NCT04868578

Brief Summary

Pseudoxanthoma elasticum (PXE) is a rare inherited metabolic disorder (OMIM 264800, frequency 1/25000) characterized by progressive ectopic calcification of connective tissues. PXE mainly affects the skin (inesthetic papules and plaques in the skin folds), the retina (central blindness), the vasculature (peripheral arterial occlusive disease and stroke) and the renal system (renal lithiasis) in adulthood. Although rarely, early lethal forms have been reported. This chronic and highly disabling condition results from a loss of function of the gene encoding for the ABCC6 membrane transporter primarily expressed in the hepatocytes and renal tubular cells. Recently, it has been reported that PXE was characterized by a 50-60% decrease in the plasma level of inorganic pyrophosphate (PPi), a major physiological anti-calcifying factor. PXE is an incurable disease which therapeutic options are limited to symptomatic treatments to stem the devastating effect of the ectopic calcifications. Recently, encouraging proof of concept studies with animals PXE models and healthy volunteers have shown that, contrary to what was initially reported and thought, the oral administration of PPi salts are able to increase PPi plasma levels, opening up new therapeutic perspectives in PXE. Therefore, we propose to perform the first Phase II randomized controlled trial (RCT) to evaluate the safety and efficacy of a daily and oral administration of PPi salts against placebo in PXE patients.

Trial Health

77
On Track

Trial Health Score

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

Enrollment
99

participants targeted

Target at P50-P75 for not_applicable

Timeline
16mo left

Started Dec 2022

Longer than P75 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 Progress72%
Dec 2022Sep 2027

First Submitted

Initial submission to the registry

March 30, 2021

Completed
1 month until next milestone

First Posted

Study publicly available on registry

May 3, 2021

Completed
1.6 years until next milestone

Study Start

First participant enrolled

December 13, 2022

Completed
4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 13, 2026

Expected
9 months until next milestone

Study Completion

Last participant's last visit for all outcomes

September 1, 2027

Last Updated

May 17, 2024

Status Verified

May 1, 2024

Enrollment Period

4 years

First QC Date

March 30, 2021

Last Update Submit

May 16, 2024

Conditions

Outcome Measures

Primary Outcomes (1)

  • Arterial calcification score

    Using manufacturer dedicated software, the investigator, will determine the calcification score from CT images according to the validated Agatston score method. A threshold of 130 Hounsfield Units for calcium detection will be used for the study. Voxels above this threshold representing arterial wall calcifications will be manually identified and selected by the observer on the CT image. Calcifications mass in the studied arterial segments will be analyzed and quantified. The length and antero-posterior mean diameter of each arterial segment will be determined for further normalization of the calcification score to the arterial wall surface (data expressed as HU/mm2 of arterial surface). The intraclass correlation and Bland-Altman coefficient for inter-observer reliability of the total peripheral artery calcium mass measurement will be determined by scoring 10 random scans by two independent investigators.

    12 months

Secondary Outcomes (3)

  • clinical observation of dermatological changes

    12 months

  • clinical observation of ophtalmologic changes

    12 Montths

  • vascular changes

    12 months

Study Arms (2)

PPI

EXPERIMENTAL

the patient take PPI caps

Dietary Supplement: study treatment PPI

PPI placebo

PLACEBO COMPARATOR

The patient take PPI placebo

Dietary Supplement: Placebo comparator

Interventions

study treatment PPIDIETARY_SUPPLEMENT

patient take PPI every day during 12 months

PPI
Placebo comparatorDIETARY_SUPPLEMENT

patient take PPI placebo every day during 12 months

PPI placebo

Eligibility Criteria

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

You may qualify if:

  • Patients (\>18 years and \<65 years), men and women, presenting a clinically and biologically authenticated PXE (genotype + phenotype) according to the international diagnostic criteria (26).
  • Patient affiliated to a social security insurance
  • Signed informed consent
  • Patient without acute complication linked or not to the pathology at the time of the study
  • Renal insufficiency (i.e. defined by a renal clearance \<30ml / min / 1.73 m²)
  • Patients with osteomalacia
  • Patients with chronic diarrhea (\> 1 month)
  • Pregnancy, lactating or fertile women who may wish to become pregnant within three years.
  • Any other medical condition that may be considered in the opinion of the Principal Investigator.
  • Use of bisphosphonate during last 5 years.
  • Hypocalcemia (calcium \<2.20 mmol/L and ionized calcium \<1.15 mmol/L) \*.
  • Vitamin D deficiency \<35 nmol/L \*
  • Enrollment in another inteventional clinical trial which could interfere with the present study
  • patients (\>18 years) protected by law

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Angers Hospital

Angers, 49000, France

RECRUITING

Nice Hospital

Nice, 06000, France

RECRUITING

Related Publications (1)

  • Clotaire L, Rubera I, Duranton C, Gal J, Chamorey E, Humeau H, Yamani S, Chiaverini C, Willoteaux S, Padovani B, Mourozeau L, Mainguy A, Baillif S, Martin L, Leftheriotis G. The PROPHECI trial: a phase II, double-blind, placebo-controlled, randomized clinical trial for the treatment of pseudoxanthoma elasticum with oral pyrophosphate. Trials. 2025 Jan 29;26(1):30. doi: 10.1186/s13063-024-08666-w.

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

Sophie Bonnet

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, INVESTIGATOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 30, 2021

First Posted

May 3, 2021

Study Start

December 13, 2022

Primary Completion (Estimated)

December 13, 2026

Study Completion (Estimated)

September 1, 2027

Last Updated

May 17, 2024

Record last verified: 2024-05

Data Sharing

IPD Sharing
Will not share

Locations