A Study of the Pharmacokinetic Comparison between the Generic and Original Form of Mycophenolate Mofetil Among Thai Renal Transplant Patients

Background: Mycophenolic acid (MPA) is one of the main immunosuppressive regimens used after kidney transplantation (KT). The less expensive, generic form of mycophenolate mofetil (MMF) (Immucept^®) is recently available in Thailand. Comparisons of the pharmacokinetic profiles between the original and generic forms of MMF among post-KT patients are limited. Methods: This prospective cohort study recruited KT patients receiving stable doses of MMF 1000 mg daily along with tacrolimus and steroids. All participants were prescribed CellCept^® 500 mg every 12 hours for at least 2 weeks before measuring the MPA area under the curve from 0 to 12 hours (AUC_0-12). CellCept^® was switched to Immucept^® 500 mg every 12 hours for 2 weeks and MPA AUC_0-12 was remeasured. Results: Twenty patients with a median follow-up time of 35.4 (11.13–198.83) months were enrolled. Mean MPA AUC_0-12 of Immucept^® was higher than CellCept^® without statistical significance (48.27 ± 2.31 μg⋅hr/mL vs 42.19±15.20 μg⋅hr/mL; P value =.59). No difference was revealed regarding the minimum measured concentration, maximum measured concentration, and time point with maximum concentration between both drugs. While on CellCept^®, 5 patients (25%) had an MPA AUC_0-12 < 30.0 μg⋅hr/mL, but 3 patients (15%) had MPA AUC_0-12 < 30.0 μg⋅hr/mL when receiving Immucept^®. However, 3 (15%) and 6 (30%) patients had MPA AUC_0-12 > 60.0 μg⋅hr./mL when treated with CellCept^® and Immucept^®, respectively. Conclusion: Generic MMF exhibited a comparable pharmacodynamic profile as the original formulation. MPA AUC_0-12 was more than 30.0 μg⋅hr/mL among most patients receiving MMF 1000 mg/day.