Clinical Challenges in the Abuse Potential Assessment of CNS-Active Drugs: Investigator Perspectives with a Special Commentary from a Study Volunteer

The field of abuse potential is rapidly changing with evolving regulatory requirements for clinical methodology assessing abuse potential (liability). Prescription drug abuse continues to be a great concern and regulatory agencies require abuse potential evaluation to inform appropriate drug scheduling for novel CNS-active drugs. In addition, many pharmaceutical companies have been developing abuse-deterrent formulations to address the concerns of prescription opioid abuse by both intended and unintended routes of administration. Such formulations have a unique set of study requirements to evaluate the integrity of the formulation and its ability to uphold reduced abuse potential (abuse deterrence). In many cases, regulatory agencies such as the Food and Drug Administration (FDA) and Health Canada require the assessment of abuse potential in the clinical trial setting. Several guidances have been issued by both agencies that cover the abuse potential evaluation of both CNS active drugs as well as abuse-deterrent (tamper-resistant) opioids^1-4. In all cases, the guidances specifically refer to the human abuse potential study and the recommended methodological approaches to conduct these studies.

Human abuse potential studies are a type of clinical study evaluating subjective and objective drug effects related to abuse potential and impairment. The preferred design is a randomized, double-blind, placebo- and positive-controlled crossover study. The studies are generally conducted in drug- experienced, non-dependent recreational drug users who have a past and recent history of using a drug in the pharmaceutical class of the test drug. In some cases, such studies have also included dependent subjects, however, the clinical trial methods require considerable adaptation due to the nature of the population. Generally, these studies are considerably distinct compared to healthy volunteer and patient studies, and host their own complexities and challenges. The drug using population represents a unique subgroup requiring adaptions to clinical trial methodology. Challenges with these populations include, but are not limited to, compliance with restrictions around concomitant medication and drug use, risk-taking behavior, and prior addictive disorders. The population needs to be carefully selected and screened to ensure that safety is not compromised, eligibility requirements are met, appropriate discrimination between the active control versus placebo is established, and that subjects are able to comply with the study requirements. Furthermore, a population using drugs by a specific route (e.g. intranasal, intravenous) may be needed if the clinical trial intends to study unintended routes of administration, as is often the case in studies evaluating abuse-deterrent formulations. Understanding the profile and nature of the population and the study requirements ensures appropriate rigidity in the methods and conduct of such studies.

This session will provide a unique perspective of these trials and their challenges, namely from the Investigator, study scientist, and most importantly, the study subject.

The purpose of this webinar is to:

1. Understand the regulatory requirements and methodological approaches for human abuse potential studies.
2. Learn to identify if your compound may require abuse potential evaluation.
3. Discover the challenges with these studies and this unique clinical trial population.
4. Appreciate the perspective and experience of participating in these studies from the actual study subjects during a live subject interview.

References
[1]Draft Guidance for Industry: Assessment of Abuse Potential of Drugs. U.S. Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (CDER). Jan. 2010.
[2]Guidance for Industry: Abuse-Deterrent Opioids – Evaluation and Labeling. U.S Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (CDER). April 2015.
[3]Guidance for Industry. Clinical Assessment of Abuse Liability for Drugs with Central Nervous System Activity. Health Canada. Dec. 2007.
[4]Draft Guidance for Industry: Tamper-resistant Formulations of Opioid Drug Product Submission. Health Canada. Dec. 2014.

Speakers

Dr. Beatrice Setnik, Vice President, Clinical Pharmacology, Early Phase, INC Research

Dr. Setnik has been working in the area of CNS research for over 16 years and is an expert in the area of abuse potential evaluation and clinical drug development. Dr. Setnik is currently the Vice President of Clinical Pharmacology at INC Early Phase and oversees the medical and scientific affairs groups. Dr. Setnik earned her doctorate degree in Pharmacology and the Collaborative Program in Neuroscience from the University of Toronto (Toronto, Canada). In her previous role as Senior Director, Clinical Sciences (King Pharmaceuticals and Pfizer, Inc), Dr. Setnik lead the clinical development and lifecycle management, including abuse potential evaluation, of several pain compounds including abuse deterrent opioid formulations. In her previous role as a Research Scientist (formerly Ventana /Decisionline Clinical Research, Toronto, Canada), Dr. Setnik was responsible for providing scientific input on various specialty phase I-II clinical trials including abuse potential studies for CNS drugs. Dr. Setnik has published numerous research articles in internationally recognized peer-reviewed journals and has presented at many scientific meetings and conferences. In addition, she chairs the clinical sub- team within the Cross Company Abuse Liability Consortium and has been an active member since 2008. Dr. Setnik is also an active member and participant in several congresses including the College on Problems of Drug Dependence. She has also been actively engaged in many aspects of abuse potential assessment including clinical development, regulatory submissions, developing patient reported outcome instruments, and contributing to post-marketing surveillance studies.

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Dr. Pierre Geoffroy, Vice President, Early Phase, INC Research

Dr. Geoffroy is a practicing physician specializing in addiction treatment in Ontario, Canada (First Step Medical Clinics). Since 2011, he has been the Vice President of INC Research, Early Phase (Toronto, Canada), where he serves as the site head and principal investigator on various early stage clinical trials, including studies with drugabusing populations. Dr. Geoffroy has over 25 years of experience in the medical field and in Pharmaceutical research.
Dr. Geoffroy has worked in the field of addiction medicine since 2011. He earned his medical degree in 1989 from McGill University and completed residencies in family medicine and emergency medicine in 1992 and 1995, respectively. Since that time, he has practiced medicine in hospitals and clinics located in Ontario and Quebec.

Before joining INC Research in 2011, Dr. Geoffroy held a number of executivelevel positions with Pharmaceutical companies and clinical research organizations involved in drug research and development. His experience has included serving as a major contributor to IND and BLA submissions, overseeing drug development strategy, serving as principal investigator on over 300 pharmacokinetic and pharmacodynamic studies, designing and implementing clinical research protocols, directing Phase 1 to 4 studies, and health outcomes research.

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