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Substitutability of Generic Drugs: Perceptions and Reality

Friday, November 18, 2016, 8:30 a.m. - 4:30 p.m. ET
Past Event

Hosted by Johns Hopkins Center of Excellence in Regulatory Science and Innovation (JH-CERSI) and the Food and Drug Administration (Center for Drug Evaluation and Research and Office of Chief Scientists's Office of Regulatory Science and Innovation)


Problem statement: Generic drugs accounted for approximately 88% of all drug prescriptions in the US. The FDA is entrusted to ensure all medications entering the U.S. market are safe and effective. Despite the high utilization of generic drugs, skepticism remains among some patients and physicians regarding the substitutability of generic drugs, e.g., antiepileptic drugs and immunosuppressant drugs. Given the high rate of generic drug utilization and in light of remaining skepticism regarding the substitutability, it is important that the FDA develop a range of tools to monitor marketed generic drugs to ensure they have the same safety and efficacy profile as their reference listed drugs. 

This workshop discussed industry/agency practices related to post-market surveillance and post-market research activities related to generic drugs, including development of methods and tools to conduct post-market surveillance, understanding public perceptions of generic drug quality and effectiveness, and verifying therapeutic equivalence via brand-to-generic switching studies in patients. The workshop provided timely communication of post-market research outcomes to the public and help identify future research needs in post-market surveillance of generic drugs.

The primary educational mission of the JH-CERSI is to expand the knowledge base and to engage in development of state-of-the-art tools and methods to support regulatory science needs.

Objective: This educational workshop aimed: 

  • To discuss current progress on generic drug surveillance method development, generic substitution study outcomes, and surveys about generic drugs
  • To build confidence in generic drugs by demonstrating FDA's commitment to monitoring these drugs in the post-market setting and presenting evidence to demonstrate equivalency 
  • To provide timely communication of the results of post-market research related to generic drugs
  • To help identify future research needs in post-market surveillance of generic drugs

Target audience: The intended audience for this workshop is wide and includes FDA scientists (including but not limited to pharmacologists and epidemiologists), external researchers (in academia and elsewhere), generic drug pharmaceutical industry representatives/scientists, generic drug policy makers, physicians, and patients. Since this workshop will present research on generic drugs in the post-market setting, there are implications for all of the above groups. Scientists not directly involved in the research being presented should be made aware of the research and findings, which may enable future collaborations. External researchers can learn what work has been done already in order to generate future research methods to answer continuing scientific questions. The generic drug industry and policy makers should be made aware of the generic drug post-market research findings, in order to guide future development of generic drugs and generic drug policies.

Agenda & Speakers

Speaker and discussant bios are available here

Welcome and Introduction

Robert M. Califf, M.D., MACC
Food and Drug Administration (FDA)

8:30-8:45 am

Session 1: Generic Industry/Office of Generic Drugs Surveillance Practice [Recording]

Moderator: Robert Lionberger, Ph.D.
FDA/Center for Drug Evaluation and Research (CDER)/Office of Generic Drugs (OGD)/Office of Research and Standards (ORS)

Office of Generic Drug Surveillance Practice
James Osterhout, Ph.D.
FDA/CDER/OGD/Clinical Safety Surveillance Staff (CSSS)

Generic Industry Surveillance Practice
Colin D'Cunha, MBBS, MHSc, FRCPC
Apotex Inc.

Post-market Surveillance Lab Investigation
Wenlei Jiang, Ph.D.

Bioequivalence and Characterization of Generic Drugs
Xinyuan Zhang, Ph.D.
FDA/CDER/OGD/ORS/Division of Quantitative Methods and Modeling (DQMM)

8:45-10:05 am

Panel Discussion

Colin D'Cunha, James Osterhout, Wenlei Jiang, Xinyuan Zhang

Ida-Lina Diak, PharmD 
FDA/CDER/Office of Surveillance and Epidemiology (OSE)/Office of Pharmacovigilance and Epidemiology (OPE)/Division of Pharmacovigilance I(DPVI)

Lucinda Buhse, Ph.D. 
FDA/CDER/Office of Pharmaceutical Quality (OPQ)/Office of Testing and Research (OTR)

10:05-10:30 am



10:30-10:45 am

Session 2: Public Perception of Generic Drugs [Recording]

Moderator: Jodi Segal, M.D., M.P.H.
Johns Hopkins University

Changing Physician and Patient Perceptions about Generic Drugs
Ameet Sarpatwari, J.D., Ph.D.
Brigham & Women’s Hospital

Epilepsy Patient Perspectives on Generic Bioequivalence 
Jenna Mathis, J.D. 
Epilepsy Foundation

Does Variation in the Physical Characteristics of Generic Drugs Affect Patients’ Experiences? Results from National Survey of Pharmacists and Patients
Ameet Sarpatwari, J.D., Ph.D.
Brigham & Women’s Hospital

10:45 -11:45 pm

Panel Discussion

Ameet Sarpatwari, Angela Ostrom

John Whyte, M.D., M.P.H.  
FDA/CDER/Office of the Center Director (OCD)/Professional Affairs and Stakeholder Engagement Staff (PASES)

John Peters, M.D.

Andrew Sperling, J.D., M.A.
National Alliance on Mental Illness

11:45-12:10 pm


12:10-1:00 pm

Session 3: Generic Substitution Studies in Patients [Recording]

Moderator: Jodi Segal, M.D., M.P.H.
Johns Hopkins University

Bioequivalence in Epilepsy Patients and Assessment of Generic Brittleness
Jim Polli, Ph.D.
University of Maryland School of Pharmacy, Baltimore

Tricia Ting, M.D.
University of Maryland Medical Center, Baltimore

Pharmacokinetic Studies of Epileptic Drugs in Patients [EQUIGEN], Multiple-dose Studies and Single Dose Studies
Timothy Welty, Pharm.D.
Drake University

Pharmacokinetic Studies of Tacrolimus in Transplant Patients
Rita Alloway, Pharm.D.
University of Cincinnati College of Medicine

1:00-2:10 pm

Panel Discussion

Jim Polli, Tricia Ting, Timothy Welty, Rita Alloway,

Gregory Krauss, M.D.
Johns Hopkins University

Renata Albrecht, M.D.,
FDA/CDER/Office of New Drugs (OND)/Office of Antimicrobial Products (OAP)/Division of Transplant and Ophthamology Products (DTOP)

2:10-2:30 pm


2:30-2:40 pm

Session 4: Generic Drug Surveillance Method Development [Recording]

James Osterhout, Ph.D.,

Effect of Therapeutic Class on Generic Drug Substitutions
Jodi Segal, M.D., M.P.H.
Johns Hopkins University

Postmarketing Surveillance of Generic Drug Usage and Substitution Patterns
Ilene Harris, Ph.D., Pharm.D.
IMPAQ International

Assessing the Post-marketing Safety of Authorized Generic Drug Products
Rishi Desai, Ph.D., M.S.
Brigham & Women’s Hospital

Post-market Authorized Generic Evaluation
Richard Hansen, Ph.D.
Auburn University

2:40-4:00 pm

Panel Discussion

Jodi Segal, Ilene Harris, Rishi Desai, Richard Hansen,

Michael Nguyen, M.D.,

Alex Secora, M.P.H.,
Johns Hopkins University

4:00-4:25 pm

Closing remarks

Caleb Alexander, M.D., M.P.H.
Johns Hopkins University

4:25 pm

Attendee Information & Directions

The public workshop will be held at FDA White Oak Campus, Building 31 Great Room (Room 1503A). Entrance for the public workshop participants (non-FDA employees) is through Building 1 where routine security check procedures will be performed. For parking and security information, please refer to the FDA information page

Public Internet Access Instructions:

Password: publicaccess

After selecting this network, open your internet browser- the FDA Wifi page should automatically load. If your browser displays a security error page before loading the FDA WiFi page, click “continue to this website.”

Lunch Information: If you would like to order a bagged lunch, please stop by the kiosk outside of the room to place your order and prepay by 10:30 am. 


For questions and concerns, please email Jodi Segal at or Wenlei Jiang at