| Requester | NeXus Neuroinformatics, Inc. Delaware C-Corporation · EIN 42-3415697 614 County Highway 325, Hamilton, Alabama 35570 |
| Primary Point of Contact | Marjorie McCubbins, Founder & Chief Executive Officer marjorie.mccubbins@nexusneurodata.com · (205) 570-2432 |
| Submission Date | June 29, 2026 |
| Regulatory Affairs Advisor | Robert Michalik, JD, RAC (pro bono) · North Conway, New Hampshire |
| Design Control Lead | Shailee Desai, M.S. Regulatory Affairs candidate (Northeastern University) |
| Project Title | Qualification of the Composite Neurochemical Stress-Resilience Biomarker Panel (CNSR-Panel) as a Pharmacodynamic Biomarker for Combat-Veteran Post-Traumatic Stress Disorder Drug Development |
| Submission Stage | Letter of Intent |
Approximately 13 percent of post-9/11 U.S. combat veterans carry a diagnosis of post-traumatic stress disorder (PTSD) (Veterans Affairs National Center for PTSD, 2022). Fewer than five new chemical entities have received U.S. Food and Drug Administration approval for the PTSD indication between 2000 and 2023; the dominant first-line pharmacotherapies (sertraline, paroxetine) date from the late 1990s and produce non-response in approximately 40 to 60 percent of treated combat-veteran patients (meta-analyses across SSRI/SNRI trials in combat-PTSD cohorts).
Phase 2 clinical trial attrition in PTSD drug development remains a major source of program failure, with single Phase 2 failures routinely costing sponsors $50 to $100 million and three to five years of program time. A material proportion of these failures are signal-detection failures attributable to trial-design constraints (heterogeneous biological subpopulations, unmatched endpoint timing, insufficient pharmacodynamic stratification) rather than to compound-level efficacy failure.
No FDA-qualified pre-clinical pharmacodynamic biomarker panel currently exists for combat-veteran PTSD drug development. Sponsors evaluating candidate compounds for this indication rely on rodent fear-conditioning models with limited translational fidelity to combat-trauma neurobiology, or construct ad-hoc biomarker measurement strategies on a per-trial basis. A qualified, composite, pharmacodynamic biomarker panel built on the established neurochemistry of combat-veteran PTSD would directly address this gap. Supporting evidence for the proposed CNSR-Panel includes 162 peer-reviewed citations across HPA-axis dysregulation, neuroinflammatory biology, neuropeptide-Y resilience, sex-steroid endocrinology, epigenetic regulation, and threat-circuit neuroimaging in OEF/OIF, Vietnam-era, and equivalent combat-veteran cohorts.
Name: Composite Neurochemical Stress-Resilience Biomarker Panel (CNSR-Panel)
Biomarker Type: Composite (multi-component) pharmacodynamic biomarker per BEST Glossary definitions, comprising seven peripheral and epigenetic measurements:
The seven-constituent composite captures three biologically distinct response axes implicated in combat-veteran PTSD pathophysiology: (1) hypothalamic-pituitary-adrenal axis regulation and stress-system adaptation (cortisol/DST, DHEA/cortisol ratio); (2) systemic neuroinflammatory tone (hs-IL-6, hs-CRP); (3) neuropeptide resilience signaling and epigenetic glucocorticoid receptor regulation (NPY, AIM2 methylation, FKBP5 methylation). Composite signature scoring is performed by the assessment method described in Section 5 and detailed in Section VII of the full Letter of Intent (Analytical Considerations).
The proposed CoU supports drug development decisions including candidate-compound stratification prior to first-in-human dosing, dose-range justification using exposure-response modeling against composite-panel shifts, and trial-enrichment criteria definition for Phase 1 and Phase 2 trial designs in the combat-veteran PTSD population. The CNSR-Panel is not proposed for individual patient diagnosis, individual patient treatment selection, stand-alone efficacy claims, or use outside the combat-veteran PTSD drug development setting.
The seven CNSR-Panel constituents are measured using standard clinical-laboratory and molecular biology techniques: enzyme-linked immunosorbent assay (ELISA) for plasma cortisol, DHEA, IL-6, CRP, and NPY using FDA-cleared or laboratory-validated immunoassay platforms; bisulfite-treated DNA sequencing or pyrosequencing for AIM2 promoter methylation and FKBP5 intron-7 methylation. Pre-analytical handling follows established standard operating procedures for plasma collection, freezing at −80°C, and methylation-grade DNA extraction.
Composite panel interpretation and pharmacodynamic response scoring is performed by NeXus AI, a chemistry-conditioned computational interpretation engine developed by the Requester. NeXus AI is a 32-million-parameter chemistry-conditioned transformer coupled to a 34-head Hodgkin-Huxley neurochemical cascade architecture, with SHA-256 cryptographically verifiable inference end-to-end, designed for FDA ALCOA+ data integrity and 21 CFR Part 11 electronic signature compliance. The platform is live at nexusneurodata.com and is available for public query. The underlying methodology is the subject of four pending U.S. provisional patent applications, held by parent Nexus Concordat, Inc., and exclusively licensed to NeXus Neuroinformatics, Inc. in the pharmaceutical and clinical research field of use: 63/939,190 (Substrate-Independent Memory Weighting Architecture); 63/962,385 (Neurochemical Language Model); 63/988,485 (AETHER: Adaptive Endocrine Transformer Heads with Emotional Regulation); 64/034,536 (Scyla: Biologically-Native Programming Language). Full technical description is provided in Section VII of the Letter of Intent.
Completed analytical work. A cardiac-specialty instantiation of the NeXus AI assessment architecture (cardiac_gen3) is deployed publicly at nexusneurodata.com and demonstrates the platform's deterministic, cryptographically verifiable inference behavior. Architectural stability and manifest-verification mechanisms have been validated on this specialty cell against published cardiac chemistry data.
Planned analytical validation. The Requester's planned analytical validation program for the CNSR-Panel includes: (a) construction and training of the psych_gen1 psychiatric specialty cell on the curated combat-veteran PTSD biomarker corpus; (b) analytical validation of each CNSR-Panel constituent measurement against reference clinical immunoassay performance standards (sensitivity, specificity, accuracy, intra-assay and inter-assay precision); (c) composite signature scoring validation against pre-specified internal calibration cohorts; (d) inter-operator and intra-operator variability characterization for the methylation measurements; (e) end-to-end manifest verification and ALCOA+ audit-trail performance testing under simulated regulated-environment conditions.
Completed clinical-evidence base. The Requester has curated and annotated 162 peer-reviewed citations supporting the clinical relevance of each CNSR-Panel constituent in combat-veteran PTSD cohorts, with strongest treatment-response evidence for plasma cortisol/DST, DHEA/cortisol ratio, and plasma NPY (notably the Yehuda et al. veteran intervention study correlating pre-treatment NPY with symptom reduction). Inflammatory constituents (hs-IL-6, hs-CRP) are supported by meta-analytic evidence of pro-inflammatory tone in combat-PTSD across multiple service eras. Epigenetic constituents (AIM2 promoter methylation, FKBP5 intron-7 methylation) are supported by emerging veteran-cohort epigenome-wide association data.
Planned clinical-validation program. The Requester proposes a three-stage validation pathway: (1) Retrospective directional validation — composite CNSR-Panel pharmacodynamic predictions generated by NeXus AI against the published outcomes of two to three completed veteran-PTSD intervention trials with known directional results, evaluated for prediction-vs-observation concordance; (2) Prospective pre-registered partner study — a collaboration with a Veterans Affairs or Department of War-affiliated clinical research site to pre-register NeXus AI predictions blinded against an upcoming combat-veteran PTSD intervention trial conducted by the partner, with outcome adjudication independent of the Requester and community-based participatory research (CBPR) integration per FDA guidance; (3) Peer-reviewed publication and qualification submission — submission of validation results to a peer-reviewed venue concurrent with submission of the Qualification Plan to the Biomarker Qualification Program.
The Requester has obtained pro-bono regulatory advisory engagement (Robert Michalik, JD, RAC) and is the invited keynote speaker at the Regulatory Affairs Professionals Society (RAPS) Boston Chapter webinar on August 12, 2026 ("When AI Hallucinates: From Architectural Root Cause to Auditable Solutions for Regulated Industries"), supporting the public-engagement and scientific-community-adoption objectives of the FDA Biomarker Qualification Program.