Cerebrospinal fluid and plasma methotrexate levels following high-dose regimen given as a 3-hour intravenous infusion in children with nonHodgkin's lymphoma

Modelling the Human Blood-Brain Barrier in Huntington Disease

While blood–brain barrier (BBB) dysfunction has been described in neurological disorders, including Huntington’s disease (HD), it is not known if endothelial cells themselves are functionally compromised when promoting BBB dysfunction. Furthermore, the underlying mechanisms of BBB dysfunction remain elusive given the limitations with mouse models and post mortem tissue to identify primary deficits. We established models of BBB and undertook a transcriptome and functional analysis of human induced pluripotent stem cell (iPSC)-derived brain-like microvascular endothelial cells (iBMEC) from HD patients or unaffected controls. We demonstrated that HD-iBMECs have abnormalities in barrier properties, as well as in specific BBB functions such as receptor-mediated transcytosis.

Influence of MTHFR C677T Polymorphism on High-Dose Methotrexate-Related Toxicity in Patients With Primary Central Nervous System Diffuse Large B-Cell Lymphoma

BACKGROUND

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a relatively rare and aggressive neoplasm. High-dose methotrexate (HD-MTX) is an effective regimen for the treatment of PCNS-DLBCL, but MTX-related toxicity remains a problem. The aim of this analysis study was to investigate the influence of the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism on HD-MTX-related toxicity in patients with PCNS-DLBCL.

MATERIAL/METHODS

A prospective, observational study was conducted to analyze 148 MTX courses in 32 patients with PCNS-DLBCL.

RESULTS

The delayed MTX clearance was observed in 53 cycles (35.8%). The patients carrying the homozygous variant genotype had a higher risk of developing nephrotoxicity than those carrying the wild-type genotype (odds ratio [OR] 13.08; 95% confidence interval [CI], 1.65-103.86; P = .002) or heterozygous variant genotype (OR 8.43; 95% CI, 2.31-30.70; P < .001). Significant differences were observed in hepatotoxicity (OR 9.33; 95% CI, 2.54-34.27; P < .001) and hematologic toxicity (OR 3.09; 95% CI, 1.18-8.07; P = .024) in addition to nephrotoxicity between the homozygous variant genotype and the wild-type genotype.

CONCLUSION

The homozygous mutation of C to T at nucleotide 677 increases the risk on HD-MTX-related toxicity. The MTHFR C677T polymorphism can be used to predict HD-MTX-related toxicity for patients with PCNS-DLBCL.

Pharmacokinetic basis for dosing high-dose methotrexate in infants and young children with malignant brain tumours

AIMS

No population pharmacokinetic studies of high-dose methotrexate (HDMTX) have been conducted in infants with brain tumours, which are a vulnerable population. The aim of this study was to evaluate HDMTX disposition in these children to provide a rational basis for MTX dosing.

METHODS

Patients received 4 monthly courses of HDMTX (5 g/m² or 2.5 g/m² for infants aged ≤31 days) as a 24-h infusion. Serial samples were analysed for MTX by an enzyme immunoassay method. Pharmacokinetic parameters were estimated using nonlinear mixed effects population modelling. Demographics, concomitant medications and genetic polymorphisms were considered as pharmacokinetic covariates while MTX exposure and patient age were considered as covariates for Grade 3 and 4 toxicities.

RESULTS

The population pharmacokinetics of HDMTX were estimated in 178 patients (age range 0.02-4.7 years) in 648 courses. The population clearance and volume were 90 mL/min/m² and 14.4 L/m² , respectively. Significant covariates on body surface area adjusted MTX clearance included estimated glomerular filtration rate and co-treatment with dexamethasone or vancomycin. No significant association was observed between MTX toxicity and MTX exposure, patient age, leucovorin dosage or duration. MTX clearance in infants ≤31 days at enrolment was 44% lower than in older infants, but their incidence of toxicity was not higher since they also received a lower MTX dosage.

CONCLUSIONS

By aggressively following institutional clinical guidelines, HDMTX-related toxicities were low, and using covariates from the population pharmacokinetic model enabled the calculation of a rational dosage for this patient population for future clinical trials.

Primary extra-nodal diffuse large B-cell lymphoma: A prognostic analysis of 141 patients

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of lymphoma. Approximately 40% of DBLCL originates from extra-nodal sites, but the diversity of clinical presentations and the genetic and molecular alterations indicate that extra-nodal DLBCLs may be distinct disease entities. The aim of the present study was to highlight the various aspects of primary extra-nodal DLBCL (PE-DLBCL) based on a single center cohort. The data from 141 patients with PE-DLBCL treated at Peking Union Medical College Hospital were retrospectively evaluated. The primary extra-nodal sites involved were the gastrointestinal tract (n=42), central nervous system (CNS; n=38), breast (n=19), adrenal gland (n=15), female genital system (FGS; n=12), thyroid (n=8) and bone (n=7). The median overall survival rate was 28 months (range, 1–116). Multivariate analysis demonstrated that an International Prognostic Index (IPI) ≤2 (P=0.049), complete remission (CR) achieved following first-line therapy (P=0.001) and chemotherapy combined with rituximab (P<0.001) were positive prognostic factors. Patients with DLBCL with primary adrenal gland or female genital system (FGS) involvement exhibited a significantly higher risk of CNS recurrence (P<0.05). Rituximab treatment may have reduced the likelihood of CNS recurrence (P=0.005), whereas prophylaxis with intrathecal injection alone was not sufficient for prevention (P>0.05). In conclusion, IPI >2 and the lack of a CR following first-line therapy were independent prognostic risk factors for PE-DLBCL. Patients with primary adrenal gland or FGS involvement exhibited a higher risk of CNS relapse. Rituximab had a positive impact on the survival of patients with PE-DLBCL, also reducing the likelihood of CNS relapse.

Advances in the treatment of newly diagnosed primary central nervous system lymphomas

Primary central nervous system lymphoma (PCNSL) is a type of highly invasive non-Hodgkin lymphoma. With a growing number of organ transplantation and immunosuppressant therapy, the incidence of PCNSL has been growing rapidly in recent years, which is attributed to the increased incidence of HIV/AIDS, a prominent risk factor for developing PCNSL. The rising rate of PCNSL incidence is the highest among the intracranial tumors. In the past 20 years, dozens of clinical trials related to PCNSL have been registered, but adequate therapeutics are still challenging. Currently, the chemotherapy regimens based on high-dose methotrexate and whole-brain radiotherapy are the two main therapeutic options; however, the toxicity associated with those is the main problem that challenges medical researchers. Novel agents and therapeutic strategies have been developed in recent years. In the current review, we describe advances in the treatment of PCNSL and discuss novel therapeutic approaches currently in development, such as the use of rituximab, disruption of the blood-brain barrier, and state-of-the-art radiotherapy.

Guidelines for diagnosis, prevention and management of central nervous system involvement in diffuse large B-cell lymphoma patients by the Spanish Lymphoma Group (GELTAMO)

Diffuse large B-cell lymphoma patients have a 5% overall risk of central nervous system events (relapse or progression), which account for high morbidity and frequently fatal outcomes,¹ and shortened overall survival of <6 months.² Early diagnosis of central nervous system events is critical for successful treatment and improved prognosis. Identification of patients at risk of central nervous system disease is critical to accurately identify candidates for central nervous system prophylaxis vs.

THERAPY

^3-5 This report by the Spanish Lymphoma Group (GELTAMO) aims to provide useful guidelines and recommendations for the prevention, diagnosis, and treatment of central nervous system diffuse large B-cell lymphoma patients with, or at risk of, leptomeningeal and/or brain parenchyma lymphoma relapse. A panel of lymphoma experts working on behalf of GELTAMO reviewed all data published on these topics available in PubMed up to May 2016. Recommendations were classified according to the Grading of Recommendations Assessment Development and Evaluation (GRADE) approach.⁶ A practical algorithm based on the proposed recommendations was then developed (Figure 1). Initial discussions among experts were held in May 2014, and final consensus was reached in June 2016. The final manuscript was reviewed by all authors and the Scientific Committee of GELTAMO.

PAN-811 Blocks Chemotherapy Drug-Induced In Vitro Neurotoxicity, While Not Affecting Suppression of Cancer Cell Growth

Chemotherapy often results in cognitive impairment, and no neuroprotective drug is now available. This study aimed to understand underlying neurotoxicological mechanisms of anticancer drugs and to evaluate neuroprotective effects of PAN-811. Primary neurons in different concentrations of antioxidants (AOs) were insulted for 3 days with methotrexate (MTX), 5-fluorouracil (5-FU), or cisplatin (CDDP) in the absence or presence of PAN-811·Cl·H₂O. The effect of PAN-811 on the anticancer activity of tested drugs was also examined using mouse and human cancer cells (BNLT3 and H460) to assess any negative interference. Cell membrane integrity, survival, and death and intramitochondrial reactive oxygen species (ROS) were measured. All tested anticancer drugs elicited neurotoxicity only under low levels of AO and elicited a ROS increase. These results suggested that ROS mediates neurotoxicity of tested anticancer drugs. PAN-811 dose-dependently suppressed increased ROS and blocked the neurotoxicity when neurons were insulted with a tested anticancer drug. PAN-811 did not interfere with anticancer activity of anticancer drugs against BNLT3 cells. PAN-811 did not inhibit MTX-induced death of H460 cells but, interestingly, demonstrated a synergistic effect with 5-FU or CDDP in reducing cancer cell viability. Thus, PAN-811 can be a potent drug candidate for chemotherapy-induced cognitive impairment.

Prediction of methotrexate CNS distribution in different species - influence of disease conditions

Children and adults with malignant diseases have a high risk of prevalence of the tumor in the central nervous system (CNS). As prophylaxis treatment methotrexate is often given. In order to monitor methotrexate exposure in the CNS, cerebrospinal fluid (CSF) concentrations are often measured. However, the question is in how far we can rely on CSF concentrations of methotrexate as appropriate surrogate for brain target site concentrations, especially under disease conditions. In this study, we have investigated the spatial distribution of unbound methotrexate in healthy rat brain by parallel microdialysis, with or without inhibition of Mrp/Oat/Oatp-mediated active transport processes by a co-administration of probenecid. Specifically, we have focused on the relationship between brain extracellular fluid (brainECF) and CSF concentrations. The data were used to develop a systems-based pharmacokinetic (SBPK) brain distribution model for methotrexate. This model was subsequently applied on literature data on methotrexate brain distribution in other healthy and diseased rats (brainECF), healthy dogs (CSF) and diseased children (CSF) and adults (brainECF and CSF). Important differences between brainECF and CSF kinetics were found, but we have found that inhibition of Mrp/Oat/Oatp-mediated active transport processes does not significantly influence the relationship between brainECF and CSF fluid methotrexate concentrations. It is concluded that in parallel obtained data on unbound brainECF, CSF and plasma concentrations, under dynamic conditions, combined with advanced mathematical modeling is a most valid approach to develop SBPK models that allow for revealing the mechanisms underlying the relationship between brainECF and CSF concentrations in health and disease.

Controversies in primary CNS lymphoma

Primary CNS lymphoma is a non-Hodgkin's lymphoma confined to the CNS: the brain, eyes and cerebrospinal fluid. Unlike other primary brain tumors, primary CNS lymphoma is uniquely chemo- and radiosensitive. However, the outcome of primary CNS lymphoma patients is significantly inferior to similar non-Hodgkin's lymphoma patients. Multiple prospective studies using high-dose methotrexate, with or without whole-brain radiotherapy, have reported improved primary CNS lymphoma outcome, but numerous questions remain regarding the optimal care of a given patient.

Methotrexate area under the curve as a prognostic factor in primary central nervous system lymphoma treated with immunochemoradiotherapy

A higher methotrexate area under the curve (MTX AUC) observed during the first chemotherapy cycle has been associated with improved tumor control in patients with primary central nervous system lymphoma. To confirm these findings, we conducted a post hoc analysis of data from a prospective phase II trial of rituximab, methotrexate, procarbazine, vincristine, cytarabine, and low-dose radiotherapy. Thirty-nine patients were included (24 men; 15 women). The median age was 60 years (range 30-76) and median Karnofsky performance status (KPS) score was 70 (range 50-100). There was substantial inter-individual variability in MTX AUC (median: 795.5 µM*h/L, range 44.8-8326.44). However, there were no differences in progression-free survival (PFS) in patients below and above the median MTX AUC (2-year PFS 78% vs. 85% respectively; p = 0.51). Similarly, there were no differences in response rates or overall survival according to MTX AUC, suggesting that intra-patient dose escalation to increase MTX exposure is unnecessary when our regimen is utilized.

Hematology. Individualized methotrexate dosing in primary CNS lymphoma

Although high-dose methotrexate is widely accepted as the most effective chemotherapeutic agent for primary cns lymphoma, no optimal dose or dosing strategy has been established. Researchers from the International Extranodal Lymphoma Study Group used clinical trial data to explore whether or not an area under the curve model might be useful to optimize methotrexate dosing. The results strongly suggest that effective methotrexate dose is an important variable in patient outcome.

Chemotherapy in newly diagnosed primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) accounts for only 3% of brain tumors. It can involve the brain parenchyma, leptomeninges, eyes and the spinal cord. Unlike systemic lymphoma, durable remissions remain uncommon. Although phase III trials in this rare disease are difficult to perform, many phase II trials have attempted to define standards of care. Treatment modalities for patients with newly diagnosed PCNSL include radiation and/or chemotherapy. While the role of radiation therapy for initial management of PCNSL is controversial, clinical trials will attempt to improve the therapeutic index of this modality. Routes of chemotherapy administration include intravenous, intraocular, intraventricular or intra-arterial. Multiple trials have outlined different methotrexate-based chemotherapy regimens and have used local techniques to improve drug delivery. A major challenge in the management of patients with PCNSL remains the delivery of aggressive treatment with preservation of neurocognitive function. Because PCNSL is rare, it is important to perform multicenter clinical trials and to incorporate detailed measurements of long-term toxicities. In this review we focus on different chemotherapeutic approaches for immunocompetent patients with newly diagnosed PCNSL and discuss the role of local drug delivery in addition to systemic therapy. We also address the neurocognitive toxicity of treatment.

Therapeutic challenges in primary CNS lymphoma

Optimum treatment for patients with primary CNS lymphoma remains challenging because there have not been any large randomised clinical trials of this rare tumour. Drugs used in treating systemic non-Hodgkin lymphoma have mostly proven ineffective because of difficulties crossing the blood-brain barrier. The recognition of the efficacy of high-dose methotrexate was a substantial therapeutic breakthrough and further advances, such as the development of polychemotherapy regimens, have built on this. Whole-brain radiotherapy can consolidate response to chemotherapy, but the associated toxic effects of chemoradiation can be unacceptable. Other effective approaches include disruption of the blood-brain barrier and the use of high-dose chemotherapy. Recently, there have been attempts to optimise multi-drug chemotherapy regimens by focusing on improving survival and reducing toxic effects. A promising area of research is the incorporation of novel targeted drugs into standard treatment frameworks. In the future, greater cooperation between research groups should hopefully lead to further therapeutic advances.

Impact of the methotrexate administration dose on the need for intrathecal treatment in children and adolescents with anaplastic large-cell lymphoma: results of a randomized trial of the EICNHL Group

PURPOSE

To compare the efficacy and safety of two methotrexate doses and administration schedules in children with anaplastic large-cell lymphoma (ALCL).

PATIENTS AND METHODS

This randomized trial for children with ALCL was based on the Non-Hodgkin's Lymphoma-Berlin-Frankfurt-Muenster 90 (NHL-BFM90) study protocol and compared six courses of methotrexate 1 g/m2 over 24 hours and an intrathecal injection (IT) followed by folinic acid rescue at 42 hours (MTX1 arm) with six courses of methotrexate 3 g/m2 over 3 hours followed by folinic acid rescue at 24 hours without IT (MTX3 arm). This trial involved most European pediatric/lymphoma study groups and a Japanese group.

RESULTS

Overall, 352 patients (96% ALK positive) were recruited between 1999 and 2005; 175 were randomly assigned to the MTX1 arm, and 177 were assigned to the MTX3 arm. Ninety-two percent of patients received protocol treatment. Median follow-up time is 3.7 years. Event-free survival (EFS) curves were superimposed with 2-year EFS rates (73.6% and 74.5% in the MTX1 and MTX3 arms, respectively; hazard ratio = 0.98; 91.76% CI, 0.69 to 1.38). Two-year overall survival rates were 90.1% and 94.9% in MTX1 and MTX3, respectively. Only two CNS relapses occurred (both in the MTX1 arm). Toxicity was assessed after 2,050 courses and included grade 4 hematologic toxicity after 79% and 64% of MTX1 and MTX3 courses, respectively (P < .0001); infection after 50% and 32% of courses, respectively (P < .0001); and grade 3 to 4 stomatitis after 21% and 6% of courses, respectively (P < .0001).

CONCLUSION

The results of the NHL-BFM90 study were reproduced in this large international trial. The methotrexate schedule of the NHL-BFM90 protocol including IT therapy can be safely replaced by a less toxic schedule of methotrexate 3 g/m2 in a 3-hour infusion without IT therapy.

CNS prophylaxis in lymphoma: Who to target and what therapy to use

The purpose of this article is to review the current data on the risk of CNS relapse in patients with lymphoma and the efficacy of CNS directed prophylactic therapy. CNS relapse occurred in 30-50% of those with Burkitt lymphoma and acute lymphoblastic leukaemia/lymphoma prior to the introduction of intensified regimens that include CNS prophylaxis. Most patients with AIDS-related-lymphoma receive a short course of intrathecal prophylaxis but a re-evaluation of type and targeting of CNS prophylaxis is needed. Patients with diffuse large B-cell lymphoma (DLBCL) have a 5% overall risk of CNS relapse but a high risk sub-population can be identified on the basis of raised LDH and >1 extranodal site, testicular or primary breast involvement. CNS prophylaxis for selected patients with DLBCL may be justified by risk but its benefit is not yet proven. Intravenous methotrexate > or = 3 g/m(2) achieves therapeutic levels in CSF and parenchyma and in combination with intrathecal methotrexate would be a reasonable option for prophylaxis.

Treatment of mature B-ALL and high grade B-NHL in children

Burkitt Lymphoma and L3ALL are considered to be different forms of the same disease (B-cell disease). Tumour cells have similar cytological and immunological features and display the same non-random translocation involving c- myc on chromosome 8q24 and the gene of an immunoglobulin chain on chromosome 14, 2 or 22. Treatment outcome has greatly improved over the past 15 years as a result of multicentric national trials, especially in Europe, so that the disease has become curable in the majority of patients. Treatment is based on intensive polychemotherapy of short duration and adapted to tumour burden. The major drugs are cyclophosphamide, high-dose methotrexate and cytosine-arabinosine. CNS-directed therapy is essential. Supportive care is also important for the management of the acute treatment-related toxicity. A patient who remains for 1 year in complete remission can be considered as cured, because all relapses occur early within the first year after diagnosis.

Is intrathecal methotrexate necessary in the treatment of primary CNS lymphoma?

Systemic high-dose methotrexate (HD-MTX) is the most effective chemotherapeutic agent in the treatment of primary central nervous system lymphoma (PCNSL). Leptomeningeal involvement is common and intrathecal methotrexate (IT-MTX) is frequently used in combination with HD-MTX, but its benefits are not established. Using a case-controlled retrospective study, matching patients treated with HD-MTX with or without IT-MTX, we found no difference in survival, disease control, or neurotoxicity.

Pharmacotherapy of primary CNS lymphoma

Primary CNS lymphoma (PCNSL) is distinguished from other brain tumours by its striking response to chemotherapy. Surgery has little role (if any) in the treatment of PCNSL. Radiation therapy has been proven to prolong survival but its use is complicated by delayed neurological toxicity, particularly among the elderly. Progress in understanding the physiology of the blood-brain barrier (BBB) and the pharmacology of chemotherapeutic agents has substantially improved the treatment and prognosis of this disease. The single most effective agent is methotrexate (MTX). The goal of delivering an adequate dose of MTX to the brain and the cerebrospinal fluid (CSF) has been achieved by a variety of strategies, including systemic high dose, intra-arterial injection following pharmacological disruption of the BBB and intrathecal (it.) administration. MTX-based combination chemotherapy has yielded the best results to date but the prognosis of patients with PCNSL remains significantly worse than comparable patients with systemic non-Hodgkin's lymphoma (NHL). Ongoing trials continue to test novel combinations of agents, doses and improved routes of delivery with the hope of improving disease control and diminishing treatment-related neurotoxicity.

Variability in methotrexate serum and cerebrospinal fluid pharmacokinetics in children with acute lymphocytic leukemia: relation to assay methodology and physiological variables

Methotrexate (MTX) steady state concentrations were evaluated in 42 children who had received high-dose infusions (6-8 g/m2) for acute lymphocytic leukemia. Concentrations in serum and cerebrospinal fluid (CSF) measured by immunoassay were found to be highly variable. Reanalysis by a reference high-pressure liquid chromatography method ruled out analytical factors as a source of this variability. The correlation coefficient between the analytical methods was 0.77 for the serum data and 0.88 for the CSF data. The variability of serum and CSF concentrations was higher in younger patients (serum; P = 0.05 and CSF; P = 0.18), and the CSF concentration decreased with decreasing age and in later courses. Body surface area, body mass index, weight, and gender were not significantly related to MTX variability. We conclude that the pronounced pharmacokinetic variability seen during MTX infusions remains largely unexplained.

Primary central nervous system lymphoma: treatment with chemotherapy and radiotherapy

Between 1989 and 1993, 22 HIV negative patients with primary central nervous system lymphoma (PCNLS) were treated with three different regimens. In group A, 13 patients received preradiotherapy systemic and intrathecal methotrexate (MTX), radiotherapy (RT) and three courses of post-RT chemotherapy (CT) with thiotepa and procarbazine. In group B, 4 patients received a similar CT only after RT and without intrathecal MTX in 3/4 cases. In group C, 5 elderly patients received CT alone. In group A, 9/13 patients achieved response after pre-RT CT and 12/13 were in complete response (CR) after RT. After a median follow-up of 27 months, 8/13 (62%) patients are alive but 4 have leucoencephalopathy and cognitive dysfunction. In group B, all 4 patients were in CR after RT but the 3 patients who did not receive intrathecal MTX died within 10 months with meningeal recurrence. In group C, 4/5 patients had a response to CT. 2 patients died of recurrent tumour at 5 and 10 months, and 2 are living in CR 11+ and 21+ months after diagnosis, 1 after salvage CT. Combined treatment with RT and CT is useful in PCNSL but adequate treatment of the meninges is required. CT alone is sometimes of value in elderly patients in whom RT is not indicated.

Therapy of Burkitt and other B-cell acute lymphoblastic leukaemia and lymphoma: experience with the LMB protocols of the SFOP (French Paediatric Oncology Society) in children and adults

Burkitt's lymphoma and L3-ALL are different forms of the same disease: B-cell disease. Therapeutic improvement has been considerable over the past 10 years. In France, four consecutive multicentre LMB studies of the SFOP greatly contributed to this improvement. An overall cure rate of 90% can now be achieved in children with a short intensive risk adapted polychemotherapy regimen based on high-dose fractionated CPM, HD MTX (3 g/m2), Ara-C in continuous infusion. For patients with ALL or with CNS involvement, the addition of CNS-directed therapy with a higher dose of MTX (8 g/m2), HD Ara-C (3 g/m2 x 4), VP 16, triple intrathecal injections and cranial irradiation greatly improved survival: 87% for ALL and 73% for patients with CNS involvement. In adults, the application of the paediatric protocol is possible with acceptable toxicity and a retrospective study of 41 cases treated according to a LMB protocol showed a cure rate of 71%. Such a regimen should now be proposed to adults and studied prospectively.