Glucarpidase for Treatment of High-Dose Methotrexate Toxicity.

High-dose methotrexate (MTX) results in high rates of acute kidney injury (AKI), neutropenia, and hepatotoxicity. Glucarpidase is a recombinant enzyme that cleaves MTX, but clinical data supporting its use are scarce. We examined the association between glucarpidase administration and outcomes in adults with MTX-AKI from 28 cancer centers across the U.S using a sequential target trial emulation framework. The primary end point was kidney recovery at hospital discharge, defined as survival to discharge with serum creatinine <1.5-fold baseline and without dialysis-dependence. Key secondary end points were time-to-kidney recovery, neutropenia and transaminitis on day 7, and time-to-death. Using multivariable logistic and Cox regression models, we compared outcomes in patients who received glucarpidase within 4 days following MTX initiation with those in patients who did not. Among 708 patients with MTX-AKI, 209 (29.5%) received glucarpidase. Overall, 183 (25.8%) had a primary end point event. Glucarpidase receipt was associated with a 2.70-fold higher adjusted odds of kidney recovery (95% CI, 1.69-4.31) compared to no glucarpidase receipt. Patients treated with glucarpidase also had faster time-to-kidney recovery (adjusted hazard ratio [aHR], 1.88, 95% CI, 1.18-3.33) and lower risks of grade ≥2 neutropenia (adjusted odds ratio [aOR], 0.50, 95% CI, 0.28-0.91) and grade ≥2 transaminitis (aOR, 0.50, 95% CI, 0.28-0.91) on day 7. There was no difference in time-to-death (aHR, 0.76; 95 CI, 0.49-1.18). These data suggest glucarpidase may improve both renal and extrarenal outcomes in patients with MTX-AKI.