Human Abuse Potential (HAP)

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A leader in the conduct of human abuse potential (HAP) trials

Human abuse potential (HAP) studies, also known as human abuse liability (HAL) studies, may be required by the FDA (FDA Guidance for Industry: Assessment of Abuse Potential of Drugs. Draft Guidance. 2017) to evaluate the abuse potential of new chemical entities (NCEs) that are in clinical development, particularly if the drug is CNS-active. The characterization of abuse liability can be dependent on many factors, including pharmacology, pharmacokinetics, and the intended population. Thus, the conduct of a HAP study as part of the clinical development plan allows the Sponsor and the FDA to determine the potential risk of abuse liability and propose proper risk mitigation and product scheduling.

At Apex Innovative Sciences, our scientific and medical teams have extensive expertise in clinical study design methodology, dose selection, and subject screening and selection criteria as well as regulatory agency experience that can support your protocols and prepare Sponsors for their review with the FDA’s Controlled Substance Staff (CSS). The Apex team has provided HAP clinical development and regulatory advice to Sponsors from pre-IND to NDA.

Hassman Research Institute (HRI) has an outstanding track record of success conducting trials assessing the abuse potential of drugs at its Marlton, NJ location (just twenty minutes from Philadelphia) which offers a purpose-built 60-bed inpatient unit. HRI’s clinical and medical teams have extensive experience in the evaluation and screening of recreational drug users for inclusion in HAP studies.


  • Scientific and Medical staff that are experienced in the assessment and characterization of behavioral and cognitive adverse events, key to successful HAP studies
  • Effective collaboration with respective vendors to ensure attainment of high-quality data and drug/placebo separation
  • Use of proprietary, empirically grounded Placebo-Control Reminder Script (PCRS) to further mitigate placebo response, which helps decrease study completion timelines
  • Medical and clinical teams trained in the evaluation and management of substance withdrawal
  • Capnography/pulse oximetry, pupillometry, and biophysical testing
  • Pharmacy facilities that supports Schedule I-IV drug storage

Staff Highlights

  • Principal Investigators with decades of substance abuse clinical experience
  • A clinical psychologist with specialization in addiction and pain who has served on advisory boards for addictions studies and that has experience co-writing HAP protocols and risk mitigation
  • Advanced degree-level raters highly experienced with HAP assessment scales
  • Pharmacy Director with expertise in preparing, dispensing, and dosing HAP trials
  • Scientific Affairs & Clinical Development team providing high-level scientific guidance and input on study designs, protocols, assessment measures, and medical/scientific feasibility


  • Large research database of recreational drug users including opioids, hallucinogens, stimulants, psychedelics, and benzodiazepine populations
  • 15+ full-time recruitment specialists including Director of Recruitment with 15 years’ experience recruiting for HAP studies and substance use trials
  • Location in major metropolitan region that is home to over 30 colleges and universities


  • Highly skilled medical team determining eligibility of participants for the trial (e.g., recreational use vs. DSM-5 substance use disorder)
  • Recruiters provide timely reminders about participants’ next visits during all study visits of the trial
  • Dedicated full-time drivers to transport subjects to and from the research site