As of August 2026, acute post-surgical pain has an approved non-opioid sodium channel blocker and a second program with published Phase 2b data. Journavx, the first NaV1.8 inhibitor to reach the market, was approved in January 2025 for moderate to severe acute pain. In late July the New England Journal of Medicine published Phase 2b results for LTG-001, a selective NaV1.8 inhibitor from Latigo Biotherapeutics, in 343 adults after abdominoplasty, with a placebo-adjusted summed pain intensity difference over 48 hours of 62.1 at the high dose and 52.3 percent of those patients completing 48 hours without a rescue opioid against 22.1 percent on placebo. Latigo priced an upsized 345.6 million dollar initial public offering days later.
The unresolved questions have moved to chronic neuropathic pain. When Vertex sought a broad peripheral neuropathic pain label for Journavx, the FDA did not support one, and both of the company's NaV programs are now in diabetic peripheral neuropathy, with two Phase 3 studies expected to complete enrollment by the end of 2026. Dogwood Therapeutics has enrolled 217 patients in a Phase 2b trial of Halneuron, which it describes as the first synthetic formulation of tetrodotoxin and as a NaV1.7 analgesic, in chemotherapy induced neuropathic pain. Tetrodotoxin blocks the TTX-sensitive isoforms as a group rather than NaV1.7 alone. The company expects topline data this fall and has scheduled a KOL event for September 1 to review interim results, so this picture may look different within weeks.
Chronic Neuropathic Pain Asks for a Different Study
The acute indication is served by short models. A rodent plantar incision study places a 1 cm incision through skin, fascia and muscle of the hind paw, runs ten days, and reads out on von Frey withdrawal force, heat stimuli and dynamic weight bearing against morphine and bupivacaine. The insult is defined, the phenotype is immediate, and the whole question resolves within two weeks.
Chronic neuropathic pain does none of that. The phenotype develops over weeks against established axonal injury, it does not resolve on its own, and withdrawal thresholds alone are a thin basis for a durability claim. Studies run longer, large species become relevant for the tissue volume and the neurophysiology, and the readouts that carry weight are the ones a clinician also uses, including nerve conduction velocity and intraepidermal nerve fiber density.
Where MD Biosciences Sits in That Shift
The target itself has been characterized in tissue in a large species. Peripheral neuritis trauma is a porcine model of peripheral neuritis rather than of chemotherapy induced neuropathy, and work published with collaborators in Neurobiology of Pain used chemomorphometric analysis of skin biopsies from those animals to show reduced intraepidermal nerve fiber density alongside raised NaV1.7 and CGRP immunolabeling in epidermal keratinocytes, a profile the authors report as consistent with human neuropathic pain conditions. Allodynia is established by day 28 with a 75 percent responder rate, and a systematic review of twenty-three porcine pain models ranked PNT highest for pain intensity and duration. For a molecule aimed at NaV1.7, that is the target quantified in tissue where a model shows it upregulated.
For diabetic peripheral neuropathy, the indication both Vertex programs are now pursuing, MD Biosciences runs the Zucker Diabetic Fatty rat, where type 2 diabetes and sensory neuropathy develop on a genetic background rather than through acute beta cell ablation. Over thirteen weeks, ZDF animals held mechanical withdrawal thresholds near 5 g against roughly 26 g in controls. A streptozotocin model in rats and mice covers type 1 induction, with sensory nerve conduction velocity significantly reduced against naive animals and no improvement under pregabalin at 30 mg/kg. Streptozotocin induction is established in the pig as well, where it has supported published diabetic wound healing work, so a diabetic study can be run in the species whose peripheral neurophysiology tracks human most closely.
For chemotherapy induced neuropathic pain, models in mice and rats use taxol, cisplatin, vincristine or oxaliplatin over fourteen to twenty-eight days, with von Frey, hot plate and acetone testing, histology and cytokine analysis, and gabapentin or pregabalin as reference compounds. An in vitro dorsal root ganglion assay measures neurite area and axonal blebbing after cisplatin exposure, which distinguishes protecting the axon from quieting it.
MD Biosciences runs rodent and porcine post-operative pain models, the porcine PNT model of peripheral neuritis, diabetic neuropathy models in rats, mice and pigs, chemotherapy induced neuropathic pain models in mice and rats, and in vitro DRG neurodegeneration assays. For study design questions on non-opioid or ion channel pain programs, contact neuro@mdbiosciences.com.
References
Latigo Biotherapeutics, NEJM publication of LTG-001 abdominoplasty Phase 2b results, July 29 2026; N Engl J Med DOI 10.1056/NEJMoa2602910. SPID48 values are placebo-adjusted differences. Latigo Biotherapeutics, pricing of upsized $345.6 million initial public offering, August 6 2026.
Dogwood Therapeutics, Halneuron KOL event announcement, August 17 2026; enrollment of 217 patients reported in second quarter 2026 results, August 13 2026.
Fierce Pharma, "Vertex narrows near-term development plan for Journavx after FDA naysays broad label in neuropathic pain," August 5 2025; Vertex Pharmaceuticals second quarter 2026 results, August 3 2026.
Rice FL, Castel D, Ruggiero E, Dockum M, Houk G, Sabbag I, Albrecht PJ, Meilin S. Human-like cutaneous neuropathologies associated with a porcine model of peripheral neuritis: A translational platform for neuropathic pain. Neurobiology of Pain. 2019;5:100021. Castel D et al. 2016, original porcine PNT model. Meijs S et al. 2021, Lab Animal, systematic review of twenty-three porcine pain models.