NCT07323082

Brief Summary

Pseudoxanthoma elasticum (PXE) is a rare genetic disorder, transmitted as an autosomal recessive trait, affecting approximately 1 in 50,000 people, predominantly women. It is characterised by progressive calcification of tissues rich in elastic fibres, particularly the skin, retina and arteries. It often begins in young adults and can eventually lead to central blindness, peripheral artery disease, strokes, tendon pain, recurrent kidney stones and visible skin changes. The diagnosis is based on clinical examination (skin papules, angioid streaks) and can be confirmed by biopsy or genotyping of the ABCC6 gene, whose mutation leads to extracellular ATP deficiency. This deficiency reduces the production of pyrophosphate (PPi), a natural inhibitor of calcification, thus promoting abnormal calcium deposits in tissues. To date, there is no curative treatment, but clinical trials are evaluating oral administration of PPi, with encouraging results. The role of purinergic metabolism is increasingly being explored in PXE. The cascade of conversion of ATP to adenosine (ADO) via ectonucleotidase pyrophosphatase 1 (ENPP1) and 5' ectonucleotidase (NT5E) indirectly regulates the activity of tissue-nonspecific alkaline phosphatase (TNAP), an enzyme that degrades PPi. An imbalance in this cascade could aggravate calcifications. The joint measurement of PPi, ADO and these enzymes, which has recently become possible, could not only refine our understanding of the disease, but also pave the way for new therapeutic strategies.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
45

participants targeted

Target at P25-P50 for not_applicable

Timeline
32mo left

Started Jan 2026

Typical duration for not_applicable

Geographic Reach
1 country

2 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress10%
Jan 2026Jan 2029

First Submitted

Initial submission to the registry

December 16, 2025

Completed
22 days until next milestone

First Posted

Study publicly available on registry

January 7, 2026

Completed
13 days until next milestone

Study Start

First participant enrolled

January 20, 2026

Completed
12 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 15, 2027

Expected
2 years until next milestone

Study Completion

Last participant's last visit for all outcomes

January 15, 2029

Last Updated

April 24, 2026

Status Verified

April 1, 2026

Enrollment Period

12 months

First QC Date

December 16, 2025

Last Update Submit

April 23, 2026

Conditions

Pseudoxanthoma Elasticum

Keywords

ppiADOvascular pathology

Outcome Measures

Primary Outcomes (1)

  • potential role of the ADO

    mesure of concentration

    at inclusion

Secondary Outcomes (2)

  • correlation between ADO, PPi and ectoenzymatic activities

    at inclusion

  • correlation between ADO, PPi and calcification score

    at inclusion

Study Arms (2)

PXE Patient

EXPERIMENTAL

PXE Patient

Biological: supplementary tubes

NON PXE Patient

OTHER

NON PXE Patient

Biological: supplementary tubesRadiation: SCANNER

Interventions

SCANNERRADIATION

non-injected coronary and lower limb scanner

NON PXE Patient
supplementary tubesBIOLOGICAL

* One 2.5 ml EDTA blood tube for PPi measurement. * Special blotting paper for collecting blood drops for ADO measurement. * 7.5 ml whole blood for ectoenzyme measurement

NON PXE PatientPXE Patient

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Male or female,
  • Age \>18 years
  • Covered by social security,
  • Informed and having signed the informed consent form.
  • PXE patients:
  • \- with PXE defined according to current clinical criteria for PXE (REACT-PXE and PNDS consensus) and with an ABCC6 mutation.

You may not qualify if:

  • Patients treated with bisphosphonates, vitamin K antagonists, and dietary supplements containing calcium, phosphates, magnesium, zinc, or iron.
  • Treatments likely to alter adenosine levels (caffeine, salbutamol, beta-blockers, etc.).
  • Progressive bone diseases (osteoporosis, chondrocalcinosis, gout, etc.).
  • Progressive and/or treated cancerous diseases.
  • Progressive and/or treated inflammatory or autoimmune diseases.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Angers University hospital

Angers, France

NOT YET RECRUITING

Nice University hospital

Nice, France

RECRUITING

MeSH Terms

Conditions

Pseudoxanthoma Elasticum

Condition Hierarchy (Ancestors)

Hemostatic DisordersVascular DiseasesCardiovascular DiseasesHemorrhagic DisordersHematologic DiseasesHemic and Lymphatic DiseasesSkin AbnormalitiesCongenital AbnormalitiesCongenital, Hereditary, and Neonatal Diseases and AbnormalitiesSkin Diseases, GeneticGenetic Diseases, InbornConnective Tissue DiseasesSkin and Connective Tissue DiseasesSkin Diseases

Central Study Contacts

Georges LEFTHERIOTIS, PUPH

CONTACT

04 92 03 85 48leftheriotis.g@chu-nice.fr

Luc Froissant

CONTACT

04 92 03 85 48froissant.l@chu-nice.fr

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 16, 2025

First Posted

January 7, 2026

Study Start

January 20, 2026

Primary Completion (Estimated)

January 15, 2027

Study Completion (Estimated)

January 15, 2029

Last Updated

April 24, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will not share

Locations

FR(2)