Summary: SBI-810, an experimental non-opioid compound developed at Duke University School of Medicine, shows promise for providing strong pain relief without the addictive euphoria and dangerous side effects associated with traditional opioids. Unlike opioids that activate multiple intracellular pathways, SBI-810 selectively stimulates a single receptor signaling route linked to pain suppression, reducing the risk of addiction and other opioid-related harms.
In rodent studies, SBI-810 delivered effective analgesia for surgical pain, bone fractures, and nerve injury. The compound worked well on its own and enhanced the pain-relieving effects of opioids when used together at lower doses, without producing tolerance. It also compared favorably to existing medications such as gabapentin, offering pain control without sedation or memory impairment. SBI-810 accomplishes this by engaging neurotensin receptor 1 (NTSR1) and favoring a β-arrestin-2 signaling pathway through an approach called biased agonism, which directs receptor activity toward therapeutic outcomes and away from pathways tied to adverse effects.
Key Facts:
- Precision Targeting: SBI-810 selectively activates a β-arrestin-2–linked pain-relief pathway via neurotensin receptor 1, rather than broadly activating multiple pathways associated with opioid side effects.
- No Tolerance or Sedation: In mice, repeated SBI-810 treatment did not produce tolerance or common negative effects such as sedation and cognitive impairment.
- Broad and Enhanced Effectiveness: The compound reduced pain from surgical incisions, fractures, and neuropathic injury, and it potentiated opioid analgesia at lower opioid doses.
Source: Duke University
Overview
SBI-810 represents a new class of pain therapeutics that target a specific receptor system in the peripheral and central nervous system. While conventional opioid drugs act broadly on multiple intracellular signaling cascades—producing both analgesia and unwanted effects such as euphoria, respiratory depression, constipation, and dependence—SBI-810 is designed to bias receptor signaling toward beneficial outcomes. By acting as an arrestin-biased allosteric modulator of NTSR1, it engages mechanisms that reduce pain signaling without activating pathways associated with addiction and many adverse effects.
Published May 19 in Cell, the preclinical work shows that SBI-810 reduces behavioral and physiological signs of pain in several rodent models—postoperative, inflammatory, and neuropathic pain—after both systemic and local administration. The drug’s analgesic effects depend on NTSR1 and β-arrestin-2 (βarr2), and do not require NTSR2 or βarr1, indicating a specific molecular mechanism of action.
Senior author Ru-Rong Ji, PhD, who leads the Duke Anesthesiology Center for Translational Pain Medicine, emphasized the importance of a compound that is both analgesic and non-opioid in mechanism. In animal tests, SBI-810 prevented the development of tolerance and did not cause constipation—two common and clinically significant problems with opioid therapy. The compound also reduced opioid-induced conditioned place preference, lessening indicators of drug reward, and alleviated signs of chronic opioid withdrawal in behavioral assays.
Duke researchers found that SBI-810 suppressed excitatory synaptic transmission in spinal nociceptive circuits, inhibited NMDA receptor and ERK signaling in spinal neurons involved in pain processing, lowered Nav1.7 channel surface expression and reduced action potential firing in primary sensory neurons, and dampened C-fiber responses. These combined peripheral and central effects likely underlie the compound’s broad antinociceptive profile.
Compared with existing options, SBI-810 outperformed gabapentin in some measures of neuropathic pain and avoided the sedation and memory deficits commonly seen with that drug. In direct comparisons to oliceridine, a newer opioid used in clinical settings, SBI-810 produced superior outcomes on certain measures and showed fewer signs of distress in treated animals.
SBI-810 is still in early development, but Duke investigators are preparing for human studies and have secured multiple patents for the discovery. The research team notes the pressing need for safer analgesics: chronic pain affects a large portion of the population, and opioid-related overdose deaths remain a major public health problem.
Funding: The study was supported by the National Institutes of Health (NIH) and the U.S. Department of Defense.
Additional Duke authors on the paper include first authors Ran Guo and Ouyang Chen, along with Sangsu Bang, Sharat Chandra, Yize Li, Gang Chen, Rou-Gang Xie, Wei He, Jing Xu, Richard Zhou, Shaoyong Song, Ivan Spasojevic, Marc G. Caron, William C. Wetsel, and Lawrence S. Barak.
About this neuropharmacology research news
Author: Shantell Kirkendoll
Source: Duke University
Contact: Shantell Kirkendoll – Duke University
Image credit: Neuroscience News
Original Research: Open access. “Arrestin-biased allosteric modulator of neurotensin receptor 1 alleviates acute and chronic pain” by Ru-Rong Ji et al., published in Cell.
Abstract (concise summary)
Arrestin-biased allosteric modulator of neurotensin receptor 1 alleviates acute and chronic pain
Previous work has shown that G-protein–biased agonists can influence opioid analgesia through interactions with β-arrestin-2 signaling. Researchers earlier reported that SBI-553, a positive allosteric modulator of NTSR1 biased toward β-arrestin-2, reduces psychostimulant effects in mice. The present study demonstrates that the related compound SBI-810 produces robust antinociception across multiple rodent pain models when given systemically or locally. Its effects require NTSR1 and β-arrestin-2 but are independent of NTSR2 and β-arrestin-1.
Mechanistically, SBI-810 decreases excitatory synaptic input, inhibits NMDA receptor– and ERK-mediated signaling in spinal nociceptive neurons, reduces Nav1.7 channel availability and firing in primary sensory neurons, and attenuates C-fiber activity. Behaviorally, it diminishes opioid-induced conditioned place preference, relieves constipation, and lessens chronic opioid withdrawal signs. These findings support NTSR1-biased allosteric modulation as a promising non-addictive strategy for treating acute and chronic pain through coordinated peripheral and central actions.