The AAPS Journal

, 21:6 | Cite as

Overlooked Issues on Pharmacokinetics Data Interpretation of Protein Drugs—a Case Example of Erythropoietin

  • Guohua AnEmail author
  • Robert L. Schmidt
  • Donald M. Mock
  • Peter Veng-Pedersen
  • John A. Widness
Brief/Technical Note

Recombinant human erythropoietin (rhEPO) has been used for over 30 years as a major therapeutic agent for treatment of anemia caused by chronic kidney disease and chemotherapy. During this period, a great deal has been learned about rhEPO and its physiological role in the regulation of erythropoiesis (1). Nevertheless, several issues remain to be resolved in the rhEPO pharmacokinetics arena due to the challenges of unifying different assays and different EPO standards. In this communication, we report two frequently overlooked issues on pharmacokinetics data interpretation of rhEPO and offer solutions to ensure reliable estimation of the pharmacokinetics parameters. To the best of our knowledge, there have been no reports on these important issues.


Unlike small-molecule compounds whose amounts are expressed in grams or moles, EPO amounts are expressed in units (U), which is defined based on EPO’s biological activity determined by in vivo bioassays (2)....


erythropoietin overlooked issues pharmacokinetic data interpretation protein drugs 


Funding Information

This work was supported in part by National Institutes of Health (NIH) US Public Health Service Program Project Grant P01 HL046925 and the National Center For Advancing Translational Sciences of the National Institutes of Health under Award Number U54TR001356.

Compliance with Ethical Standards


The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.


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Copyright information

© American Association of Pharmaceutical Scientists 2018

Authors and Affiliations

  • Guohua An
    • 1
    Email author
  • Robert L. Schmidt
    • 2
  • Donald M. Mock
    • 3
  • Peter Veng-Pedersen
    • 1
  • John A. Widness
    • 2
  1. 1.Division of Pharmaceutics and Translational Therapeutics, College of PharmacyUniversity of IowaIowa CityUSA
  2. 2.Department of Pediatrics, Roy J. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityUSA
  3. 3.Departments of Biochemistry and Molecular Biology and PediatricsUniversity of Arkansas for Medical SciencesLittle RockUSA

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