Rechallenge With High-Dose Methotrexate After Treatment With Glucarpidase in Adult Patients With Lymphoma.

PURPOSE: Limited evidence exists regarding methotrexate (MTX) resumption after patients with lymphoma receive glucarpidase for toxic MTX levels and acute kidney injury (AKI). METHODS: This retrospective review included adults with lymphoma treated with glucarpidase after MTX at Mayo Clinic between January 31, 2020, and October 10, 2022. Descriptive statistics summarize patient characteristics and clinical outcomes. RESULTS: Of 11 patients treated with glucarpidase after MTX, seven (64%) were rechallenged with MTX. Indications for MTX rechallenge included confirmed CNS disease (n = 6, 86%) and intravascular lymphoma (n = 1, 14%). Compared with the nonrechallenged subgroup, before receiving MTX that required glucarpidase rescue, the rechallenged patients had lower median pretreatment serum creatinine (Scr; 0.7 v 1.2 mg/dL), and none had AKI with previous MTX doses, n = 0 (0%) versus n = 2 (50%). During the MTX dose requiring glucarpidase rescue, the rechallenged group had lower median peak Scr (1.26 v 3.32 mg/dL) and lower incidence of AKI stage III (n = 1 [14%] v n = 3 [75%]), and none of the rechallenged patients required renal replacement therapy (RRT; n = 0 [0%] v n = 1 [25%]). At the first rechallenge after glucarpidase administration, the median MTX dose reduction was 56% (range, 46%-75%), and the lowest used dose when prescribed according to each treatment protocol schedule was 1.5 g/m2. Two (29%) patients experienced AKI (n = 1 stage I, n = 1 stage II) after MTX rechallenge. Zero patients required RRT, and zero required another glucarpidase administration. Six (86%) patients completed all recommended MTX doses. CONCLUSION: In selected adults with lymphoma who required glucarpidase for toxic MTX levels after administration of high-dose MTX, resumption of MTX therapy at lower doses is safe. Patients selected for MTX resumption had experienced less severe AKI during the previous cycle compared with those not selected for MTX resumption.

Development and validation of a model to predict acute kidney injury following high-dose methotrexate in patients with lymphoma.

STUDY OBJECTIVE: To develop and validate a model for predicting acute kidney injury (AKI) after high-dose methotrexate (HDMTX) exposure. DESIGN: Retrospective analysis. SETTING: Multisite integrated health system throughout Minnesota and Wisconsin. PATIENTS: Adult patients with lymphoma who received HDMTX as a 4-h infusion. MEASUREMENTS AND MAIN RESULTS: LASSO methodology was used to identify factors available at the outset of therapy that predicted incident AKI within 7 days following HDMTX. The model was then validated in an independent cohort. The incidence of AKI within 7 days following HDMTX was 21.6% (95% confidence interval (CI) 18.4%-24.8%) in the derivation cohort (435 unique patients who received a total of 1642 doses of HDMTX) and 15.6% (95% CI 5.3%-24.8%) in the validation cohort (55 unique patients who received a total of 247 doses of HDMTX). Factors significantly associated with AKI after HDMTX in the multivariable model included age ≥ 55 years, male sex, and lower HDMTX dose number. Other factors that were not found to be significantly associated with AKI on multivariable analysis, but were included in the final model, were body surface area, Charlson Comorbidity Index, and estimated glomerular filtration rate. The c-statistic of the model was 0.72 (95% CI 0.69-0.75) in the derivation cohort and 0.72 (95% CI 0.60-0.84) in the validation cohort. CONCLUSION: This model utilizing identified sociodemographic and clinical factors is predictive of AKI following HDMTX administration in adult patients with lymphoma.

High-Dose Methotrexate in Patients With Lymphoma: Predictors of a Complicated Course.

PURPOSE: High-dose methotrexate (HDMTX; > 500 mg/m2) is an important component of lymphoma therapy. Serum MTX monitoring at 48 hours is the standard approach to identify those at increased risk of developing MTX toxicity. Our aim was to characterize the incidence of complications and their association with MTX levels. METHODS: A retrospective review of our institutional electronic medical record was conducted to identify patients with lymphoma who received HDMTX between January 1, 2002, and December 31, 2018. We characterized the incidence of acute kidney injury (AKI), intensive care unit (ICU) admission, length of hospital stay (LOS), and 30-day mortality across 48-hour MTX levels. To establish an association between 48-hour MTX levels and the complications listed, we performed chi-square analysis for dichotomous variables and Kruskal-Wallis for nonparametric data. Receiver operator characteristic curve analysis was performed to identify the MTX level where AKI grade ≥ 2 was more likely. Multivariate logistic regression analysis was performed to identify risk factors for this MTX level. RESULTS: We identified 642 patients with 2,804 cycles of HDMTX. The incidence of AKI was 19.1% with AKI grade ≥ 2 making up 21% of cases. Rates of AKI, ICU admission, and 30-day mortality are associated with elevated 48-hour MTX levels. There was a significant increase in median LOS with elevated MTX levels (P < .001). Receiver operator characteristic curve analysis for AKI grade ≥ 2 demonstrated a 48-hour MTX level threshold of 1.28 µmol/L. Multivariate logistic regression analysis revealed age, male sex, elevated body surface area, higher MTX dose, monotherapy, and first cycle as independent factors. CONCLUSION: Elevated MTX levels are associated with a significant increased rate of AKI, ICU admission, prolonged LOS, and 30-day mortality. Elevated 48-hour MTX levels, particularly > 1.28 µmol/L, should alert clinicians for complications and to initiate measures to reduce MTX levels.