacokinetics of intrathecal administration of pemetrexed in rats

PURPOSE

Leptomeningeal carcinomatosis is a devastating complication of malignant disease. In this study, we evaluated the safety and pharmacokinetics of intrathecally administered pemetrexed in rats.

METHODS

Three levels of pemetrexed (0.3, 1, and 3 mg/kg) were administered to 15 rats per level (45 rats in total) twice a week for 2 weeks through specifically designed indwelling subarachnoid catheters. Presence of clinical and pathological neurotoxicity was evaluated. To evaluate the pharmacokinetics of pemetrexed, independent cohorts of 30 rats were treated with 1 mg/kg of pemetrexed and its concentration in cerebrospinal fluid (CSF) and blood was measured using UPLC/MS/MS.

RESULTS

There were no cases of clinical or pathologic neurotoxicity after intrathecal administrations of pemetrexed at levels of 0.3 and 1 mg/kg; however, 5 of 15 (33%) rats died after administration of 3 mg/kg pemetrexed. The distribution/elimination of pemetrexed in CSF was best described by a two-compartment model, with initial and terminal half-lives of 0.43 and 1.43 h, respectively. The predicted maximal concentration in CSF was 588 μM, and high levels of pemetrexed appeared to be maintained for a long time. Area under the curve and volume of distribution at steady state were 560 μM h and 1.14 ml, respectively.

CONCLUSIONS

The no observed adverse effect level of intrathecal administration of pemetrexed was 1 mg/kg in rats. At this level, therapeutically high and durable pemetrexed concentrations could be achieved. Based on these results, further research on intrathecal pemetrexed in humans or non-human primates should be considered.

Concomitant chemoradiotherapy using pemetrexed and carboplatin for unresectable stage III non-small cell lung cancer (NSCLC): preliminary results of a phase II study

BACKGROUND

Concomitant chemoradiotherapy is the standard treatment of unresectable stage III non-small cell lung cancer (NSCLC). However, the optimal chemotherapy regimen is still controversial. We have conducted a phase II clinical trial in a Chinese population to evaluate concomitant treatment using pemetrexed/carboplatin chemotherapy and thoracic radiotherapy followed by pemetrexed/carboplatin consolidation chemotherapy in these patients. The purpose of this study is to evaluate the feasibility and activity, and also assess its impact on progression-free survival (PFS).

PATIENTS AND METHODS

A total of 21 patients were enrolled between January 2008 and October 2009. Patients received concomitant pemetrexed 500 mg/m(2), carboplatin area under the curve (AUC) 5 chemotherapy on day 1 repeated every 3 weeks for 2 cycles and thoracic radiotherapy, followed by pemetrexed/carboplatin for 3 cycles as consolidation therapy. Objective response rate according to the RECIST criteria was recorded and toxicity was evaluated using the NCI Common Toxicity Criteria. The Kaplan-Meier method was used to evaluate patient survival. Univariate analysis of patient characteristics and tumor responses was conducted using the Chi-square and Fisher's exact test.

RESULTS

Five (23.8%) and 13 patients (61.9%) had a complete or partial response, respectively, while 2 patient's disease remained stable and 1 patient had progression of the disease. The overall response rate (85.7%, 95% confidence interval (CI): 61-97%) exceeded the goal per study design. The median PFS was 12.0 months (95% CI: 10.6-13.4 months). The statistical analysis of predictive factors of efficacy revealed that the response rate and PFS seemed to a trend favoring adenocarcinoma histology. Main toxicity (grade 3 or greater, %): neutropenia 6 (28.5%); thrombocytopenia 4 (19%); anaemia 5 (23.8%); nausea/vomiting 1 (4.8%); anorexia 1 (4.8%), dysphagia 2 (9.5%), radiation pneumonitis 1 (4.8%) and fatigue 2 (9.5%).

CONCLUSION

This data suggests that concomitant treatment with pemetrexed/carboplatin at full systemic doses and thoracic radiotherapy was well tolerated, with promising activity in a Chinese population with unresectable stage III NSCLC. Better outcomes were observed in patients with adenocarcinoma in this study. Although the data presented herewith appears promising, this study is relatively small, and more data from randomized trials are needed to further validate this regimen.

Activity of Pemetrexed on brain metastases from Non-Small Cell Lung Cancer

Brain metastases from Non-Small Cell Lung Cancer are usually associated with poor prognosis and up to now chemotherapy has shown a modest activity upon cerebral localizations. We investigated the role of Pemetrexed, a new, well tolerated multi-target antifolate, on brain metastases.

PATIENTS AND METHODS

We collected 39 patients with evidence of cerebral nervous system (CNS) localizations from Non-Small Cell Lung Cancer (NSCLC) before starting treatment with Pemetrexed as second-line or further-line therapy.

RESULTS

We confirmed the good tolerability of Pemetrexed even in that setting of patients and we reported a progressive disease (PD) in 12 patients (30.8%), a stable disease (SD) and partial response (PR) in 12 (30.8%) and 15 (38.4%) patients respectively, with an overall clinical benefit obtained in 69% of patients. The cerebral response to Pemetrexed was interesting with a cerebral radiological benefit obtained in 32 patients (82%), while 7 patients only showed brain progressive disease. Overall median survival was 10 months. All irradiation-naïve patients and those with clear radiological evidence of cerebral progression after brain radiotherapy and before Pemetrexed, overall 22 patients, were included in one group, in order to avoid overlapping effects between brain radiotherapy and Pemetrexed over CNS localizations. Within that setting, we demonstrated an overall clinical benefit (SD+PR) and cerebral benefit in 63% and 68%, of patients respectively. Distribution of patients by overall response to Pemetrexed and CNS response was highly suggestive of activity of Pemetrexed on brain metastases.

CONCLUSION

We demonstrated the good tolerability of Pemetrexed even in patients with advanced NSCLC and brain metastases, and we found a very good overall response rate with evidence of activity on brain localizations.

Chemotherapy and targeted molecular therapies for brain metastases

As therapy for systemic cancers improves, an increasing number of patients are developing brain metastases. Although conventional therapy with surgery, radiation therapy and radiosurgery has improved the outcome of a significant number of patients, many develop multiple lesions that are not amenable to standard treatments. In this review, the current role of chemotherapy and targeted molecular agents for brain metastases is summarized and future directions are discussed.