RecruitingPhase 3NCT05643872
Dermatological
Pachyonychia Congenita
Also known as PC, keratin nail thickening, PC-1, PC-2
Pachyonychia congenita is an ultrarare autosomal dominant keratin disorder caused by heterozygous mutations in one of four keratin genes — KRT6A, KRT6B, KRT16, or KRT17 — which encode keratins expressed in nail bed, palmoplantar epidermis,
ORPHA:674 ↗Gene KRT6AGene KRT6BGene KRT16Gene KRT17Prevalence Less than 1 in 1,000,000Onset Congenital or early infancyAutosomal dominant
2
studies recruiting now
as of 7 Sept 2026
14
studies registered in total
as of 7 Sept 2026
1
countries with a recruiting site
as of 7 Sept 2026
9 Dec 2022
most recent study posted
among recruiting studies
Recruiting trials
RecruitingNCT02321423
International Pachyonychia Congenita Research Registry
Showing the 2 most recently updated recruiting studies, as recorded 7 Sept 2026. Live status on each study page.
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Countries with at least one recruiting site among the studies above, 7 Sept 2026. Tap a country to search trials there.
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About Pachyonychia Congenita
Pachyonychia congenita is an ultrarare autosomal dominant keratin disorder caused by heterozygous mutations in one of four keratin genes — KRT6A, KRT6B, KRT16, or KRT17 — which encode keratins expressed in nail bed, palmoplantar epidermis, and oral mucosa. The hallmark feature is severe, wedge-shaped hypertrophic nail dystrophy present from birth or early infancy, accompanied by highly debilitating plantar keratoderma that causes extreme pain with weight-bearing and is considered the greatest determinant of quality of life impairment. The International Pachyonychia Congenita Research Registry (IPCRR) has been instrumental in characterising the natural history of this condition.
Common clinical features
Severe, wedge-shaped subungual hyperkeratosis affecting all twenty nails, often with nail sheddingFocal plantar keratoderma with intensely painful blisters and calluses, causing significant gait impairmentOral leukokeratosis: white mucosal thickening of the tongue, cheeks, and gingiva from infancyFollicular hyperkeratosis (keratosis pilaris-like) on the trunk and extremitiesNatal or neonatal teeth in KRT17-related (PC-2) subtypeEpidermal cysts (pilosebaceous cysts) particularly in KRT17 subtypeLaryngeal involvement and hoarseness in some patients due to mucosal keratin abnormalities
From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.
Treatments being studied
1 in clinical development, from Open Targets (CC BY 4.0). Not medical advice.
Phase 1Sirolimus (Fyarro)
Before you apply
Things trial teams commonly ask about for Pachyonychia Congenita. Not eligibility rules; those are set by each study.
- The PC Project maintains the International Pachyonychia Congenita Research Registry (IPCRR) — enrolment in the registry is often a prerequisite for or facilitates entry into sponsored trials.
- Eligibility frequently requires genotypic subtyping (PC-6A, PC-6B, PC-16, PC-17 based on gene affected) — confirm which keratin gene is mutated and obtain the exact variant notation.
- Pain severity scoring (VAS or NRS) and plantar keratoderma grading are standard outcome measures; document baseline plantar pain levels and impact on ambulation before screening visits.
Related conditions
Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).