Treatments in Development
Pre-clinical and early-stage drug candidates for erythromelalgia that are not yet in full clinical trials.
Last updated: April 14, 2026
Note: These treatments are in early development stages. Most are years away from approval. For active clinical trials, see the Clinical Trials page.
How These Treatments Work
Sodium Channel Blockers (Nav1.7/1.8)
Target sodium channels encoded by SCN9A gene. Mutations in SCN9A cause inherited erythromelalgia by increasing channel activity. Blockers reduce excessive nerve firing.
Pipeline drugs: STC-004, CC8464 (status uncertain), Funapide (discontinued), Vixotrigine (discontinued)
TRPV1 Inhibitors
Block TRPV1 pain receptors that detect heat and inflammation. TRPV1 activation contributes to burning pain sensations.
Pipeline drugs: XEN-D0501
Gene Therapy
Epigenetic modification to reduce SCN9A expression at the genetic level. Potential for long-lasting relief by addressing root cause.
Pipeline drugs: NT-Z001
⭐ Preparing for Clinical Trials
These candidates are closest to entering clinical trials for erythromelalgia.
XEN-D0501
Pila Pharma
Transient receptor potential vanilloid 1 (TRPV1) antagonist that down-regulates neurogenic inflammation to address pain and inflammatory conditions.
Key Highlights:
- Clinical trial application expected H1 2026
- Completed Phase 2a trials in obesity/diabetes showing good tolerability
- Animal studies demonstrated excellent safety after 13 weeks at high doses
- Estimated 3-year timeline to potential market approval
- 7-year regulatory exclusivity in US if approved
Clinical/Preclinical Data:
Phase 2a data (diabetes): Significantly enhanced endogenous insulin response and reduced cardiovascular biomarker ANP vs placebo
🧬 Novel Therapeutic Approaches
Breakthrough technologies and mechanisms not yet in traditional clinical trials.
NT-Z001
Navega Therapeutics
De-immunized epigenetic therapy using AI-enabled platform to precisely downregulate SCN9A gene expression without altering DNA sequence. Targets the Nav1.7 sodium channel encoded by SCN9A.
Key Highlights:
- Received $4M CIRM grant (February 2025) for IND-enabling studies
- Novel epigenetic editor technology - modifies gene expression without changing DNA
- Partnership with Charles River for AAV vector manufacturing
- Targets root cause (SCN9A gain-of-function mutation)
- AI-enabled platform for precision gene regulation
- Potential for long-lasting pain relief
Development Status:
Preclinical studies ongoing; IND application in preparation
🔬 Active Pipeline Candidates
Treatments in active development with ongoing research programs.
STC-004
Eli Lilly (acquired from SiteOne Therapeutics)
Nav1.8-selective inhibitor being developed for chronic pain conditions. While not specifically targeting erythromelalgia, Nav1.8 plays a role in peripheral pain signaling.
Key Highlights:
- Acquired by Eli Lilly May 2025 (up to $1B deal)
- Phase 2 ready for chronic pain indications
- Nav1.8 channel is expressed in peripheral pain neurons
- Non-opioid mechanism for pain management
- Major pharma backing (Lilly)
Development Status:
Phase 2 ready; primary indication is broader chronic pain (not EM-specific)
❓ Status Uncertain
Programs with unclear development status due to corporate restructuring, mergers, or lack of recent updates.
CC8464
Pelthos Therapeutics (via merger)
Orally bioavailable, potent, state-dependent inhibitor of NaV1.7 sodium ion channel for neuropathic pain conditions.
Program Highlights:
- Completed four Phase 1 trials with no dose-limiting tolerability concerns
- Preclinical efficacy demonstrated in multiple pain models
- Phase 2a trial was planned for erythromelalgia
- July 2025: Parent company merged; current development status not publicly confirmed
Historical Development Data:
Phase 1 completed. Phase 2a was planned for ~20 erythromelalgia patients with SCN9A mutations.
📋 Discontinued or Deprioritized Programs
Programs no longer in active development for erythromelalgia.
Funapide (XEN402, TV-45070)
Xenon Pharmaceuticals
Dual Nav1.7/Nav1.8 blocker evaluated in oral and topical formulations for erythromelalgia.
Program Highlights:
- Phase 2: 42% pain reduction in heat-induced pain tests vs placebo
- Tested in oral and topical formulations
- Development discontinued 2022
Clinical Data:
Phase 2 data showed significant pain reduction in erythromelalgia patients.
Vixotrigine (BIIB074)
Biogen
State-dependent Nav1.7 inhibitor. Completed Phase 2 in erythromelalgia; company focused on other indications.
Program Highlights:
- Completed Phase 2 trials in erythromelalgia
- Company prioritized trigeminal neuralgia program
- EM development not actively advancing
Clinical Data:
Phase 2 completed in erythromelalgia.
Development Timeline Overview
Clinical Trial Applications Expected
XEN-D0501 (Pila Pharma) preparing trial application for H1 2026
IND-Enabling Studies
NT-Z001 (Navega) advancing toward Phase 1 with $4M CIRM funding
Phase 2 Planning
CC8464 (Pelthos) and STC-004 (Lilly) in development for pain indications
About This Pipeline Data
Data Sources: This page is manually curated from company press releases, investor presentations, scientific publications, grant announcements, and merger disclosures. Unlike active clinical trials (which appear on ClinicalTrials.gov), pre-clinical and early-stage programs have no standardized reporting requirements.
Why Information Is Limited: Small biotech companies in the rare disease space frequently undergo corporate restructuring, mergers, or strategic pivots. Programs may be quietly deprioritized without formal announcements. Company pipeline pages and investor presentations may not reflect current development priorities.
Updates: We update this page as new information becomes available from credible sources. If you have information about these or other erythromelalgia programs in development, please contact us.
Important Disclaimer
This information is for educational purposes only. These treatments are experimental and not yet approved for erythromelalgia. Development timelines are estimates and subject to change. Most pipeline candidates are years away from potential approval. Always consult with your healthcare provider about treatment options.