Transcriptomic signature, bioactivity and safety of a non-hepatotoxic analgesic generating AM404 in the midbrain PAG region.

Safe and effective pain management is a critical healthcare and societal need. The potential for acute liver injury from paracetamol (ApAP) overdose; nephrotoxicity and gastrointestinal damage from chronic non-steroidal anti-inflammatory drug (NSAID) use; and opioids' addiction are unresolved challenges. We developed SRP-001, a non-opioid and non-hepatotoxic small molecule that, unlike ApAP, does not produce the hepatotoxic metabolite N-acetyl-p-benzoquinone-imine (NAPQI) and preserves hepatic tight junction integrity at high doses. CD-1 mice exposed to SRP-001 showed no mortality, unlike a 70% mortality observed with increasing equimolar doses of ApAP within 72 h. SRP-001 and ApAP have comparable antinociceptive effects, including the complete Freund's adjuvant-induced inflammatory von Frey model. Both induce analgesia via N-arachidonoylphenolamine (AM404) formation in the midbrain periaqueductal grey (PAG) nociception region, with SRP-001 generating higher amounts of AM404 than ApAP. Single-cell transcriptomics of PAG uncovered that SRP-001 and ApAP also share modulation of pain-related gene expression and cell signaling pathways/networks, including endocannabinoid signaling, genes pertaining to mechanical nociception, and fatty acid amide hydrolase (FAAH). Both regulate the expression of key genes encoding FAAH, 2-arachidonoylglycerol (2-AG), cannabinoid receptor 1 (CNR1), CNR2, transient receptor potential vanilloid type 4 (TRPV4), and voltage-gated Ca2+ channel. Phase 1 trial (NCT05484414) (02/08/2022) demonstrates SRP-001's safety, tolerability, and favorable pharmacokinetics, including a half-life from 4.9 to 9.8 h. Given its non-hepatotoxicity and clinically validated analgesic mechanisms, SRP-001 offers a promising alternative to ApAP, NSAIDs, and opioids for safer pain treatment.

Transcriptomic signature, bioactivity and safety of a non-hepatoxic analgesic generating AM404 in the mid-brain PAG region.

The safe and effective management of pain is a critical healthcare and societal need. The potential for misuse and addiction associated with opioids, nephrotoxicity, and gastrointestinal damage from chronic non-steroidal anti-inflammatory drug (NSAID) use, as well as acute liver injury from paracetamol (ApAP) overdose, are unresolved challenges. To address them, we developed a non-opioid and non-hepatotoxic small molecule, SRP-001. Compared to ApAP, SRP-001 is not hepatotoxic as it does not produce N-acetyl-p-benzoquinone-imine (NAPQI) and maintains hepatic tight junction integrity at high doses. SRP-001 has comparable analgesia in pain models, including the complete Freund's adjuvant (CFA) inflammatory von Frey. Both induce analgesia via N-arachidonoylphenolamine (AM404) formation in the midbrain periaqueductal grey (PAG) nociception area, with SRP-001 generating higher amounts of AM404 than ApAP. Single-cell transcriptomics of PAG uncovered that SRP-001 and ApAP also share modulation of pain-related gene expression and cell signaling pathways, including the endocannabinoid, mechanical nociception, and fatty acid amide hydrolase (FAAH) pathways. Both regulate the expression of key genes encoding FAAH, 2-AG, CNR1, CNR2, TRPV4, and voltage-gated Ca2+ channel. Interim Phase 1 trial results demonstrate SRP-001's safety, tolerability, and favorable pharmacokinetics (NCT05484414). Given its non-hepatotoxicity and clinically validated analgesic mechanisms, SRP-001 offers a promising alternative to ApAP, NSAIDs, and opioids for safer pain treatment.