Reduced dose folinic acid rescue after rapid high-dose methotrexate clearance is not associated with increased toxicity in a pediatric cohort

Effects of gene polymorphisms on delayed MTX clearance, toxicity, and metabolomic changes after HD-MTX treatment in children with acute lymphoblastic leukemia

This study aims to assess the role of methotrexate-related gene polymorphisms in children with acute lymphoblastic leukemia (ALL) during high-dose methotrexate (HD-MTX) therapy and to explore their effects on serum metabolites before and after HD-MTX treatment. The MTHFR 677C>T, MTHFR 1298A>C, ABCB1 3435C>T, and GSTP1 313A>G genotypes of 189 children with ALL who received chemotherapy with the CCCG-ALL-2020 regimen from January 2020 to April 2023 were analyzed, and toxic effects were reported according to the Common Terminology Criteria for Adverse Events (CTCAE, version 5.0). Fasting peripheral blood serum samples were collected from 27 children before and after HD-MTX treatment, and plasma metabolites were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS). The results of univariate and multivariate analyses showed that MTHFR 677C>T and ABCB1 3435 C>T gene polymorphisms were associated with the delayed MTX clearance (P < 0.05) and lower platelet count after treatment in children with MTHFR 677 mutation compared with wild-type ones (P < 0.05), and pure mutations in ABCB1 3435 were associated with higher serum creatinine levels (P < 0.05). No significant association was identified between MTHFR 677C>T, MTHFR 1298A>C, ABCB1 3435 C>T, and GSTP1 313A>G genes and hepatotoxicity or nephrotoxicity (P > 0.05). However, the serum metabolomic analysis indicated that the presence of the MTHFR 677C > T gene polymorphism could potentially contribute to delayed MTX clearance by influencing L-phenylalanine metabolism, leading to the occurrence of related toxic side effects.

CONCLUSION

MTHFR 677C>T and ABCB1 3435 C>T predicted the risk of delayed MTX clearance during HD-MTX treatment in children with ALL. Serum L-phenylalanine levels were significantly elevated after HD-MTX treatment in children with the MTHFR 677C>T mutation gene.

TRIAL REGISTRATION

This study was registered at the Chinese Clinical Trial Registry (registration number: ChiCTR2000035264; registration: 2020/08/05; https://www.chictr.org.cn/ ).

WHAT IS KNOWN

• MTX-related genes play an important role in MTX pharmacokinetics and toxicity, but results from different studies are inconsistent and the mechanisms involved are not clear.

WHAT IS NEW

• Characteristics, prognosis, polymorphisms of MTX-related genes, and metabolite changes were comprehensively evaluated in children treated with HD-MTX chemotherapy. • Analysis revealed that both heterozygous and pure mutations in MTHFR 677C>T resulted in a significantly increased risk of delayed MTX clearance, and that L-phenylalanine has the potential to serve as a predictive marker for the metabolic effects of the MTHFR 677C>T polymorphism.

Reagentless impedimetric immunosensor for monitoring of methotrexate in human blood serum using multiwalled carbon nanotube@polypyrrole/polytyramine film electrode

Ensuring effective monitoring of methotrexate (MTX) levels in the bloodstream of cancer patients undergoing high-dose methotrexate chemotherapy is crucial to prevent potentially harmful side effects. However, the absence of portable analytical devices suitable for point-of-care bedside monitoring has presented a significant obstacle to achieving real-time MTX monitoring. In this study, we developed an impedimetric immunosensor that doesn't require reagents for measuring MTX levels in undiluted human blood serum. This reagentless approach simplifies the assay process, enabling rapid and straightforward MTX quantification. The immunosensor transducer was fabricated by electrodepositing conductive network of porous multiwalled carbon nanotube@polypyrrole/polytyramine on screen-printed gold microchip electrode (SP-Au/MWCNT70@PPy-PTA). Polyclonal anti-MTX antibodies were immobilized on the film, acting as the immunorecognition element. Non-specific binding was prevented by blocking the transducer interface with denatured bovine serum albumin (dBSA) fibrils, resulting in SP-Au/MWCNT70@PPy-PTA/anti-MTXAb|dBSA film electrode. When MTX binds to the SP-Au/MWCNT70@PPy-PTA/anti-MTXAb|dBSA interface, the film conductance and electron transfer resistance changes. This conductivity attenuation allows for electrochemical impedimetric signal transduction without a redox-probe solution. The electrochemical impedance spectroscopy (EIS) results showed increased charge transfer resistance and phase angle as MTX concentrations increased. The SP-Au/MWCNT70@PPy-PTA/anti-MTXAb|dBSA demonstrated high sensitivity, with a linear response from 0.02 to 20.0 μM and a detection limit of 1.93 nM. The detection limit was 50 times lower than the intended safe level of MTX in human serum. The immunosensor exhibited minimal cross-reactivity with endogenous MTX analogs and serum proteins. The SP-Au/MWCNT70@PPy-PTA/anti-MTXAb|dBSA immunosensor presents a simple and rapid method for therapeutic drug monitoring compared to traditional immunoassay systems.

The effect of the plasma methotrexate concentration during high-dose methotrexate therapy in childhood acute lymphoblastic leukemia

Two hundred and thirty-one acute lymphoblastic leukemia (ALL) children with 1376 high-dose methotrexate (HD-MTX) courses (3-5 g/m2) were enrolled to analyze the influence of the plasma MTX concentration (CMTX) in ALL. The 24-h target peak CMTX (C24h) was set at 33 μmol/l for low-risk (LR) and 65 μmol/l for intermediate/high-risk (IR/HR) groups. The median C24h was 42.0 μmol/l and 69.7 μmol/l for LR and IR/HR groups, respectively. MTX excretion delay was observed in 14.6% of courses, which was more frequent in IR/HR groups (56.9% vs. LR group 40.2%, p = .014) and T-ALL patients (82.6% vs. B-ALL 47.1%, p = .001). MTX-related toxicities were more common in courses with MTX excretion delay. However, survival between the patients who failed to reach the target C24h or not, with or without MTX excretion delay, was comparable. These findings suggest that, owing to the effectiveness of risk stratification chemotherapy, CMTX does not exert an independent influence on the prognosis of childhood ALL.

The use of glucarpidase as a rescue therapy for high dose methotrexate toxicity - a review of pharmacological and clinical data

INTRODUCTION

This review aims to summarize recent data on the pharmacodynamic, pharmacokinetic, and safety of glucarpidase. This is an enzymatic agent that catalyzes the conversion of methotrexate (MTX) into inactive metabolites. Glucarpidase is used to manage high-dose MTX (HDMTX) toxic plasma concentration, especially in patients with impaired renal function.

AREAS COVERED

In this review, studies on glucarpidase clinical efficacy as a therapeutic option for patients suffering from MTX kidney toxicity were presented. Pharmacodynamic and pharmacokinetic properties of glucarpidase were included. Moreover, potential interactions and safety issues were discussed.

EXPERT OPINION

The use of glucarpidase is an effective therapeutic strategy in both adults and children treated with high doses of MTX for various types of cancer who have developed acute renal failure. Glucarpidase causes MTX to be converted to nontoxic metabolites and accelerates the time for its complete elimination. After administration of glucarpidase, it is possible to resume HDMTX.

Overview of Methotrexate Toxicity: A Comprehensive Literature Review

Methotrexate (MTX) is significantly more effective than and has a considerable advantage over placebo in patients with severe and persistent rheumatoid arthritis (RA). The drug is used to treat a variety of malignant disorders (leukemia and cancer of the lung, breast, and uterus) and ectopic pregnancy. As its side effects are outweighed by its effectiveness, MTX is a first-line antirheumatic drug in many countries. MTX is found in extracellular compartments, such as the synovium, as well as other organs, such as the kidney and liver. To improve treatment, increase adherence, and decrease mortality in MTX therapy, it is essential to reduce its toxicity and understand its side effects. Therefore, this comprehensive review was conducted to assist physicians and researchers in better understanding the toxicity of MTX and how to deal with this toxicity. MTX is eliminated via the kidneys, which are capable of excretion and reabsorption within the renal tubules. Although higher doses of MTX (known as high-dose MTX (HD-MTX), defined as doses of 500 mg/m² or greater) are often more beneficial, they can produce toxicity and side effects such as bone marrow suppression, pulmonary toxicity, nephrotoxicity, hematologic toxicity, and an increased risk of infections. Treatment of severe MTX toxicity has three main goals: clearance of MTX from the bloodstream, folinic acid therapy, and organ treatment. Leucovorin is highly beneficial in preventing myelosuppression, gastric toxicity, and neurotoxic effects after HD-MTX therapy. The preferred antidote for MTX poisoning is folinic acid. Glucarpidase has been licensed for the treatment of high plasma MTX levels of >1 μmol/L in patients with compromised renal function who have delayed MTX elimination. In patients with renal deficiency, a lower initial dose is considered with an estimated glomerular filtration rate (eGFR) between 30 and 59 mL/minute. These patients need to be monitored, and a more gradual dosage increase and a lower weekly maximum should be considered regarding their general health situation. MTX is contraindicated in patients with RA if the eGFR is <30 mL/minute.

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.

Antioxidant nutrients can increase high-dose Methotrexate efficacy in 4T1 breast tumor Model: An experimental study on Vitamin E Succinate and Methyl-selenic acid

BACKGROUND

We aimed to evaluate the anti-cancer and immune system enhancing properties of Vitamin E succinate (VES) and methylselenic acid (MSA) administration on 4T1 breast tumor model under high-dose methotrexate (HDMTX) therapy and folinic acid (FA) rescue.

METHODS

Thirty six 4T1 mammary carcinoma bearing mice were randomly divided into six groups: control (untreated; n = 6), treatment-1 (T1 group; HDMTX; n = 6), T2 (T1 + FA; n = 6), T3 (T2 + MSA; n = 6), T4 (T2 + VES; n = 6) and T5 (T3 + VES; n = 6). On day 21 of the study, all surviving mice were sacrificed and primary tumors and peripheral tissues were examined for histological and gene expression assays. The expression of GATA Binding Protein-3 (GATA3), forkhead box-P3 (FOXP3), T-bet and Retinoic acid receptor-related orphan receptor γt (RORγt) were evaluated in tumors and spleens. Also, vascular endothelial growth factor-A (VEGF-A) and UL16-Binding Protein 1 (ULBP-1) expression were evaluated in tumors.

RESULTS

The control, T4 and T5 groups were able to complete the entire 21-day study period. Also, significant tumor shrinkage was occurred in T4 group (P < 0.05). Suppression of splenic FOXP3 and GATA3 were observed in the mice receiving T4 and T5 regimens. Also, induction of tumoral FOXP3 and GATA3 were achieved in the T4 and T5 groups, respectively (P < 0.05). No metastasis occurred in T4 receiving group; while, lung and liver metastasis were observed in T5 group.

CONCLUSION

In this study, high and fixed dose of MTX was used. Further studies are needed to optimize MTX dose along with FA, VES and MSA.