High-dose Methotrexate Treatment Research Articles

Genetic polymorphisms as predictors of methotrexate toxicity: literature review

Background. A significant advancement in the treatment of high-grade aggressive non-Hodgkin’s lymphomas and acute lymphoblastic leukemia is the inclusion of high-dose (1000–5000 mg/m2) methotrexate in the treatment protocol. This approach has significantly increased the long-term survival rate, but it has been associated with toxicity, requiring supportive care. Factors that predict toxicity were identified, including genes involved in the metabolism (MTHFR) or transport (SLCO1B1) of methotrexate. The analysis of methotrexate metabolism has identified additional genes responsible for the elimination of this drug, allowing for more effective prevention and treatment of methotrexate-associated toxicity.Aim. To study the genetic polymorphisms of enzymes involved in the methotrexate metabolism and associated toxicity in the treatment of pediatric acute lymphoblastic leukemia and non-Hodgkin’s lymphomas.Materials and methods. Data were analyzed in specialized medical databases such as Pubmed, Scopus, Web of Science, Frontiers, and Google Scholar from 2001 to 2024.Results. The main predictors of high-dose methotrexate-associated toxicity are gene polymorphisms in MTHFR, SLCO1B1, ARID5B.Conclusion. Despite the contradictory data presented in the literature, it is important to consider the detection of polymorphisms during high-dose methotrexate treatment in order to administer timely supportive care and prevent significant toxicity.

Involvement of the ABCB1 C3435T Variant but Not the MTHFR C677T or MTHFR A1298C Variant in High-Dose Methotrexate-Induced Toxicity in Pediatric Acute Lymphoblastic Leukemia Patients in China.

It remains unclear whether the MTHFR C677T, MTHFR A1298C and ABCB1 C3435T genetic variants are associated with methotrexate (MTX) elimination delay and high-dose MTX (HD-MTX) toxicities in the treatment of pediatric acute lymphoblastic leukemia (ALL). The aim of our study was to analyze the potential predictive role of MTHFR C677T, MTHFR A1298C and ABCB1 C3435T in toxicities and the relationship between these variants and MTX elimination delay during HD-MTX therapy in pediatric ALL patients. We conducted a retrospective study on ALL patients receiving HD-MTX treatment with available MTHFR C677T, MTHFR A1298C and ABCB1 C3435T genotype and 44-h plasma MTX levels. Logistic regression analyses and chi-square tests were used to assess the relationship between the variants and HD-MTX toxicities and MTX elimination delay. Genotype frequencies were in Hardy-Weinberg equilibrium. MTX elimination delay did not significantly differ between MTHFR C677T and MTHFR A1298C or ABCB1 C3435T. Leukopenia (P=0.028), neutropenia (P=0.034) and oral mucositis (P=0.023) were 6.444-fold, 4.978-fold and 9.643-fold increased, respectively, in ABCB1 C3435T homozygous genotype (TT) patients compared to wild-type (CC) patients. No significant association was found between the toxicities investigated and MTHFR C677T or MTHFR A1298C. This study showed that the ABCB1 C3435T homozygous allele genotype (TT) is associated with increased MTX-related toxicities (leukopenia, neutropenia and oral mucositis). These results may help to distinguish pediatric ALL patients with a relatively high risk of MTX-related toxicities before HD-MTX infusion and optimize MTX treatment.

Improving measured health-related quality of life with outpatient high-dose methotrexate regimen among oncology patients with intracranial metastases: A systematic assessment

Intracranial metastases including leptomeningeal disease are not uncommon in patients with metastatic solid tumor cancers, such as breast and sarcoma. Treatment options are limited with disease progression on standard-of-care therapies, and high-dose Methotrexate (MTX) is offered for patients with well-preserved performance status. However, standard high-dose MTX treatment entails a lengthy hospitalization and close monitoring which can limit Quality of Life (QoL) for patients who already have multiple provider visits. The impact of high-dose MTX on patients’ daily lives has not yet been qualitatively examined. As a quality improvement project, our team designed an outpatient high-dose protocol for patients who tolerated at least one cycle of inpatient high-dose MTX, and herein we describe the protocol and a quality survey with patients’ feedback. The purpose of this study is to explore and compare the influence of high-dose MTX treatments in two different settings – inpatient and ambulatory – on patients’ QoL. Second, we aim to identify recurrent themes defining patients’ perceived QoL and healthcare experiences. This study identified key QoL impacts that high-dose MTX treatments have on metastatic breast and sarcoma patients. Patients experienced decreased health-related burdens and improved social and psychosocial well-being associated with high-dose MTX treatment compared to standard inpatient treatment. This study provides an opportunity to identify recurrent thematic domains defining QoL in women with metastatic breast cancer.

Development of a Novel Nomogram for Predicting Delayed Methotrexate Excretion in Adult Patients with Hematologic Malignancies

Introduction: High-dose methotrexate (HD-MTX) is an essential regimen for the treatment or prevention of central nervous system disease in hematologic malignancies. However, delayed MTX excretion is a major contributor to increased MTX toxicity and limits its use in populations such as younger individuals with good kidney function. Given the variable degrees of older age and poor renal function, there is a need to focus on developing a more precise predictive tool for delayed MTX excretion rather than avoiding HD-MTX treatment in all patients considered relatively high-risk. The aim of this study is to identify risk factors for delayed MTX excretion in adult patients with hematologic diseases and establish an applicable model for clinical practice. Methods: We performed a retrospective analysis of consecutive patients with acute leukemia or malignant lymphoma who received HD-MTX therapy at Kameda Medical Center between 2011 and 2023. Standard supportive care, such as adequate hydration, urine alkalinization (pH >7.0), and leucovorin rescue, was performed according to our institutional protocol. Delayed MTX excretion was defined as plasma MTX levels ≥ 1 μmol/L at 48 h or ≥ 0.1 μmol/L 72 h after HD-MTX infusion. Univariate and multivariate analyses using logistic regression were performed to identify risk factors for delayed MTX excretion. Variables to create a nomogram was selected using a backward stepwise selection method. The internal validation of the nomogram was conducted using the bootstrap method (1000 bootstrap resample). Results: A total of 216 patients were treated with 579 cycles (median 2, range 1-14) of HD-MTX-containing chemotherapy. The median age was 66 years (range 15-84), with male predominance (58.3%). Most patients (82.9%) had an underlying malignant lymphoma, and most cycles were administered at diagnosis (81%) and for prophylactic intent (76.4%). The delayed MTX excretion occurred 129 in 579 cycles (22.2%); 39 (30.2%) at 48 hours and 107 (82.9%) at 72 hours after MTX infusion, and 17 (13.2%) at both time points. On univariate analysis, neither the dose of MTX nor the dosing formula (3 hours drip or 24-hour continuous infusion) was a significant risk factor for MTX elimination failure. By contrast, older age (Odds ratio [OR] 1.022, 95% confidence interval [CI] 1.006-1.039, P =0.009), male sex (OR 1.6 [1.05-2.42], P =0.027), levels of albumin (OR 0.44 [0.302-0.639], P <0.001), creatinine clearance (Ccr) (OR 0.99 [0.985-0.998]), gamma-glutamyl transpeptidase (γ-GTP) (OR 1.004 [1.001-1.007], P =0.005), and corrected calcium (cCa) (OR 2.746 [1.646-4.651], P <0.001) significantly associated with MTX clearance. Using backward stepwise selection, sex, albumin, Ccr, γ-GTP, and cCa were selected as continuous variables to create a nomogram (Figure 1). The nomogram showed the area under the curve of 0.69 (95%CI 0.64-0.74) in predicting delayed MTX excretion (Figure 2) without significant overfitting (optimism =0.091). Finally, we evaluated the impact of MTX elimination failure on clinical outcomes. As expected, delayed MTX excretion was highly associated with the development of any grade acute kidney injury (OR 30.9 [10.6-90.1], P <0.001). Patients who experienced a delay in MTX clearance had significantly worse survival after receiving HD-MTX than those without (5-year survival rate 38% vs. 64.5%, P <0.001). This negative effect remained significant (hazard ratio 1.73 [1.08-2.78], P =0.02) after adjusting age and disease status on multivariate analysis. Conclusions: To our knowledge, this is the first study to construct an easy-to-use nomogram based on routinely measured biochemical data and gender predicting the risk of delayed MTX excretion. Further studies are needed to validate this model and integrate the dynamic factors such as urine output and alkalinization.

Wearable Microneedle-Based Array Patches for Continuous Electrochemical Monitoring and Drug Delivery: Toward a Closed-Loop System for Methotrexate Treatment.

Wearable devices based on microneedle (MN) technology have recently emerged as tools for in situ transdermal sensing or delivery in interstitial fluid (ISF). Particularly, MN-based electrochemical sensors allow the continuous monitoring of analytes in a minimally invasive manner through ISF. Exogenous small molecules found in ISF such as therapeutic drugs are ideal candidates for MN sensors due to their correlation with blood levels and their relevance for the optimal management of personalized therapies. Herein, a hollow MN array patch is modified with conductive pastes and functionalized with cross-linked chitosan to develop an MN-based voltammetric sensor for continuous monitoring of methotrexate (MTX). Interestingly, the chitosan coating avoids biofouling while enabling the adsorption of MTX at the electrode's surface for sensitive analysis. The MN sensor exhibits excellent analytical performance in vitro with protein-enriched artificial ISF and ex vivo under a Franz diffusion cell configuration. The MN sensor shows a linear range from 25 to 400 μM, which fits within the therapeutic range of high-dose MTX treatment for cancer patients and an excellent continuous operation for more than two days. Moreover, an iontophoretic hollow MN array patch is developed with the integration of both the anode and cathode in the single MN array patch. The ex vivo characterization demonstrates the transdermal on-demand drug delivery of MTX. Overall, the combination of both MN patches represents impactful progress in closed-loop systems for therapeutic drug management in disorders such as cancer, rheumatoid arthritis, or psoriasis.

A-126 Evaluation of NMR-based GFR Estimation in Dosing of High-dose Methotrexate

Abstract Background The cytotoxic agent methotrexate (MTX) is mainly used in oncology and rheumatology. MTX is 80%–90% excreted unchanged in the urine, thus, impaired renal excretion because of kidney disease leads to accumulation and prolonged exposure, with a consequent increased risk of myelosuppressive and other toxic adverse effects. Direct kidney damage from MTX crystal precipitation and tubular injury may also occur. Therefore, precise and accurate measurement of renal function prior to MTX administration is of paramount importance to determine accurate dosing and to minimize such adverse risks. Commonly used estimated glomerular filtration rate (eGFR) equations perform poorly in patients with cachexia and at later stages of life—the typical oncology patient. Here we evaluate the feasibility of applying the recently introduced nuclear magnetic resonance (NMR)-based GFR equation (GFRNMR) using creatinine, cystatin C, myo-inositol, and valine, in oncology patients receiving high-dose MTX. Methods A series of residual sera from patients scheduled to receive high-dose MTX infusion for oncological indications were collected from two sites: n = 52 sera from the University Hospital Regensburg (Regensburg, Germany), at four time points (t0h, t24h, t42h, and t48h), and n = 10 cross-sectionally from the Mayo Clinic (MN). Standard drug-monitoring trough levels were used as a reference. Serum was prepared and NMR-measured in five replicates for all samples. GFRNMR was compared with the current standard GFR equations: i) CKD-EPI2021Cr (creatinine) and ii) CKD-EPI2021CrCys (creatinine and cystatin-C). Coefficient of determination for linear regression, kappa coefficient for categorical regression and bootstrapped confidence intervals were calculated. Results MTX was shown not to increase the GFRNMR failure rate or affect the intra-assay precision of GFRNMR. When monitoring eGFR during high-dose MTX treatment, MTX affected GFR according to the RIFLE criteria for AKI in 13 cycles in 9 patients; 1/13 were classified as ‘risk’ (creatinine increased 1.5-fold) and 1/13 were classified as ‘injury’ (creatinine increased 2.0-fold). Using MTX clearance as a surrogate for measured GFR, GFRNMR was shown to reflect the MTX plasma clearance constant k more accurately (using a fitting function c = c0*e−kt) with r = 0.758 (95% CI 0.36–0.92, P = 0.004) compared to CKD-EPI2021Cr (r = 0.401, 95%CI −0.19–0.78, P = 0.176) and CKD-EPI2021CrCyc (r = 0.632, 95% CI 0.12–0.88). Conclusion The robustness of GFRNMR test results is not affected by HD-MTX treatment. Compared to standard eGFR equations, GFRNMR is more closely associated with MTX renal clearance rates and may therefore be a novel method to improve the accuracy of MTX dosing in the future.

Fluorescent immunochromatographic test strip for therapeutic drug monitoring of methotrexate with high sensitivity and wide dynamic range.

As a front-line chemotherapeutic drug for maintenance and consolidation therapy, methotrexate (MTX) has widely been applied to treat various tumors and some inflammatory diseases. However, because of its severe toxicity ascribed to low selectivity, it is necessary to monitor therapeutic drugs in high-dose MTX therapeutic regimens to ensure treatment safety. In this work, we developed a fluorescent immunochromatographic test strip (FITS) for monitoring MTX by employing time-resolved fluorescent microspheres as signal probes. With a competitive immunoassay mode, the FITS for MTX shows a super-wide dynamic range of 10pM-10μM, covering the entire clinical therapeutic concentration range of MTX. Therapeutic drug monitoring of MTX can be achieved within 7min with high specificity, facilitating the timely rescue of drug poisoning led by high-dose MTX treatment. The methodwasemployedfor monitoring MTX in the spiked human serum, urine, and milk, showing acceptable recoveriesranging from 94.0 to 110.0%. The established FITS has been applied toMTX detection in serum obtained from high-dose MTX treatment. The results from FITS and enzyme multiplied immunoassay technique showed no significant difference, suggesting its reliability for usage in real biological samples. The device shows promise in point-of-caretherapeutic drug monitoring for resource-limited countries and institutes, which significantly facilitates overcoming the lag time between sampling and results.

Effect of co-medications and potential risk factors of high-dose methotrexate-mediated acute hepatotoxicity in patients with osteosarcoma.

Taiwanese patients frequently experience severe hepatotoxicity associated with high-dose methotrexate (HD-MTX) treatment, which interferes with subsequent treatment. Drug-drug interactions occur when MTX is used in combination with proton pump inhibitors (PPIs), trimethoprim-sulfamethoxazole (TMP-SMX), or non-steroidal anti-inflammatory drugs (NSAIDs). In East Asia, real-world analyses on the effects of co-medication and other potential risk factors on the clinical course of HD-MTX-mediated acute hepatotoxicity in patients with osteogenic sarcoma (OGS) are limited. This cohort study included patients with newly diagnosed OGS who were treated with HD-MTX between 2009 and 2017 at Taipei Veterans General Hospital. We collected data on the clinical course of HD-MTX-mediated acute hepatotoxicity, co-medications, and other potential risk factors, and analyzed the effects of these factors on the clinical course of HD-MTX-mediated acute hepatotoxicity. Almost all patients with OGS treated with HD-MTX developed acute hepatotoxicity with elevated alanine aminotransferase (ALT) levels. Most patients with Grade 3-4 ALT elevation failed to recover to Grade 2 within 7 days. Women and children are high-risk subgroups for HD-MTX-mediated elevation of ALT levels. Age is a factor that contributes to the pharmacokinetic differences of HD-MTX. However, the concurrent use of PPIs, TMP-SMX, or NSAIDs did not affect the elimination of MTX when administered with adequate supportive therapy. Co-administration of PPIs, TMP-SMX, or NSAIDs may have limited effects on acute hepatotoxicity in well-monitored and adequately pre-medicated patients with OGS undergoing chemotherapy with HD-MTX. Clinicians should pay particular attention to ALT levels when prescribing HD-MTX to children and women.

Hepatotoxicity from high-dose methotrexate in primary central nervous system lymphoma.

High-dose methotrexate (HDMTX) is a mainstay of primary central nervous system lymphoma (PCNSL) treatment. Transient hepatotoxicity from HDMTX has been characterized in pediatric patients but not in adults. We sought to characterize hepatotoxicity in adult PCNSL patients undergoing HDMTX treatment. Retrospective study of 65 PCNSL patients treated at the University of Virginia from 02/01/2002 to 04/01/2020 was performed. Hepatotoxicity was defined using National Cancer Institute Common Toxicity Criteria (CTC) for adverse events, fifth version. High-grade hepatotoxicity was defined as a bilirubin or aminotransferase CTC grade of 3 or 4. Relationships between clinical factors and hepatotoxicity were assessed with logistic regression. Most patients (90.8%) had a rise of at least one aminotransferase CTC grade during HDMTX treatment. 46.2% had high-grade hepatotoxicity based on aminotransferase CTC grade. No patients developed high-grade bilirubin CTC grades during chemotherapy. Liver enzyme test values decreased to low CTC grade or normal in 93.8% of patients after the conclusion of HDMTX treatment without treatment regimen changes. Prior ALT elevation (P = .0120) was a statistically significant predictor of high-grade hepatotoxicity during treatment. Prior history of hypertension was associated with increased risk of toxic serum methotrexate levels during any cycle (P = .0036). Hepatotoxicity develops in the majority of HDMTX-treated PCNSL patients. Transaminase values decreased to low or normal CTC grades in almost all patients after treatment, without modification of MTX dosage. Prior ALT elevation may predict patients' increased hepatotoxicity risk, and hypertension history may be a risk factor for delayed MTX excretion.

Acute Kidney Injury with SARS-CoV-2 Infection in Pediatric Patients Receiving High-Dose Methotrexate Chemotherapy: A Report of Three Cases

Methotrexate is renally excreted. HDMTX (high dose-methotrexate)-induced acute kidney injury (AKI) is a non-oliguric decrease in glomerular filtration rate (GFR) heralded by an acute rise in serum creatinine. Moreover, AKI is also a frequent complication of COVID-19. Among our patients treated with HDMTX, some of these developed AKI during SARS-CoV-2 infection. Therefore, we wondered whether our patients' kidney failure might have been triggered by their underlying SARS-CoV-2 positivity. Data were collected from the database at the Pediatric Oncology Unit of the Istituto Nazionale dei Tumori in Milan (Italy) regarding patients who matched the following selective criteria: (a) treatment with HDMTX during the pandemic period; (b) SARS-CoV-2 infection during the treatment; (c) development of AKI during HDMTX treatment and SARS-CoV-2 infection. From March 2020 to March 2022, a total of 23 patients were treated with HDMTX; 3 patients were treated with HDMTX during SARS-CoV-2 infection and all 3 developed AKI. Clinical manifestations associated with this virus are many, so we are not yet able to lower our guard and rule out this infection as a cause of clinical manifestations with any certainty.

[Relationship between MTHFR Gene Polymorphism(C677T) and Adverse Reactions of High-Dose Methotrexate in Pediatric Patients with Acute Lymphoblastic Leukemia].

To explore the effects of methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism on the adverse reactions of high-dose methotrexate (MTX) in pediatric patients with acute lymphoblastic leukemia (ALL). A total of 69 children with ALL admitted to the department of Pediatrics of Sun Yat-sen Memorial Hospital of Sun Yat-sen University from November 2018 to October 2020 were included in this study. The clinical data of the children were collected, leukocytes were isolated from their peripheral blood, and MTHFR genotyping was performed by digital fluorescence molecular hybridization techniques. The adverse reactions and plasma drug concentration of MTX were monitored during the chemotherapy. Moreover, the effect of MTHFR gene polymorphism on MTX adverse reactions and plasma drug concentration were analyzed. Among the middle and high risk children, compared with the wildtype group (CC genotype), patients with MTHFR C677T mutations (CT+TT genotypes) had a higher risk of leukopenia (OR=2.38), neutropenia (OR=2.2), anemia (OR=1.83) and hepatoxicity (OR=1.98). However, no significant difference was found in the MTX plasma concentration between the MTHFR C677T mutantion group and the wildtype group at different timepoints (24 h, 48 h and 72 h). Multivariate analysis revealed that the plasma concentration of MTX (48 h), clinical risk level of ALL and MTHFR C677T gene polymorphism were independent factors for the adverse reactions of high-dose MTX. The MTHFR C677T mutations may be associated with myelosuppression and hepatotoxicity in children with ALL after high-dose MTX treatment.

High-Dose Methotrexate: Nursing Considerations for Administration and Supportive Care.

High-dose methotrexate (HDMTX) is the backbone of many pediatric and adult oncology treatment protocols. It requires appropriate monitoring and supportive care because delayed elimination of MTX can lead to serious toxicities. No reviews specifically addressing nursing management regarding standard treatment protocols and delayed MTX elimination exist. This article provides an overview of HDMTX treatment and nursing considerations, including toxicities, components of supportive care management, and strategies to manage administration and delayed elimination of MTX. A review of published literature and guidelines was performed to evaluate nursing considerations for patients receiving HDMTX. Using existing and novel tools, nurses can closely monitor patients and provide supportive care to mitigate HDMTX toxicity. Early identification of delayed MTX elimination and subsequent treatment with glucarpidase, if appropriate, has been associated with shorter length of hospital stay and decreased incidence of grade 4 toxicities and mortality.

Clinical Outcomes and Treatment Patterns of Primary Central Nervous System Lymphoma: Multicenter Retrospective Analysis

Objectives: Primary central nervous system lymphoma (PCNSL) is a rare malignant disease with poor prognosis. Its low incidence leads to challenges in decision-making for treatment. As a matter of fact, there is still no consensus on the appropriate treatment modalities. In this context, the objective of this study is to investigate and comparatively assess the efficacies of several treatment modalities in the treatment of PCNSL. Methods: Thirty-four patients diagnosed with PCNSL at 5 different hematology centers between 2007 and 2021 were included in the study. Patients’ data from all five centers were collected retrospectively. Since ibrutinib is not approved for this indication in Turkey, consent for off-label use of ibrutinib is obtained from each patient. Ethics committee approval was obtained on June 9, 2021 with decision number 2021/18-05. Results: The median age of the patients was 59 (min.: 22, max.: 78) years. The male-to-female ratio was 1.26/1. Nineteen (55.9%) patients had Eastern Cooperative Oncology Group (ECOG) performance score of ?2. Fifteen (44.1%) patients had normal lactate dehydrogenase (LDH) levels and only 14.7% of the patients had B symptoms at the time of diagnosis. Magnetic resonance imaging (MRI) revealed a single mass lesion in 14 (41.2%) patients. As an induction therapy, methotrexate-based regimen was administered in 29 (85.3%) patients. Only 14 of the 34 patients received 4 or more cycles of high-dose methotrexate (MTX). About 32.4% of the patients received radiation therapy (RT) during follow-up as a part of induction therapy. Five patients received only RT due to poor performance status. Ibrutinib was administered in 5 patients for refractory disease. It was determined that four or more cycles of MTX treatment increased progression-free survival (PFS) (p=0.031) and overall survival (OS) (p=0.012). Moreover, RT improved PFS (p=0.023). Considering that the complete response achieved by induction therapy influences long-term survival, achievement of the best response to the treatment regimens administered in combination with new agents may prolong survival (PFS: p=0.01, OS: p=0.023). Conclusion: The findings of this study indicate that the initial response to treatment is crucial. Additionally, it was found that high-dose MTX treatment should be administered for 4 cycles or more in order to achieve the best results. Furthermore, it was determined that ibrutinib monotherapy was well-tolerated in our patients with relapsed/refractory disease, with excellent clinical benefits. In conclusion, a combination therapy consisting of high-dose MTX, ibrutinib, and rituximab appears to be a promising initial treatment approach in appropriate patients. Keywords: PCNSL, methotrexate, radiotherapy, ibrutinib

Target concentration achievement for efficacy and safety of patients with osteosarcoma treated with high-dose methotrexate based on individual pharmacokinetics: A retrospective study.

In the high-dose methotrexate (HD-MTX) treatment of patients with osteosarcoma, a dose-adjustment method using individual pharmacokinetic parameters (PK method) to optimize the concentration was developed in 2010. However, to the best of our knowledge, the clinical usefulness of the PK method has not been verified until now. In the present retrospective study, to assess the usefulness of the PK method, the achievement rate of an effective and safe concentration range was evaluated. A total of 43 patients with osteosarcoma who were administered HD-MTX therapy (43 first courses and 200 subsequent courses) were enrolled. The MTX dose in the first course was determined using a common method based on body surface area (BSA method); a total of 8-12 g/m2 was administered as an initial dose for 1 h and a maintenance dose for 5 h. In the subsequent courses, loading and maintenance doses were calculated by the PK method based on the serum MTX concentration profile of the previous course. The effective target concentration during 1-6 h after the start of MTX administration was 700-1,000 µmol/l, whereas the target safe MTX level was less than 10, 1 and 0.1 µmol/l at 24, 48 and 72 h, respectively. Notably, the rate of achieving the effective target concentration was significantly higher when using the PK method as compared to that when using the BSA method. The achievement rate of the safe target concentration at 24, 48 and 72 h when using the PK method was significantly higher. Additionally, the incidence of abnormal laboratory values of aspartate aminotransferase and alanine aminotransferase was significantly lower when using the PK method. Therefore, the PK method was suggested to be very useful in HD-MTX therapy for patients with osteosarcoma.

The metabolites of de novo NAD+ synthesis are a valuable predictor of acute kidney injury.

Acute kidney injury (AKI) is often iatrogenic and potentially preventable. Reduced renal nicotinamide adenine dinucleotide (NAD+) is reported to increase the susceptibility of AKI. The present study explored the predictive value of urinary de novo NAD+ synthetic metabolites for AKI using two independent cohorts. The expression of de novo NAD+ synthetic enzymes in human kidney was examined by immunohistochemistry and single-cell transcriptomes. Urine samples were collected from two independent cohorts: the methotrexate (MTX) cohort with high-dose MTX treatment for lymphoma (n=189) and the liver transplantation cohort with orthotopic liver transplantation (n=49). Urinary metabolomics study of NAD+ de novo synthesis was performed by liquid chromatography with mass spectrometry, screening for AKI predictive biomarkers. Nephroseq database and immunohistochemistry were used to analyze kidney de novo NAD+ synthetic enzymes expression in AKI-susceptible conditions. Human proximal tubule was the main structure in the kidney that expressed the necessary enzymes for NAD+ de novo synthesis. In the MTX cohort, the urinary quinolinic acid (QA)/3-hydroxyanthranilic acid (3-OH AA) ratio before chemotherapy was significantly lower in those who developed AKI after chemotherapy compared with those who did not. This finding was consistent in the liver transplantation cohort. The area under the receiver-operating characteristic curve (AUC) of urinary QA/3-OH AA for AKI prediction was 0.749 and 0.729 in two cohorts, respectively. 3-Hydroxyanthranilic acid dioxygenase (HAAO), the enzyme catalyzing QA synthesis from 3-OH AA, decreased in AKI-susceptible diabetic kidneys. The human proximal tubules were important source of NAD+ from the de novo pathway. Reduced urinary QA/3-OH AA ratio, which possibly suggested decreased HAAO activity, could be a potential AKI predictive biomarker.

CD79B Y196 mutation is a potent predictive marker for favorable response to R-MPV in primary central nervous system lymphoma.

Rituximab, high-dose methotrexate (HD-MTX), procarbazine and vincristine (R-MPV), has significantly prolonged the survival of patients with primary central nervous system lymphoma (PCNSL), but predictive factors for response to R-MPV have not yet been investigated. Herein, we investigated the correlation of MYD88 L265P and CD79B Y196 mutations, which are the most frequently found molecular alterations in PCNSL, with prognosis of patients with PCNSL treated with R-MPV. We investigated the long-term clinical course and status of MYD88 and CD79B genes in 85 patients with PCNSL treated with R-MPV or HD-MTX treatment, and the correlation of these genetic mutations with prognosis. R-MPV achieved an excellent tumor control rate (61.6% and 69.9% of 5-year progression-free and overall survival rates, respectively). While MYD88 L265P mutation had no significant effect on survival, patients with CD79B Y196 mutations exhibited prolonged survival (p < 0.05). However, the association of CD79B Y196 mutation with a better prognosis was not observed in the HD-MTX cohort, which indicated that CD79B Y196 mutation was a predictive marker for a favorable response to R-MPV. Furthermore, we established an all-in-one rapid genotyping system for these genetic mutations. In conclusion, CD79B Y196 mutation is a potent predictive marker for favorable response to R-MPV in PCNSL. The rapid identification of MYD88 L265P and CD79B Y196 mutations can be helpful not only for the accurate molecular diagnosis of PCNSL but also for the prediction of response to R-MPV.

Association between high-dose methotrexate-induced toxicity and polymorphisms within methotrexate pathway genes in acute lymphoblastic leukemia.

Methotrexate (MTX) is a folic acid antagonist, the mechanism of action is to inhibit DNA synthesis, repair and cell proliferation by decreasing the activities of several folate-dependent enzymes. It is widely used as a chemotherapy drug for children and adults with malignant tumors. High-dose methotrexate (HD-MTX) is an effective treatment for extramedullary infiltration and systemic consolidation in children with acute lymphoblastic leukemia (ALL). However, significant toxicity results in most patients treated with HD-MTX, which limits its use. HD-MTX-induced toxicity is heterogeneous, and this heterogeneity may be related to gene polymorphisms in related enzymes of the MTX intracellular metabolic pathway. To gain a deeper understanding of the differences in toxicity induced by HD-MTX in individuals, the present review examines the correlation between HD-MTX-induced toxicity and the gene polymorphisms of related enzymes in the MTX metabolic pathway in ALL. In this review, we conclude that only the association of SLCO1B1 and ARID5B gene polymorphisms with plasma levels of MTX and MTX-related toxicity is clearly described. These results suggest that SLCO1B1 and ARID5B gene polymorphisms should be evaluated before HD-MTX treatment. In addition, considering factors such as age and race, the other exact predictor of MTX induced toxicity in ALL needs to be further determined.

NCMP-13. TOLERANCE OF HIGH-DOSE METHOTREXATE TREATMENT OF PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA (PCNSL) PATIENTS WITH RENAL IMPAIRMENT, CASE SERIES AND REVIEW OF LITERATURE

Abstract PCNSL in immune competent patients is a rare extra-nodal non-Hodgkin lymphoma that accounts for 3–4% of newly diagnosed CNS tumors. Treatment consists of high-dose methotrexate (HD-MTX) based polychemotherapy regimen with or without brain radiation. There are few reported cases supporting the use of HD-MTX as a treatment option in such patients with impaired renal function. The objective of this study was to analyze outcomes and tolerance of HD-MTX based chemotherapy regimen (HD-MTX, rituximab and temozolomide, MRT) in patients with PCNSL and renal impairment. We present five patients with median age 63 (range 40 – 67) at diagnosis, with varying degrees of renal impairments, were all treated with and tolerated well of MRT. They are all alive and have been on observation. Cases 2 &amp; 3 had a one functioning kidney and achieved complete responses (CR) without toxicities. Case 1, with history of grade 3 renal insufficiency during his initial HD-MTX and received carboxypeptidase G2 rescue, tolerated re-treatment with MRT at PCNSL recurrence and achieved a partial response (PR) that has been stable for 44 months. Case 4, who had a cadaver-transplanted kidney, was able to get a CR after 8 treatment with MRT. Case 5, with grade 3 chronic kidney disease from type II diabetes mellitus, achieved CR with MRT with slowing down of his MTX clearance. Literature review for reports with PCNSL and renal impairment treated with HD-MTX through March 31, 2022 identified eight cases and their responses and adverse effects summarized. Due to the low number of published cases and limitation of a retrospective analysis, it is impossible to draw a conclusion on the impact of impaired renal function on the tolerance of HD-MTX treatment of PCNSL. However, our findings indicate that a subset of the patients may still benefit from treatment with HD-MTX based chemotherapy.

Analysis of Key Factors Associated with Response to Salvage High-Dose Methotrexate Rechallenge in Primary Central Nervous System Lymphoma with First Relapse

Background: Primary central nervous system lymphoma (PCNSL) is a rare extranodal non-Hodgkin’s lymphoma that occurs in the central nervous system. Although sensitive to chemotherapy, 35–60% of PCNSL patients still relapse within 2 years after the initial treatment. High-dose methotrexate (HD-MTX) rechallenge is generally used in recurrent PCNSL, especially for patients who have achieved a response after initial methotrexate (MTX) treatment. However, the overall remission rate (ORR) of HD-MTX rechallenge is about 70–80%. Additionally, the side effects of HD-MTX treatment endanger the health of patients and affect their quality of life. Methods: This is a retrospective study of patients with first relapse PCNSL at Huashan Hospital, Fudan University between January 2000 and November 2020. By comparing the clinical characteristics and radiological manifestations of first relapsed PCNSL patients with remission and non-remission after receiving HD-MTX rechallenge, we screened out the key factors associated with HD-MTX rechallenge treatment response, to provide some help for the selection of salvage treatment strategies for patients with recurrent PCNSL. Additionally, patients with remission after HD-MTX rechallenge were followed up to identify the factors related to progression-free survival of the second time (PFS2) (time from the first relapse to second relapse/last follow-up). The Kruskal–Wallis and Pearson chi-square tests were performed to examine the univariate association. Further, multivariable logistic regression analysis was used to study the simultaneous effect of different variables. Results: A total of 207 patients were enrolled in the study based on the inclusion criteria, including 114 patients in the remission group (RG) and 81 patients in the non-remission group (nRG), and 12 patients were judged as having a stable disease. In Kruskal–Wallis and Pearson chi-square tests, progression-free survival rates for first time (PFS1) and whether the initial treatment was combined with consolidated whole brain radiotherapy (WBRT) were related to the response to HD-MTX rechallenge treatment, which was further validated in regression analysis. Further, after univariate analysis and regression analysis, KPS was related to PFS2. Conclusions: For PCNSL patients in their first relapse, HD-MTX rechallenge may be an effective salvage treatment. PFS1 and whether initial treatment was combined with consolidation WBRT were associated with HD-MTX rechallenge treatment response. In addition, patients with higher KPS at the time of the first relapse had a longer PFS2 after HD-MTX rechallenge treatment.

Leucovorin (folinic acid) rescue for high-dose methotrexate: A review.

High-dose methotrexate (HDMTX) is active against various malignancies; it possesses serious toxicities and is associated with patient characteristics, dosage regimens, comedications, and physiological status. There are many strategies to overcome HDMTX-induced toxicities, such as hydration, alkalization, leucovorin rescue, and haemodialysis. Leucovorin rescue is a cornerstone for toxicity prevention in HDMTX treatment. However, the leucovorin dose adjustment and the existence of leucovorin overrescue are still controversial. At present, various methods for calculating leucovorin doses in different tumour types have been proposed, including empirical calculations based on MTX plasma concentration, the Bleyer nomogram, and other methods. Nonetheless, leucovorin rescue protocols differ greatly across tumour types and medical institutions. Further studies are needed to investigate the optimal dosage regimen for leucovorin rescue in various tumours using HDMTX.