U.S. flag An official website of the United States government
  1. Home
  2. For Industry
  3. FDA User Fee Programs
  4. Generic Drug User Fee Amendments
  5. FY2016 Regulatory Science Report: Postmarket: Patient Substitution Studies
  1. Generic Drug User Fee Amendments

FY2016 Regulatory Science Report: Postmarket: Patient Substitution Studies

This section contains only new information from FY2016. For background scientific information and outcomes from previous years on this research topic, please refer to the FY15 Regulatory Science Research Report on Postmarket: Patient Substitution Studies.

ORS staff facilitating research in this area

  • Wenlei Jiang, Sarah Dutcher, Nan Zheng, Hyewon Kim, Andrew Babiskin, Lanyan Fang, Oluwamurewa Oguntimein, Larissa Lapteva, Kimberly Witzmann, Xia Pu and other ORS staff members

Projects and Collaborators

  • Pharmacokinetic studies of anti-epileptic drugs (I)
    • Site PI: Jim Polli and Tricia Ting
    • Contract #: HHSF223201010244A
  • Pharmacokinetic studies of anti-epileptic drugs (II)
    • Site PI: Michael Privetera and Michel Berg
    • Contract #: HHSF223201110112A
  • Characterization of epilepsy patients at-risk for adverse outcomes related to switching antiepileptic drug products
    • Site PI: Tricia Ting and James Polli
    • Contract #: HHSF223201400188C
  • Pharmacokinetic studies of tacrolimus in transplant patients
    • Site PI: Rita Alloway
    • Grant #: 1U01FD004573-01
  • Evaluation of clinical and safety outcomes associated with conversion from brand-name to generic tacrolimus products in high risk transplant recipients
    • Site PI: Rita Alloway
    • Contract #: HHSF223201310224C
  • Retrospective analysis on the impact of generic immunosuppressants on acute rejection and long term graft survivals
    • Site PI: Alan Leichtmann, Arbor Research Collaborative for Health
    • Grant #: 1 U01FD005274-1
  • Prospective study comparing brand and generic immunosuppression on transplant outcomes, adherence, and immune response
    • Site PI: Suphamai Bunnapradist
    • Grant #: 1U01FD005271-01
  • Open-labeled pharmacokinetic and pharmacodynamic (PK-PD) studies of Metoprolol ER
    • Site PI: Larisa Cavallari
    • Grant #: 1U01FD005235-01
  • Bioequivalence and clinical effects of generic and brand Bupropion
    • Site PI: Evan Kharasch
    • Grant #: 1U01FD004899-01
  • A pharmacokinetic/pharmacodynamic study of methylphenidate formulations in pediatric attention-deficit/hyperactivity disorder (ADHD) patients in a laboratory classroom
    • Site PI: Thomas Spencer
    • Grant #: 1U01FD005240-01

Publications and Presentations

  • Shokati T, Bodenberger N, Vinks A, Jiang W, Alloway R, Christians U. Therapeutic drug monitoring of the immunosuppressant tacrolimus on dried blood spots using LC-MS/MS. J Vis Exp;(105):e52424. Doi: 10.3791/52424 (Nov 8, 2015)
  • Privitera MD, Welty TE, Gidal BE, Diaz FJ, Krebill R, Szaflarski JP, Dworetzky BA, Pollard JR, Elder EJ Jr, Jiang W, Jiang X, Berg M. Generic-to-generic lamotrigine switches in people with epilepsy: the randomised controlled EQUIGEN trial.Lancet Neurol;15(4):365-72 (Apr 2016)
  • Das S, Tung R, Ting TY, Polli J. Frequency of generic brittleness in epilepsy patients. AAPS Annual Meeting, Denver CO (2016)
  • Alloway R, Results of brand, generic hi and generic lo tacrolimus pharmacokinetic studies in kidney and liver transplant recipients, presentation at American Transplant Congress (May 2-6, 2015)
  • Vossler DG, Anderson GD, Bainbridge J. AES Position Statement on Generic Substitution of Antiepileptic Drugs. Epilepsy Current. 16:209-211 (2016)


The results of the two bioequivalence studies with lamotrigine IR tablets, conducted in patients with epilepsy under clinical conditions, support the validity of the FDA bioequivalence standards. As a result, the American Epilepsy Society (AES) withheld its 2007 position statement opposing generic substitution of antiepileptic drugs (AEDs) without physician and patient approval. In 2016, the AES published a new position statement acknowledging that drug formulation substitution with FDA-approved generic products reduces cost without compromising efficacy.


Back to Top