Use of mycophenolate mofetil in patients with pediatric and adult primary nephrotic syndrome: information from a Japanese hospital claims database

Abstract

Background Current treatment for frequently relapsing, steroid-dependent, or steroid-resistant nephrotic syndrome focuses on immunosuppressive therapies. Although the clinical guideline suggests the use of mycophenolate mofetil (MMF), limited information is available on patients with primary nephrotic syndrome who receive off-label treatment with MMF in Japan. Method The dose, treatment duration, previous treatment, and characteristics of primary nephrotic syndrome patients receiving MMF were investigated using data from a Japanese hospital claims database (April 2008–September 2021). Results Data on 424 primary nephrotic syndrome patients receiving MMF (146 patients < 18 years old; 278 patients ≥ 18 years old) were captured. The most common initial daily doses of MMF capsules (% of patients < 18 and ≥ 18 years old) were 1000 mg (31.9%, 36.8%), 1500 mg (16.0%, 23.8%), and 500 mg (23.6%, 17.3%), and the most common maximum daily doses were 1000 mg (43.8%, 32.9%), 1500 mg (23.6%, 28.9%), and 2000 mg (6.3%, 16.2%). Most patients (97.9%, 99.3%) were treated with a daily dose of 2000 mg or less. Among patients < 18 years old, the younger the patient, the lower the dose. MMF was used for more than 1 year in 30.8% of patients < 18 years old and in 28.8% of patients ≥ 18 years old. Conclusions Our study suggested that off-label use of MMF for primary nephrotic syndrome has increased since 2012 in Japan. The dose of MMF used in patients with primary nephrotic syndrome was generally within the approved dose range for lupus nephritis and transplant-related diseases in Japan.

Body Surface Area-Based Dosing of Mycophenolate Mofetil in Pediatric Hematopoietic Stem Cell Transplant Recipients: A Prospective Population Pharmacokinetic Study

“…Using the validated final PPK model, a Monte Carlo simulation involving 1000 iterations was performed to generate PK of MPA under various scenarios including different BSAs (0.5 m 2 , 1.0 m 2 , and 1.5 m 2 ) and different dosages of oral administration of MMF (400 mg/m 2 , 600 mg/m 2 , and 900 mg/m 2 given twice daily). Different doses were derived from the actual dose used at practice based on drug label: 400 mg/m 2 , pediatric dose for kidney transplantation [40]; 600 mg/m 2 , pediatric dose for kidney, heart, and liver transplantation; 900 mg/m 2 , pediatric maximum dose recommended for heart and liver transplantation [41]. Based on the simulation results, the recommended pediatric dose for oral MMF was determined when the AUC 0-12 were within the therapeutic target range of 30-60 mg•h/L.…”