In vitro and in vivo assessment of the abuse potential of PF614, a novel BIO-MD™ prodrug of oxycodone

Authors

  • D. Lynn Kirkpatrick, PhD
  • William K. Schmidt, PhD
  • Ricardo Morales, BSc
  • John Cremin, PhD
  • Julie Seroogy, BSc
  • Craig Husfeld, PhD
  • Thomas Jenkins, PhD

DOI:

https://doi.org/10.5055/jom.2017.0366

Keywords:

opioid abuse deterrence, Bio-MDTM oxycodone prodrug, PF614, extended-release opioid

Abstract

Objective: The need for pain medication which will not lead to abuse is well recognized. Ensysce has designed prodrug analogs of the commonly used pain medications including hydromorphone, oxycodone (OC), hydrocodone, and morphine that limit their use to oral delivery, two of which are in clinical development. This study was undertaken to demonstrate that PF614, an extended-release prodrug of OC, allows the release of OC as designed when delivered orally, yet it resists ex vivo extraction with household chemicals and is pharmacologically inactive when administered by nonoral routes (nasal and parenteral), thereby substantially reducing its intravenous (IV) and intranasal abuse potential.

Methods: In vitro and in vivo methods were used to determine release of OC from PF614 and to show potential μ-opioid receptor activity. Plasma and cerebral spinal fluid levels of OC were evaluated following in vivo IV administration of PF614 in rats. In vitro extraction of OC from PF614 was explored using enzymes, common solvents, and household chemicals at room temperature and elevated temperature over time to determine release of OC from the prodrug.

Results: PF614 was stable with in vitro exposure to human plasma, saliva, and liver microsomes or culinary enzyme preparations. PF614 was stable (90 percent remaining as intact prodrug) under all room temperature conditions evaluated for 24 hours. At 80 °C for 1 hour, no OC was released. Incubation at 80 °C for 24 hours in vinegar or vodka produced a conversion to OC of 6 percent. Incubation with trypsin at 37 °C converted PF614 approximately stoichiometric to OC with half-life of 4 hours. PF614's penetration of the central nervous system was 83-fold lower than OC and it had a 6.5-fold reduced potency as a μ-opioid agonist. Finally, oral PF614 delivers OC into plasma with an extended-release profile in dogs (reduced Cmax; delayed Tmax).

Conclusions: The Bio-Activated Molecular Delivery prodrug design limits the use of PF614 to the intended oral route of delivery with reduced potential for IV or nasal abuse, as it cannot be activated intravenously or nasally to provide an active opioid. Unlike existing opioid formulations, the extended-release profile of PF614 cannot be accelerated by chewing or ex vivo extraction to pharmacologically active substances.

Author Biographies

D. Lynn Kirkpatrick, PhD

CEO, Ensysce Biosciences Inc., San Diego, California

William K. Schmidt, PhD

Ensysce Biosciences Inc., San Diego, California

Ricardo Morales, BSc

Signature Therapeutics Inc., Palo Alto, California

John Cremin, PhD

Signature Therapeutics Inc., Palo Alto, California

Julie Seroogy, BSc

Signature Therapeutics Inc., Palo Alto, California.

 

Craig Husfeld, PhD

Signature Therapeutics Inc., Palo Alto, California

Thomas Jenkins, PhD

Signature Therapeutics Inc., Palo Alto, California

References

Manchikanti L, Singh A: Therapeutic opioids: A ten-year perspective on the complexities and complications of the escalating use, abuse, and nonmedical use of opioids. Pain Physician. 2008; 11(2)(suppl): S63-S88.

Dowell D, Haegerich T, Chou R: CDC guideline for prescribing opioids for chronic pain-United States, 2016. MMWR Recomm Rep. 2016; 65(1): 1-49.

IOM (Institute of Medicine): Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research. Washington, DC: National Academies Press, 2011.

Moskovitz BL, Benson CJ, Patel AA, et al.: Analgesic treatment for moderate-to-severe acute pain in the United States: Patients' perspectives in the Physicians Partnering Against Pain (P3) survey. J Opioid Manag. 2011; 7(4): 277-286.

Farré M, Camí J: Pharmacokinetic considerations in abuse liability evaluation. Br J Addict. 1991; 86(12): 1601-1606.

Webster L, Bath B, Medve R, et al.: The effect of different Cmax/Tmax ratios on euphoria and liking following oral oxycodone dosing in opioid-experienced, nondependent, recreational drug users. Paper presented at: the American Academy of Pain Medicine 25th Annual Meeting, January 28–31, 2009, Honolulu, HI.

Webster LR, Bath B, Medve RA, et al.: Randomized, double-blind, placebo-controlled study of the abuse potential of different formulations of oral oxycodone. Pain Med. 2012; 13(6): 790-801.

Harris SC, Perrino PJ, Smith I, et al.: Abuse potential, pharmacokinetics, pharmacodynamics, and safety of intranasally administered crushed oxycodone HCl abuse-deterrent controlled-release tablets in recreational opioid users. J Clin Pharmacol. 2014; 54(4): 468-477.

Singh R, Chang SY, Taylor LC: In vitro metabolism of a potent HIV-protease inhibitor (141W94) using rat, monkey and human liver S9. Rapid Commun Mass Spectrom. 1996; 10: 1019-1026.

Pain Therapeutics, Inc.: NDA 22-324: REMOXY XRT™ (Oxycodone Controlled-Release) Capsules CII. Advisory Committee Briefing Materials for the Anesthetic Life Support Drugs Advisory Committee Meeting of November 13, 2008. Pain Therapeutics, Inc., San Mateo, CA, 2008. Available at www.fda.gov/ohrms/dockets/ac/08/briefing/2008-4395b1-02-PAIN.pdf. Accessed June 7, 2016.

Fisher D, Magruder J, Konstantatos A, et al.: First-in-man evaluation of PF329: A abuse-resistant prodrug of hydromorphone. J Pain. 2012; 13(4)(suppl): S76.

Shafer S, Husfeld C, Magruder J: Pharmacokinetics of a trypsin-labile extended-release hydromorphone prodrug in healthy volunteers. PAINWeek. 2013: 245. Available at http://conference.painweek.org/media/mediafile_attachments/00/650-painweek2013acceptedabstracts.pdf. Accessed June 7, 2016.

Sellers EM, Shram MJ, Schoedel KA: The US FDA draft guidance for developing abuse-deterrent opioid analgesics: 2014 and beyond. Pharmaceut Med. 2014; 28: 317-327.

Jenkins T, Husfeld C, Cremin J, et al.: Abuse-resistant opioid prodrugs that demonstrate oral overdose protection. J Pain. 2012; 13(4): S73.

Published

01/01/2017

How to Cite

Kirkpatrick, PhD, D. L., W. K. Schmidt, PhD, R. Morales, BSc, J. Cremin, PhD, J. Seroogy, BSc, C. Husfeld, PhD, and T. Jenkins, PhD. “In Vitro and in Vivo Assessment of the Abuse Potential of PF614, a Novel BIO-MD™ Prodrug of Oxycodone”. Journal of Opioid Management, vol. 13, no. 1, Jan. 2017, pp. 39-49, doi:10.5055/jom.2017.0366.