Kidney Week

Abstract: FR-PO0824

Beyond the Dose: Establishing Optimal Mycophenolate Therapeutic Drug Monitoring Targets for Nephrotic Syndrome in Children

Session Information

• Glomerular Diseases: Practice and New Concepts Shaping Modern Care
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Riedl Khursigara, Magdalena, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Magdalena Riedl Khursigara, MD, PhD

• Robinson, Cal, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Cal Robinson, MBChB, PhD, FASN

• Chung, Erin, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Erin Chung, RPh

• Seto, Winnie, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Winnie Seto, MD, MS, PharmD, RPh

• Hamdan, Diana, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Diana Hamdan, MSc

• Hong, Junhee, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Junhee Hong

• Bruno, Valentina, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Valentina Bruno, MD, MS, MSc

• Aman, Nowrin F., The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Nowrin F. Aman, MBBS, MSc

• Banh, Tonny Hue Minh, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Tonny Hue Minh Banh

• Brooke, Josefina A., The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Josefina A. Brooke, RN

• Dhillon, Vaneet, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Vaneet Dhillon, NP, RN

• Garner, Mackenzie Alexander, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Mackenzie Alexander Garner

• Licht, Christoph, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Christoph Licht, MD, FASN

• McKay, Ashlene Maree, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Ashlene Maree McKay, MD

• Noone, Damien Gerard, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Damien Gerard Noone, MD, MSc

• Pearl, Rachel Jane, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Rachel Jane Pearl, MD

• Radhakrishnan, Seetha, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Seetha Radhakrishnan, MD

• Rasool, Keisha, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Keisha Rasool, RN

• Selvathesan, Nithiakishna, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Nithiakishna Selvathesan, MD, MBChB

• Vanos Hosick, Kristen, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Kristen Vanos Hosick, RN

• Vasilevska-Ristovska, Jovanka, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Jovanka Vasilevska-Ristovska, MD

• Parekh, Rulan S., The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Rulan S. Parekh, MD, MS, FASN

• Tjon, James Anthony, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

James Anthony Tjon, PharmD

• Teoh, Chia Wei, The Hospital for Sick Children Department of Paediatrics, Toronto, Ontario, Canada

Chia Wei Teoh, MBChB, MSc

Background

Mycophenolic acid (MPA) is a commonly used steroid-sparing immunosuppressant in nephrotic syndrome. Therapeutic drug monitoring (TDM) based on trough concentrations or area under the concentration-time curve (AUC) target ranges is not well established for clinical outcomes in nephrotic syndrome. We aimed to identify the optimal TDM targets for MPA in children with nephrotic syndrome.

Methods

We performed a retrospective analysis of children with nephrotic syndrome (aged 1–18 years) treated with mycophenolate mofetil (MMF) or enteric-coated mycophenolate sodium, with AUC measured between 2019-2025. Exposures included MPA-AUC_0-12h, MPA trough concentrations, and MMF equivalent dose per body surface area or weight. Clinical outcomes included relapse rate, time-to-relapse and adverse effects. We determined an optimal MPA-AUC_0-12h range, based on time-to-relapse and adverse effects. Poisson regression models with natural splines and Receiver Operating Characteristic curve were used to evaluate the association between MPA-AUC_0-12h and relapse rate, as well as adverse effects.

Results

A total of 131 MPA-AUC_0-12h measurements were performed among 67 children with frequent-relapsing nephrotic syndrome. Most children (87%) received MPA after rituximab. MPA-AUC_0-12h, but not trough concentration or MMF equivalent dose by weight or surface area, was strongly correlated with relapse rate and time-to-relapse. A 10mg*hr/L increase of MPA-AUC_0-12h was associated with fewer relapses (incidence rate ratio [IRR] 0.70, 95%CI 0.59-0.82) and longer time-to-relapse (hazard ratio 0.77, 95%CI 0.64-0.92). For relapse rate, the best model fit was achieved using two knots at MPA-AUC_0-12h of 41 and 57mg*hr/L. Higher MPA-AUC_0-12h, especially ≥ 60mg*hr/L, was associated with increased risk of neutropenia (odds ratio 1.18 per 10mg*hr/L increase, 95%CI 1.02-1.36).

Conclusion

Our findings suggest an initial target MPA-AUC_0-12h between 40-60mg*h/L provided an optimal balance between relapse prevention and adverse effects. Further increases of MPA-AUC_0-12h above 60mg*h/L may provide further relapse risk reduction, but should be carefully weighed against neutropenia risk.

Funding

• Government Support – Non-U.S.