# Biased Kappa Opioid Agonists as Non-addictive Analgesics

> **NIH NIH R01** · WAKE FOREST UNIVERSITY HEALTH SCIENCES · 2022 · $734,627

## Abstract

Biased Kappa Opioid Agonists as Non-addictive Analgesics. Prescription opioid abuse has increased
dramatically over the last decade and now comprises the largest growing substance abuse problem in the
United States. These abused medications are mu opioid agonists, and alternatives for pain treatment are
needed. Kappa opioid receptor (KOR) agonists are analgesic in humans and have low abuse liability, however
the dysphoric and sedating properties of these compounds have precluded their clinical utility and
development. Recently several groups have discovered that the analgesic properties are mediated through G-
protein signaling, while the sedating and dysphoric effects are mediated through non-G-protein pathways, likely
either ßarrestin2 or ERK1/2. Interestingly, several groups have described KOR agonists that preferentially
activate G-protein pathways over ßarrestin or ERK1/2 pathways, termed biased KOR agonists. These
compounds are promising candidates as non-addictive analgesics that will be devoid of the sedating and
dysphoric effects of other typical KOR agonists. We have recently demonstrated that one such compound
produces antinociception in mice and rats without evidence of sedation and dysphoria. Further this compound
does not interfere with forebrain dopamine neurotransmission, thought to underlie the untoward effects of
typical KOR agonists. The extent and nature of signaling bias is determined in vitro, using cell-based assays.
As such, it is not readily apparent how this signaling bias in vitro translates into improved pharmacology in vivo.
These compounds have been explored as analgesics primarily using non-clinically relevant pain assays, such
as tail flick or hot plate tests in rodents, and these assays do not generally predict clinical efficacy. In this
application we propose to assess a wide profile of signaling bias for KOR agonists developed using two distinct
chemical scaffolds, and to determine the relationship between intracellular signaling bias across multiple
pathways in native neuronal tissue (striatum and dorsal root ganglia) with in vivo efficacy in dysregulation of
dopamine neurochemistry and production of antinociception, sedation/dysphoria, and abuse liability using
clinically relevant rodent models of inflammatory, post-operative, and neuropathic pain, and drug self-
administration. Additionally we will assess the role of gender in signaling bias efficacy, as females have been
shown to be more sensitive to the analgesic effects of KOR agonists and less sensitive to the dysphoric
effects. We hope to determine a profile of signaling bias in vitro that translates into an improved
pharmacological profile for KOR agonists in vivo that can be used for further drug development and
mechanistic studies.

## Key facts

- **NIH application ID:** 10348175
- **Project number:** 5R01DA048490-04
- **Recipient organization:** WAKE FOREST UNIVERSITY HEALTH SCIENCES
- **Principal Investigator:** SARA RAULERSON JONES
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $734,627
- **Award type:** 5
- **Project period:** 2019-04-15 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10348175

## Citation

> US National Institutes of Health, RePORTER application 10348175, Biased Kappa Opioid Agonists as Non-addictive Analgesics (5R01DA048490-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10348175. Licensed CC0.

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