Randomized comparison of 36-hour intermediate-dose versus 4-hour high-dose methotrexate infusions for remission induction in relapsed childhood acute lymphoblastic leukemia

Nanomedicine Applications in Treatment of Primary Central Nervous System Lymphoma: Current State of the Art

Primary central nervous system lymphoma (PCNSL) is a rare but highly aggressive subtype of extra nodal non-Hodgkin lymphoma (NHL), which is confined in the central nervous system (CNS). Despite recent advancements in treatment options, the overall prognosis of PCNSL remains poor. Among many unfavorable factors affecting efficacy, inadequate drug delivery into the CNS is still the thorniest challenge. Blood-brain barrier (BBB) constitutes a significant impediment, restricting entry of most therapeutics to the brain. Nanotechnology has offered great promise for brain diseases, as various nano-based drug delivery systems (NDDSs) have been developed for delivery of theranostic agents in to the CNS. These drug delivery systems possess significant advantages, including good feasibility, reliable safety profile, excellent BBB penetration and potent antitumor effects. As for treatment of PCNSL, numerous well-developed BBB-crossing nano-based strategies can be applied with proper modifications and improvements. Some exquisitely designed NDDSs specific for PCNSL have shown great potential. In this review, we provide a summary on current status of diagnosis and treatment of PCNSL, followed by an overview of BBB-crossing strategies applied in management of PCNSL, both novel and wellestablished. Finally, challenges and future perspectives in this field are also discussed.

Studies on the intracellular accumulation process of methotrexate and its correlation with the key protein using an LC-MS/MS method: a novel way to realize prospective individualized medication

High-dose methotrexate (HDMTX) combined with leucovorin (LV) is the first-line drug therapy for many kinds of malignant tumors. However, the specific treatment plans, such as dosage and duration of administration, are usually formulated according to the clinician's experience and therapeutic drug monitoring (TDM) of methotrexate in patients' plasma, which are responsible for strong individual differences of drug usage. A large number of studies have shown that methotrexate targets the inside of the cell. The key cytotoxic component is the methotrexate polyglutamates (MTXPGs) in the cell. The concentration of methotrexate in plasma does not reflect the efficacy and side effects well. Based on mass spectrometry technology, we developed and validated an accurate, sensitive, and stable method to quantify the intracellular MTX (MTXPG₁) and its metabolites MTXPG_2-7 simultaneously. The lower limit of quantification was 0.100 ng/ml, and the run time was only 3 min. Moreover, our team has already developed two LC-MS/MS-based methods to respectively quantify methotrexate in plasma samples and two key proteins (γ-glutamyl hydrolase [GGH] and folylpolyglutamate synthetase [FPGS]) in peripheral blood mononuclear cells (PBMC). Through these highly sensitive and accurate approaches, we have gained a deep understanding of the whole pharmacokinetic process of MTX and explored the key factors affecting the accumulation process of intracellular active components (MTXPGs). Based on this research, it is possible to find a more effective way to provide an accurate reference for clinical drug use than traditional therapeutic drug monitoring (TDM).

Folinic acid over rescue of high dose methotrexate: How problematic citations conserve discredited concepts

BACKGROUND

The outdated axiom that the dose of Folinic acid (FA) rescue used after high dose Methotrexate (HDMTX) should be kept to a minimum in order to prevent a reduction of prognosis ("over rescue") continues to be expressed even though the concept has been seriously challenged. Study aim The ways "problematic citations" are used to support an old theory, such as this, was examined.

RESULTS

Ten patterns of "problematic citation" use were identified. In 8 of these patterns the articles used were scientifically sound and the problem was with the articles citing them. However in 2 other pattens, the articles and their conclusions were flawed and citing them, apparently, resulted from accepting the presented data or conclusions as sound and valid. The patterns were 1. Claims based on data that are not present in the cited article. 2. Selective inclusion of data from cited articles. 3. Citation of misleading data presented only in the abstract. 4. Reporting trends as statistically significant. 5. Copying the citations used by others without checking the article. 6. Acceptance of illusionary truth in spite of knowledge to the contrary. 7. Citation of reports not relevant to the population under discussion 8. Presenting opinions as facts without any citation. 9. Selective presentation of data sets that support the thesis while ignoring the data sets that show the opposite results. 10. Use of a title expressing what the authors intended to show but not what was found.

IMPLICATIONS

The containing acceptance of this old insupportable conjecture, in part, because of "problematic citations" has resulted in unnecessary neurocognitive damage to patients and may have resulted in the misconception that it is the outcome of HDMTX that may have lead to its abandonment in favour of more toxic therapies. Realisation that this is a significant problem in data analysis should lead authors and reviewers to be even more carefully in checking all references. The importance of high-quality reviews is clearly evident. The effect of "Canonization of false facts" is a serious impairment to the acceptance of new hypotheses that better express reality and could lead to improved treatment results. Authors are advised only to cite articles they have read in entirety not relying on the title, abstract or previous use and to check the content of citations before submission.

The evaluation of red blood cell folate and methotrexate levels during protocol M in childhood acute lymphoblastic leukemia

BACKGROUND

After High-Dose Methotrexate (HD-MTX), folinic acid rescue therapy (Leucovorin) is administered to reduce side effects in pediatric acute lymphoblastic leukemia (ALL) patients. Leucovorin and MTX are structural analogues, possibly competing for cellular transport and intracellular metabolism. We hypothesize that Leucovorin accumulates during consecutive courses, which might result in a lower MTX uptake.

METHODS

We prospectively measured red blood cell (RBC) folate and MTX levels during four HD-MTX and Leucovorin courses in 43 patients treated according the DCOG ALL-11 protocol with 2-weekly HD-MTX (5 g/m²/dose) and Leucovorin (15 mg/m²/dose) using LC-MS/MS. We estimated a linear mixed model to assess the relationship between these variables over time.

RESULTS

Both RBC MTX-PG and folate levels increased significantly during protocol M. MTX-PG_2-5 levels increased most substantially after the first two HD-MTX courses (until median 113.0 nmol/L, IQR 76.8-165.2) after which levels plateaued during the 3^d and 4th course (until median 141.3 nmol/L, IQR 100.2-190.2). In parallel, folate levels increased most substantially after the first two HD-MTX courses (until median 401.6 nmol/L, IQR 163.3-594.2) after which levels plateaued during the 3^d and 4th course (until median 411.5 nmol/L, IQR 240.3-665.6). The ratio folate/MTX-PG decreased significantly over time, which was mostly due to the relatively higher increase (delta) of MTX-PG.

CONCLUSION

These results suggest that the increase in RBC folate levels does not seem to have a large effect on RBC MTX levels. Future studies, assessing competition of Leucovorin and MTX on other cellular mechanisms which might negatively affect treatment efficacy, are necessary.

A prospective, crossover randomized trial of the optimal timing for leucovorin rescue after high-dose methotrexate management in adult non-Hodgkin's lymphoma patients

This study aimed to investigate the optimal time of leucovorin rescue for HDMTX in non-Hodgkin's lymphoma (NHL) patients. Ninety-eight patients treated with HDMTX were randomly assigned to receive leucovorin at either 18 or 24 h after initiation of HDMTX infusion during the first cycle and switched to the other mode in the second cycle. All courses achieved an efficacious MTX concentration. Compared to the 18th hour group, the 24th hour group exhibited an increase in incidence of thrombocytopenia (48% versus 34.7%, p = .036) and grade III/IV neutropenia (34.7% versus 21.4%, p = .039). No bleeding occurred and the incidence of fever with grade III/IV neutropenia was low with no difference observed between the two groups. We recommend that with the HDMTX generally used most adult patients with NHL may have greater therapeutic benefit and acceptable toxicity with their LV rescue started at 24 h instead of 18 h.

Impact of Cisplatin Dosing Regimens on Mammary Tumor Growth in an Animal Model

Background

We have recently introduced a modification of the seminal Simeoni model for tumor growth, the modification entailing the incorporation of delay differential equations into its formulation. We found that the modification was competitive with the Simeoni construct in modeling mammary tumor growth under cisplatin treatment in an animal model.

Methods

In our original study, we had two cohorts of animals: untreated, and treatment with bolus injection of cisplatin on day 0. We here explore how modifications in the cisplatin dosing scheme affect tumor growth in our model.

Results

We found that modest fractionation dosing schemes have little ultimate impact on tumor growth. In contrast, metronomic dosing schemes seem quite efficacious, and might yield effective control over tumor progression.

Conclusions

With regard to cisplatin as single agent chemotherapy, a minimum level of drug for a prolonged period of time seems more critical than rapid achievement of a very high dose for a shorter time frame for deterring tumor growth or progression. Exploration of tumor dose schedules with mathematical models can provide valuable insights into potentially effective therapeutic regimens.

Leucovorin ameliorated methotrexate induced intestinal toxicity via modulation of the gut microbiota

Methotrexate (MTX) is a widely used therapeutic agent for the treatment of cancer and autoimmune diseases. However, its efficacy is often limited by adverse effects, such as intestinal toxicity. Although treatment with leucovorin (LV) is the most common method to reduce the toxic effects of MTX, it may also compromise the therapeutic effects of MTX. The gut microbiome has been reported to be associated with the intestinal toxicity of MTX. In this study, the intestinal damage of MTX was ameliorated by treatment with LV. Moreover, the population, diversity, and principal components of the gut microbiota in MTX-treated mice were restored by treatment with LV. The only element of the gut microbiota that was significantly changed after treatment with LV was Bifidobacterium, and supplementation with Bifidobacterium longum ameliorated MTX-induced intestinal damage. In conclusion, our results suggest that the balance and the composition of gut microbiota have an important role in the LV-mediated protection against MTX-induced intestinal toxicity. This work provides foundation of data in support of a new potential mechanism for the prevention of MTX-induced intestinal toxicity.

Changes in intracellular folate metabolism during high-dose methotrexate and Leucovorin rescue therapy in children with acute lymphoblastic leukemia

Background

Methotrexate (MTX) is an important anti-folate agent in pediatric acute lymphoblastic leukemia (ALL) treatment. Folinic acid rescue therapy (Leucovorin) is administered after MTX to reduce toxicity. Previous studies hypothesized that Leucovorin could ‘rescue’ both normal healthy cells and leukemic blasts from cell death. We assessed whether Leucovorin is able to restore red blood cell folate levels after MTX.

Methods

We prospectively determined erythrocyte folate levels (5-methyltetrahydrofolate (THF) and non-methyl THF) and serum folate levels in 67 children with ALL before start (T0) and after stop (T1) of HD-MTX and Leucovorin courses.

Results

Erythrocyte folate levels increased between T0 and T1 (mean ± SD: 416.7 ± 145.5 nmol/L and 641.2 ± 196.3 nmol/L respectively, p<0.001). This was due to an increase in 5-methyl THF levels (mean increase: 217.7 ± 209.5 nmol/L, p<0.001), whereas non-methyl THF levels did not change (median increase: 0.6 nmol/L [-9.9–11.1], p = 0.676). Serum folate levels increased between T0 and T1 (median increase: 29.2 nmol/L [32.9–74.0], p<0.001). Results were not significantly affected by age, sex, ALL immunophenotype and MTHFR c.677C>T genotype.

Conclusion

Intracellular folate levels accumulate after HD-MTX and Leucovorin therapy in children with ALL, suggesting that Leucovorin restores the intracellular folate pool. Future studies are necessary to assess concomitant lower uptake of MTX.

The effect of leucovorin rescue therapy on methotrexate-induced oral mucositis in the treatment of paediatric ALL: A systematic review

INTRODUCTION

This study aimed to determine the efficacy of different Leucovorin regimens to reduce oral mucositis in children with acute lymphoblastic leukemia after high-dose Methotrexate (HD-MTX).

METHODS

Twelve articles were included in a systematic literature review. Articles were categorized into low/medium/high risk of bias.

RESULTS

As no randomized controlled trial assessing the effect of Leucovorin has been performed, the efficacy of Leucovorin to reduce oral mucositis remains unknown. Leucovorin was initiated at 24, 36 or 42 h after HD-MTX at a dose of 15 or 30 mg/m². No meta-analysis could be performed as treatment regimens differed. When comparing studies with similar HD-MTX doses, we observed lower oral mucositis rates in regimens with higher cumulative doses of Leucovorin and early initiation of Leucovorin after MTX.

CONCLUSION

Even though future studies are necessary, higher cumulative Leucovorin doses and early initiation of Leucovorin after start of MTX seem to reduce oral mucositis.

Fish oil in comparison to folinic acid for protection against adverse effects of methotrexate chemotherapy on bone

Methotrexate (MTX) chemotherapy is known to cause bone loss which lacks specific preventative treatments, although clinically folinic acid is often used to reduce MTX toxicity in soft tissues. This study investigated damaging effects of MTX injections (0.75 mg/kg/day for 5 days) in rats and potential protective benefits of fish oil (0.25, 0.5, or 0.75 ml/100 g/day) in comparison to folinic acid (0.75 mg/kg) in the tibial metaphysis. MTX treatment significantly reduced height of primary spongiosa and volume of trabecular bone while reducing density of osteoblasts. Consistently, MTX reduced osteogenic differentiation but increased adipogenesis of bone marrow stromal cells, accompanied by lower mRNA expression of osteogenic transcription factors Runx2 and Osx, but an up-regulation of adipogenesis-related genes FABP4 and PPAR-γ. MTX also increased osteoclast density, bone marrow osteoclast formation, and mRNA expression of proinflammatory cytokines IL-1, IL-6, TNF-α, and RANKL/OPG ratio in bone. Fish oil (0.5 or 0.75 ml/100 g) or folinic acid supplementation preserved bone volume, osteoblast density, and osteogenic differentiation, and suppressed MTX-induced cytokine expression, osteoclastogenesis, and adipogenesis. Thus, fish oil at 0.5 ml/100 g or above is as effective as folinic acid in counteracting MTX-induced bone damage, conserving bone formation, suppressing resorption and marrow adiposity, suggesting its therapeutic potential in preventing bone loss during MTX chemotherapy.

How long can folinic acid rescue be delayed after high-dose methotrexate without toxicity?

To determine the optimal time of folinic acid rescue after methotrexate (MTX) treatment in patients with ALL, we selected and evaluated relevant studies that included doses, rescue delay, and side effects. Rescue at 42-48 hours resulted in considerable toxicity, except when low doses of MTX were used (1 g/m(2)) or serum MTX levels remained consistently low at 24, 30, and 36 hours. Rescue started at 30-36 hours was safe. In the absence of evidence that later rescue improves prognosis, we suggest that folinic acid rescue (105 mg/m(2)) be started no later than 36 hours from the start of MTX (5-6 g/m(2)).

Guideline on the prevention of secondary central nervous system lymphoma: British Committee for Standards in Haematology

The guideline group was selected to be representative of UK-based medical experts. Ovid MEDLINE, EMBASE and NCBI Pubmed were searched systematically for publications in English from 1980 to 2012 using the MeSH subheading 'lymphoma, CNS', 'lymphoma, central nervous system', 'lymphoma, high grade', 'lymphoma, Burkitt's', 'lymphoma, lymphoblastic' and 'lymphoma, diffuse large B cell' as keywords, as well as all subheadings. The writing group produced the draft guideline, which was subsequently revised by consensus by members of the Haemato-oncology Task Force of the British Committee for Standards in Haematology (BCSH). The guideline was then reviewed by a sounding board of ~50 UK haematologists, the BCSH and the British Society for Haematology (BSH) Committee and comments incorporated where appropriate. The 'GRADE' system was used to quote levels and grades of evidence, details of which can be found in Appendix I. The objective of this guideline is to provide healthcare professionals with clear guidance on the optimal prevention of secondary central nervous system (CNS) lymphoma. The guidance may not be appropriate to patients of all lymphoma sub-types and in all cases individual patient circumstances may dictate an alternative approach. Acronyms are defined at time of first use.

Challenging the clinical relevance of folinic acid over rescue after high dose methotrexate (HDMTX)

THE HYPOTHESIS

The use of adequate folinic acid rescue (in clinically relevant doses) after high dose methotrexate will prevent neurotoxicity without reducing treatment results.

METHODS

A literature search was performed to test the hypothesis that no evidence for the existence of folinic acid over-rescue of high-dose methotrexate (MTX) in clinically relevant situations exists (evidence that too much folinic acid reduced cure rate).

EMPIRICAL DATA

Examples of folinic acid over-rescue after lower doses of MTX were found and has been cited as evidence of over rescue of high dose MTX. Mega doses of folinic acid, used when toxic levels of MTX occurred, also could neutralize the MTX effect. Data were found to support the contention that higher levels of MTX require disproportionally higher folinic acid doses for rescue. Careful examination of the available studies after HDMTX yielded more convincing alternative explanations for reduction in cure rate than over rescue. Little convincing evidence for the existence of over rescue after HDMTX was found.

DISCUSSION

The rescue of high-dose MTX with an appropriate dose of folinic acid that can prevent toxicity, especially neurotoxicity, was not shown to reduce the therapeutic effect. No evidence was found that higher doses of folinic acid after high dose MTX reduces the therapeutic effect.

CONSEQUENCES OF THE HYPOTHESIS

Acceptance of the hypothesis can prevent harm being caused (especially brain damage) by reversing the trend of dose reduction in FA rescue. The recognition that the use of higher folinic acid doses is safe, can prevent neurotoxicity, and does not reduce prognosis has important implications for the development of effective non toxic treatment protocols.

Shortening infusion time for high-dose methotrexate alters antileukemic effects: a randomized prospective clinical trial

PURPOSE

To determine whether shortening the infusion duration of high-dose methotrexate (HDMTX; 1 g/m(2)) affects the in vivo accumulation of active methotrexate polyglutamates (MTXPG(1-7)) in leukemia cells and whether this differs among major acute lymphoblastic leukemia (ALL) subtypes.

METHODS

From June 2000 through October 2007, 356 children with ALL were randomly assigned to receive initial single-agent treatment with HDMTX (1 g/m(2)) as either a 24-hour infusion or a 4-hour infusion at two pediatric hospitals in the United States. The primary outcome measures were the accumulation of MTXPG(1-7) in leukemia cells and the antileukemic effects (eg, inhibition of de novo purine synthesis in bone marrow ALL cells, and decrease in circulating ALL cells).

RESULTS

The 24-hour infusion resulted in significantly higher amounts of MTXPG(1-7) in bone marrow leukemia cells (median: 1,695 v 1,150 pmol/10(9) cells, P = .0059), and better antileukemic effects. The 24-hour infusion had the greatest effect on MTXPG(1-7) accumulation in hyperdiploid ALL (median: 3,919 v 2,417 pmol/10(9) cells, P = .0038); T-cell ALL exhibited smaller differences in MTXPG(1-7) but greater antileukemic effects with the longer infusion (median decrease in leukemia cells: 88.4% v 51.8%, P = .0075). In contrast, infusion duration had no significant impact on MTXPG(1-7) accumulation or antileukemic effects in ALL with the t(12;21)/(ETV6-RUNX1) chromosomal translocation.

CONCLUSION

Shortening the infusion time of HDMTX reduces accumulation of active methotrexate in leukemia cells and decreases antileukemic effects, with differing consequences among major ALL subtypes.

Advances in individual prediction of methotrexate toxicity: a review

As the cure rates for haematological malignancies have improved, the exploration of the balance between efficacy and side effects has become a major research target. The antifolate methotrexate is widely used in the treatment of acute lymphoblastic leukaemia, non-Hodgkin lymphoma, and osteosarcoma. Even when given identical methotrexate doses, patients vary significantly in their response and pattern of toxicities. This diversity can, to some extent, be linked to sequence variations in genes involved in drug absorption, metabolism, excretion, cellular transport, and effector targets or target pathways. In the coming years pharmacogenomics is expected to change our approaches to individualised therapy with methotrexate. However, genetic polymorphisms affect the pharmacokinetics and dynamics of all the drugs a patient receive as well as the normal tissues tolerance to a given drug exposure. Thus, although high-throughput techniques will allow mapping of tens of thousands of genetic polymorphisms in one run, it will be a major challenge to dissect out which of these have the strongest impact on efficacy and toxicity and hence should be the targets for intervention. This paper discusses the pharmacology of methotrexate and reviews studies on haematological malignancies that have attempted to predict the risk of toxicity by specific clinical or genetic features.

The impact of acute lymphoblastic leukemia treatment on central nervous system results in Bogota, Colombia

To improve the outcome of children with acute lymphoblastic leukemia (ALL) treated at the National Cancer Institute, Bogota, Colombia, a protocol based on the BFM-90 (Berlin, Frankfurt, Munster study) and the LSA2L2 regimens was implemented in the year 1993. The patients were classified as being standard risk (SR) or high risk (HR) according to clinical criteria, to which cytogenetic information and day-8 prednisone response were also added. A 123-patient cohort entered the study, 18 of them being considered SR and 105 HR. There was a 94% 10 years' event-free-survival rate for the SR group and 36% for the HR group. Decreased induction death rate (7% vs. 14%), increased complete remission (CR) rate (81% vs. 75%), and continuous CR (45% vs. 33%) were found in comparison with the previous study. A significant improvement was achieved in relapse rate, 44% to 28% (P=0.029), mainly due to reduced central nervous system relapse rate from 16% to 6% (P=0.037), whereas the number of patients receiving cranial radiation was reduced to 55%. A major problem concerned the increased CR mortality rate, 5% to 14% (P=0.06). Improved supportive care therapy and socioeconomic conditions will hopefully reduce the CR mortality rate in the future.

High-dose compared with intermediate-dose methotrexate in children with a first relapse of acute lymphoblastic leukemia

High-dose methotrexate (MTX) has been extensively used for treatment of acute lymphoblastic leukemia (ALL). To determine the optimal dose of MTX in childhood relapsed ALL, the ALL Relapse Berlin-Frankfurt-Münster (ALL-REZ BFM) Study Group performed this prospective randomized study. A total of 269 children with a first early/late isolated (n = 156) or combined (n = 68) bone marrow or any isolated extramedullary relapse (n = 45) of precursor B-cell (PBC) ALL (excluding very early marrow relapse within 18 months after initial diagnosis) were registered at the ALL-REZ BFM90 trial and randomized to receive methotrexate infusions at either 1 g/m(2) over 36 hours (intermediate dose, ID) or 5 g/m(2) over 24 hours (high dose, HD) during 6 (or 4) intensive polychemotherapy courses. Intensive induction/consolidation therapy was followed by cranial irradiation, and by conventional-dose maintenance therapy. Fifty-five children received stem-cell transplants. At a median follow-up of 14.1 years, the 10-year event-free survival probability was .36 (+/- .04) for the ID group (n = 141), and .38 (+/- .04) for the HD group (n = 128, P = .919). The 2 groups did not differ in terms of prognostic factors and other therapeutic parameters. In conclusion, methotrexate infusions at 5 g/m(2) per 24 hours, compared with 1 g/m(2) per 36 hours, are not associated with increased disease control in relapsed childhood PBC acute lymphoblastic leukemia.

Prevention of high-dose-methotrexate neurotoxicity by adequate folinic acid rescue is possible even after central nervous system irradiation

Neurotoxicity, especially associated with therapy for acute lymphatic leukemia, has been attributed by many to the use of methotrexate (MTX). After radiotherapy this has been reported even more frequently but no explanation has been suggested apart from "a complex interaction". The hypothesis presented here is as follows: (1) Inadequate folinic acid rescue alone accounts for MTX-induced neurotoxicity. (2) Adequate folinic acid after MTX can prevent neurotoxicity. (3) Higher doses of MTX require a disproportionately higher dose of folinic acid than MTX to prevent toxicity. Doubling the dose of MTX has required tripling and quadrupling the folinic acid dose to prevent neurotoxicity. Assuming that central nervous system radiotherapy increases the cerebrospinal fluid levels of MTX and folinic acid proportionally, the folinic acid level may now not be enough to prevent neurotoxicity. This neurotoxicity occurs when MTX is given after (but not before) radiotherapy, and can be prevented by appropriate doses of folinic acid. (4) There is no evidence that within the dose range currently being used, the administration of larger quantities of folinic acid to prevent neurotoxicity compromises prognosis. This hypothesis is supported by a large amount of published data. Critical reanalysis of studies that ostensibly contradict parts of the hypothesis showed that they, in fact, support it.

High leucovorin doses during high-dose methotrexate treatment may reduce the cure rate in childhood acute lymphoblastic leukemia

We explored the relationship between time to relapse and different exposure variables (serum methotrexate (S-MTX) 23, 36 and 42 h after start of administration, MTX elimination time and leucovorin (LV) dose) during high-dose MTX (HDM) treatment of 445 children with acute lymphoblastic leukemia. MTX was infused at 5 g/m2 (non-high risk) or 8 g/m2 (high risk) over 24 h, 2-9 times per patient. LV rescue dose was adjusted according to the S-MTX concentration. Time from end of the last HDM to relapse was analyzed by Cox regression analysis with the logarithms of S-MTX and LV dose as exposures. The combined results from all risk groups suggest that high LV dose is related to higher risk for relapse. Doubling of the LV dose increased the relapse risk by 22% (95% confidence interval 1-49%, P = 0.037). High LV doses correlated with high MTX levels at 23, 36 and 42 h and longer elimination time. The results suggest that high doses of LV increase the risk for relapse despite the fact that they were correlated with high MTX levels and longer MTX elimination time. The choice of MTX and LV doses may be regarded as an intricate balance between effect and counter-effect.

High-Dose Methotrexate in Acute Lymphoblastic Leukemia: Where Is the Evidence for Its Continued Use?

High-dose intravenous methotrexate is an important component of many effective chemotherapeutic regimens for childhood acute lymphoblastic leukemia (ALL). Its use has a strong pharmacologic rationale: to overcome mechanisms of resistance of the malignant cells and to achieve cytotoxic concentrations in sanctuary sites for lymphoblasts. Although therapeutic progress in ALL during the past 4 decades has been closely associated with more widespread use of intravenous methotrexate and in progressively larger doses, little data exist to clearly support the use of high-dose intravenous methotrexate over a regimen of prolonged administration of low-dose methotrexate. The implied superiority of intravenous methotrexate mainly stems from studies that used identical leucovorin rescue with low-dose methotrexate or from studies of upfront window therapy in untreated children with ALL in which single standard doses of oral methotrexate were compared with high-dose intravenous methotrexate with leucovorin rescue. The evidence favoring administration of intravenous methotrexate for children with ALL is critically reviewed. Despite its extensive use, high-dose intravenous methotrexate has not been proved conclusively to be more effective than less toxic, less labor intensive, and less costly methods of methotrexate administration.

High-dose methotrexate therapy of childhood acute lymphoblastic leukemia: lack of relation between serum methotrexate concentration and creatinine clearance

BACKGROUND

The objectives of this study were: (1) to analyze the relation of serum methotrexate (MTX) concentration with creatinine clearance, (2) to compare the leucovorin rescue dose administered to the patients based on creatinine clearance, with the one calculated according to serum MTX levels, and (3) to determine MTX-related toxicity.

PROCEDURE

Thirty children with high-risk non-B acute lymphoblastic leukemia (ALL) treated according to the national protocol (PINDA 92) based on ALL BFM 90, were randomized to receive consolidation with four doses of either 1 or 2 g/m(2) MTX as a 24-hr infusion, at 2-week intervals (group M1 and M2, respectively). Serum MTX concentrations were measured at 24, 42, and 48 hr after beginning the infusion and were analyzed retrospectively. The creatinine clearance was calculated after 12-hr intravenous hydration prior to each MTX dose. Leucovorin dosage was adjusted according to creatinine clearance.

RESULTS

Serum MTX concentrations at 24, 42, and 48 hr after starting the infusion were not related to creatinine clearance in both treatment groups. Leucovorin rescue administered according to creatinine clearance was excessive in 43% in group M1 and in 51% in group M2, as compared to the dose calculated according to serum MTX levels. No serious clinical complications were observed.

CONCLUSIONS

These results suggest that creatinine clearance is not a good parameter to calculate leucovorin rescue. MTX-related toxicity in this group of patients receiving a dose of 1 or 2 g/m(2) and rescued with leucovorin without monitoring serum MTX levels was acceptable.

Defining the appropriate dosage of folinic acid after high-dose methotrexate for childhood acute lymphatic leukemia that will prevent neurotoxicity without rescuing malignant cells in the central nervous system

Neurotoxicity after the administration of methotrexate continues to worry physicians. However, inadequate folinic acid rescue is often not considered as a cause of this complication. To clarify whether adequate folinic acid rescue prevents methotrexate-induced neurotoxicity without reducing the cure rate in childhood ALL, published evidence that supported or refuted this claim was investigated. A literature search was conducted and the authors of the relevant studies were contacted. The published data supported the contention that neurotoxicity can be prevented by adequate folinic acid rescue even after very high doses of methotrexate. The safe minimum dose of folinic acid can be defined in terms of the dose of methotrexate given; the time to start of rescue is probably less important. There was no evidence that higher doses of folinic acid, such as those used after methotrexate in the treatment of osteosarcoma, rescue leukemia cells. No change in cure rate was found in relation to changes in scheduling or clinically relevant doses of folinic acid rescue. The accumulation of folinic acid in the cerebrospinal fluid did not seem to be of clinical relevance. No studies indicate that doses of folinic acid after high-dose methotrexate administration interfere with the killing of leukemia cells, nor that delaying the start of rescue beyond a certain point increases the antileukemic effect; neurotoxicity will, however, be increased. Review of current protocols that use low-dose folinic acid rescue and are associated with neurotoxicity is highly recommended.

Prevention and Treatment of Oropharyngeal Mucositis Following Cancer Therapy

Oropharyngeal mucositis is an acute and distressing toxic effect of chemotherapy and head and neck irradiation. This oral sequela significantly impairs the daily functioning and quality of life of patients. The biological basis of mucositis is quite complex, involving sequential interaction of chemotherapeutic drugs or irradiation on mitosis of proliferating epithelium, a number of cytokines, and elements of oral microbial environment. Various interventions based on biological attenuation have been tested for mucositis. Such interventions have been reviewed elsewhere; however, most reviews focus on biomedical outcomes. Little attention has been paid to mucositis outcomes with oral morbidity or psychosocial aspects. The purpose of this article is to review the current research studies on the prevention and treatment of oropharyngeal mucositis following chemotherapy, radiotherapy, and bone marrow transplantation with an emphasis on biomedical, oral symptomatic, and functional impairment outcomes. In addition, further avenues of mucositis management, including psychotherapeutic intervention and integrated and stage-based treatment approaches are discussed.

Pegylated asparaginase in combination with high-dose methotrexate for consolidation in adult acute lymphoblastic leukaemia in first remission: a pilot study

The German Multicentre acute lymphoblastic leukaemia (ALL) study group (GMALL) performed a pilot study using pegylated asparaginase (PEG-ASP) in combination with high-dose methotrexate as consolidation therapy in the 05/93 protocol. The aim of the study was an intra-individual comparison of two different doses of PEG-ASP in 26 patients, with regard to the depletion of asparagine in serum and toxicity. 'Pharmacokinetic' monitoring was performed to evaluate the effect of an intra-individual dose escalation of PEG-ASP from 500 to 1000 U/m2 intravenously in successive doses. Serum asparaginase activity was targeted at > or =100 U/l for 1 week and > or =50 U/l for 10 d. The second course of PEG-ASP was administered to 23 patients. Due to hypersensitivity reactions in five patients, only 18 patients were evaluable for pharmacokinetic monitoring. With respect to the PEG-ASP activity, an effective depletion of asparagine could be postulated in the majority of patients during 10 d after the first administration. The effect of an intraindividual dose escalation form 500 to 1000 U/m2 was evaluable in 17 of 22 patients. An increment in peak PEG-ASP activity >70% was observed in 65% of the patients. PEG-ASP was well tolerated. Despite the long half-life of PEG-ASP, neither pancreatic nor central nervous toxicities occurred among the 26 adult patients treated in this pilot study.

Dose reduction of coadministered 6-mercaptopurine decreases myelotoxicity following high-dose methotrexate in childhood leukemia

High-dose methotrexate (HDM) given concurrently with oral 6-mercaptopurine (6 MP) may be followed by myelotoxicity, which may necessitate treatment interruption and thus interfere with the efficacy of the treatment of childhood acute lymphoblastic leukemia (ALL). Through inhibition of purine de novo synthesis and enhancement of the bioavailability, HDM may increase the incorporation into DNA of 6-thioguanine nucleotides, the cytotoxic metabolites of 6 MP.A total of 26 children diagnosed 3/1996-4/2001 with ALL received five courses of HDM (5 g/m(2)/24 h with leucovorin rescue) at 8 weeks intervals during their first year of maintenance therapy with oral methotrexate (20 mg/m(2)/week) and 6MP (75 mg/m(2)/day). The dose of oral 6MP was reduced to a median of 51% (75% range: 39-62%, maximum 74%) of the standard dose from 2 weeks prior to until 2 weeks after HDM, because the previous HDM had led to a thrombocyte nadir < or =60 x 10(9)/l and/or a neutrophil nadir < or =0.7 x 10(9)/l. The 6MP dose reductions raised the median thrombocyte nadir following HDM from 46 x 10(9)/l (range: 6-214) to 133 x 10(9)/l (range: 21-305; P<0.001) and the median neutrophil nadir from 0.5 x 10(9)/l (range: 0.0-1.4) to 0.9 x 10(9)/l (range: 0.2-3.2; P<0.001). The effect of 6MP dose reductions was not significantly related to risk group, gender, age, or thiopurine methyltransferase genotype. With 6MP dose reductions, the median duration of treatment interruption following HDM was reduced from 8 to 0 days (P < 0.001). The reduction of 6MP dosage during HDM can significantly reduce the risk of severe myelotoxicity and prevent treatment interruptions.

CNS-directed therapy for childhood acute lymphoblastic leukemia: Childhood ALL Collaborative Group overview of 43 randomized trials

PURPOSE

A collaborative meta-analysis was performed to clarify the relative effects on relapse and survival of different types of therapies directed at the CNS in childhood acute lymphoblastic leukemia.

MATERIALS AND METHODS

Data were sought for each individual patient in all trials started in or before 1993 that included unconfounded randomized comparisons of such treatments. Log-rank survival analyses were performed for each trial, and overall results for groups of trials addressing similar questions were obtained from the totals of the observed minus expected number of events and their variances.

RESULTS

Radiotherapy and long-term intrathecal therapy gave similar outcomes, with no significant difference in event-free survival despite random assignment of treatment to 2,848 patients, 1,001 of whom suffered relapse or death. Intravenous methotrexate reduced non-CNS rather than CNS relapses, and hence, the addition of intravenous methotrexate to a treatment regimen including radiotherapy or long-term intrathecal therapy improved event-free survival, with a 17% reduction in the event rate (95% confidence interval, 6% to 27%; P =.003). The event-free survival at 10 years in these trials was 61.9% without intravenous methotrexate and 68.1% with intravenous methotrexate. There was no significant difference in survival (14% death rate reduction; P =.09). There were insufficient randomly assigned patients to adequately address other questions, such as effect of different doses. No evidence was found of differences, between trials or between subgroups of different types of patients, in the relative effects of treatment.

CONCLUSION

Radiotherapy can be replaced by long-term intrathecal therapy. Intravenous methotrexate gives some additional benefit by reducing non-CNS relapses.

High-dose methotrexate: on the relationship of methotrexate elimination time vs renal function and serum methotrexate levels in 1164 courses in 264 Swedish children with acute lymphoblastic leukaemia (ALL)

PURPOSE

The objectives of the present study were to determine the relationship between methotrexate (MTX) elimination time and various aspects of renal function and to evaluate the prognostic value of elevated serum MTX and creatinine for delayed MTX elimination.

PATIENTS AND METHODS

The majority of the 264 children were being treated for ALL. According to the NOPHO-92 protocol, 5 or 8 g MTX/m(2) was administered over 24 h. Serum creatinine was assessed daily. In 11 patients from one centre, renal function was studied in more detail using serum cystatin C, iohexol clearance, and urinary albumin, IgG and protein HC.

RESULTS

Increased serum creatinine correlated significantly with the elimination time of MTX, whereas no indications were found of tubular or barrier function damage. Of the 1164 courses, 44 had delayed elimination of MTX (>/=120 h). Serum MTX >150 microM at the end of infusion had a sensitivity of 0.27 and a specificity of 0.94 to predict delayed MTX elimination, and >/=50% increase in serum creatinine during the first treatment day (creatinine ratio) had a sensitivity of 0.32 and a specificity of 0.99. The corresponding risk ratios were 5 and 19 for MTX >150 micro M and creatinine ratio, respectively. In courses with a normal elimination time (<72 h), 99% of the courses had a rise in serum creatinine of less than 50%.

CONCLUSIONS

Elevation of serum creatinine by more than 50% is a better predictor of delayed elimination than the level of serum MTX at the end of MTX infusion, especially if information on previous creatinine measurements is used to reduce the impact of an occasionally low serum creatinine value before the start of the MTX infusion.

Intermediate-dose methotrexate and intravenous 6-mercaptopurine chemotherapy for children with acute lymphoblastic leukemia who did not respond to initial induction therapy

PURPOSE

To determine the complete remission rate of children with acute lymphoblastic leukemia (ALL) who were not induced into remission by initial therapy, when subsequently treated with intermediate-dose methotrexate and intravenous 6-mercaptopurine.

PATIENTS AND METHODS

Children with B-precursor ALL who did not achieve initial remission after 4 or 6 weeks of standard three- or four-drug induction chemotherapy were entered on study. Therapy consisted of three doses at weekly intervals of methotrexate 1,000 mg/m2 over 24 hours followed by 6-mercaptopurine 1,000 mg/m2 over 8 hours 20 minutes. Patients achieving a partial remission could receive two additional weekly courses of methotrexate and 6-mercaptopurine. Initially, patients received weekly intrathecal chemotherapy, but the study was amended to include intrathecal therapy only at week 1.

RESULTS

Nineteen patients were entered on study. All were evaluable for toxicity and response. There were seven complete remissions, four partial remissions, six patients with no response, and two children with progressive disease, for an overall complete remission rate of 37%. One patient was removed from the study after the second course of methotrexate and 6-mercaptopurine because of renal failure. Two patients had neurologic toxicity resulting in a study amendment. No patients subsequently experienced neurologic toxicity.

CONCLUSIONS

Intermediate-dose intravenous methotrexate and intravenous 6-mercaptopurine can induce remission in some patients with ALL who experience initial induction failure. Features predicting complete remission, however, could not be identified.

A phase I study of nolatrexed dihydrochloride in children with advanced cancer. A United Kingdom Children's Cancer Study Group Investigation

A phase I study of nolatrexed, administered as a continuous 5 day intravenous infusion every 28 days, has been undertaken for children with advanced malignancy. 16 patients were treated at 3 dose levels; 420, 640 and 768 mg/m(2)24 h(-1). 8 patients were evaluable for toxicity. In the 6 patients treated at 768 mg/m(2)24 h(-1), dose-limiting oral mucositis and myelosuppression were observed. Plasma nolatrexed concentrations and systemic exposure, measured in 14 patients, were dose related, with mean AUC values of 36 mg(-1)ml(-1)min(-1), 50 mg ml(-1)min(-1)and 80 mg ml(-1)min(-1)at the 3 dose levels studied. Whereas no toxicity was encountered if the nolatrexed AUC was <45 mg ml(-1)min(-1), Grade 3 or 4 toxicity was observed with AUC values of >60 mg ml(-1)min(-1). Elevated plasma deoxyuridine levels, measured as a surrogate marker of thymidylate synthase inhibition, were seen at all of the dose levels studied. One patient with a spinal primitive neuroectodermal tumour had stable disease for 11 cycles of therapy, and in two patients with acute lymphoblastic leukaemia a short-lived 50% reduction in peripheral lymphoblast counts was observed. Nolatrexed can be safely administered to children with cancer, and there is evidence of therapeutic activity as well as antiproliferative toxicity. Phase II studies of nolatrexed in children at the maximum tolerated dose of 640 mg/m(2)24 h(-1)are warranted.

Chemotherapy-induced oral mucositis. Prevention and management

Oral mucositis is a frequent and potentially severe complication of chemotherapy which has a considerable impact on patient quality of life. While the management of other chemotherapy-related toxicities has improved, the incidence of mucositis is increasing. A critical review of the literature published between 1985 and 1999 reveals very few strategies or agents with proven efficacy, leaving few recommendations for the standard care in the prevention and treatment of mucositis at this time. Recommendations that can be made include: reducing patient risk factors, implementing proven preventative interventions such as utilising oral ice chips with fluorouracil chemotherapy, and optimising supportive care practices individualised to the patients' needs and symptoms. Progress in understanding the pathophysiology of mucositis at the molecular level has led to the evaluation of a number of new investigational agents, specifically those directed to the epithelial mucosa, such as mitogens and epithelial growth factors. These appear to be very promising in preclinical studies. Randomised clinical trials with these agents may finally demonstrate an impact on the clinical practice of mucositis management in the coming years.

Prevention and treatment of chemotherapy- and radiotherapy-induced oral mucositis: a review

Oral mucositis is a distressing toxic effect of systemic chemotherapy with many commonly utilized drugs and of head and neck irradiation in patients with cancer. The agents and methods that have been used and studied in chemotherapy- and radiotherapy-induced oral mucositis, their mechanisms of action, and the current knowledge of their efficiency to reduce the incidence, severity or shorten the duration of oral mucositis are reviewed in this article. Oral cooling is a cheap and available method to lower the severity of bolus 5-fluorouracil-induced oral mucositis. However, more effective methods are needed. Results of studies with granulocyte-macrophage colony-stimulating factor or granulocyte colony-stimulating factor are promising. Lasers are partly beneficial, but equipment-demanding. Modification of the chemotherapy regimen resulting in shortening of the exposition time to chemotherapy agents or chronomodulation of chemotherapy has been shown to lower mucosal toxicity of some regimens. Results of animal studies with locally applied transforming growth factor beta 3 and interleukin-11 are also promising. Based on the findings of the role of the inflammatory cascade in the response of normal tissues to chemotherapy and radiotherapy, anti-inflammatory drugs might be beneficial. At the present time, no agent has been shown to be uniformly efficacious and can be accepted as standard therapy of chemotherapy- and radiotherapy-induced oral mucositis. Further intensive research is needed.

Acute lymphoblastic leukemia in children: nonrandomized comparison of conventional vs. intensive chemotherapy at the National Cancer Institute of Colombia

BACKGROUND

This study aimed to compare the therapeutic efficacy of two treatments for childhood acute lymphoblastic leukemia (ALL), and to evaluate the feasibility of intensive chemotherapy in a developing country.

METHODS

The study was conducted at the National Cancer Institute in Bogota, Colombia. Untreated ALL patients under 16 years of age were divided into two groups: a historical control cohort (HC) of 141 patients treated with conventional chemotherapy and an intensive chemotherapy cohort (IC) of 130 patients treated with a modified Berlin-Frankfurt-Münster protocol (m-BFM). Patients were clinically classified into risk categories for relapse, and followed through July 31, 1995. Disease-free survival (DFS) curves were obtained using the Kaplan-Meier method and were compared by the log rank test.

RESULTS

Therapy groups had similar clinical baseline characteristics. Nonresponse rate to induction was higher in the HC group (16.3%) than in the IC cohort (7.6%) (P = 0.047), but deaths during induction were more frequent among m-BFM patients (13.8%) than in the HC group (6.4%) (P = 0.064). Bone marrow relapses after complete remission were less common in the IC group than in the HC group (19.4% and 45.9%, respectively; P = 0.0001), but central nervous system relapses showed no difference (12.8% in the HC and 16.3% under IC; P = 0.6). The DFS rates at 10 years were higher for the IC group, regardless of the baseline risk.

CONCLUSIONS

IC reduces the frequency of relapses in ALL children in developing countries, when compared to previous therapy. A highly effective therapy such as m-BFM seems to be the most important predictor of outcome in children.