Magnesium Supplements In The Treatment Of Pseudoxanthoma Elasticum (PXE)

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Mark Lebwohl, Mount Sinai School of Medicine Identifier:
First received: February 1, 2012
Last updated: December 30, 2013
Last verified: December 2013

The purpose of this study is to evaluate the effectiveness of magnesium oxide supplements on the reversal of calcium deposits in the skin, and the yellow bumps and folds of skin in subjects with pseudoxanthoma elasticum (PXE). Magnesium oxide is a dietary supplement that has been shown in some research to reduce these calcium deposits. This study consists of two parts. The first part is a year-long, double-blind, placebo-controlled study. Part two is an open-label, year-long study. In Part 1, qualified subjects will be randomized to receive either magnesium oxide supplements or placebo, in a 1:1 ratio for the first 12 months. The starting dose will be 1000 mg daily, and depending on tolerability, doses may be decreased. Baseline evaluations will be comprised of: blood tests; clinical evaluations; skin biopsy; eye examination; bone density test; and photography of skin lesions. Subjects will be evaluated at week 2, week 6, month 3, and then every 3 months during the first year. Upon completion of the first year, barring any safety concerns, all subjects will be administered magnesium oxide supplements for up to one additional year. Subjects will undergo the same evaluations/ procedures every 3 months. We hypothesize that the magnesium oxide will cause a reduction in calcifications in the subject's soft tissue/skin. Funding Source - FDA OOPD.

Condition Intervention Phase
Pseudoxanthoma Elasticum
Drug: Magnesium Oxide
Drug: Placebo
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Magnesium Supplements In The Treatment Of Pseudoxanthoma Elasticum (PXE)

Resource links provided by NLM:

Further study details as provided by Mount Sinai School of Medicine:

Primary Outcome Measures:
  • Reversal of elastic fiber calcification [ Time Frame: Baseline, Month 12, and Month 24 ] [ Designated as safety issue: No ]
    A blinded dermatopathologist will grade skin biopsies on the density of Von Kossa staining. We will assess changes in the amount of calcification of elastic fibers by assessing von Kossa staining per unit area of dermis

Secondary Outcome Measures:
  • Reversal of clinical skin lesions [ Time Frame: Screening, Months 6, 12, 18 and 24 ] [ Designated as safety issue: No ]
    Changes in skin skin lesions observed through investigator evaluations and clinical photographs

  • Rate of disease progression [ Time Frame: Baseline, Month 12 and Month 24 ] [ Designated as safety issue: No ]
    Changes observed through ophthalmologic examinations

  • Rate of disease progression [ Time Frame: Month 12 ] [ Designated as safety issue: No ]
    Observed through ophthalmologic examinations

  • Rate of disease progression [ Time Frame: Month 24 ] [ Designated as safety issue: No ]
    Observed through ophthalmologic examinations

Enrollment: 44
Study Start Date: August 2012
Estimated Study Completion Date: July 2015
Estimated Primary Completion Date: April 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Magnesium oxide
1000 mg (one 500 mg capsule two times daily) of magnesium oxide
Drug: Magnesium Oxide
1000 mg (one 500 mg capsule two times daily) of magnesium oxide.
Placebo Comparator: Placebo
1000 mg (one 500 mg capsule two times daily) of placebo.
Drug: Placebo
1000 mg (one 500 mg capsule two times daily) of placebo.

  Show Detailed Description


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male or female subject at least 18 years of age
  • If female, the subject is not pregnant or nursing
  • If female of child bearing potential, the subject has a negative urine pregnancy test at the first visit, and agrees to use an approved method of contraception (hormonal contraceptives [birth control pills, implants [Norplant] or injections [DepoProvera]); intrauterine device (IUD); two forms of barrier methods [condoms and diaphragm]; or abstinence (no sexual activity) throughout the entire study
  • Biopsy confirmed diagnosis of pseudoxanthoma elasticum (documenting some calcification of elastic fibers)
  • Subject has a clinical disease severity grade of at least "1" (Poorly defined, barely visible macules) at screening.
  • Normal kidney function tests

Exclusion Criteria:

  • Any subject who is pregnant or becomes pregnant during the study
  • Subjects with a serum creatinine greater than 1.6 mg/dL
  • Subjects with hypermagnesemia, hypokalemia, or idiopathic hypercalciuria
  • Subjects with kidney disease or renal tubular defects (eg. Fanconi's syndrome), or on dialysis
  • Subjects with hypothyroidism or hypoparathyroidism or primary hyperparathyroidism
  • Subjects with acute gout
  • Subjects with malabsorption, or osteomalacia
  • Subjects on diuretics, magnesium containing antacids, or anabolic steroids
  • Subjects with Cushing's syndrome
  • Subjects receiving lithium and those with significant psychiatric disorders that would likely interfere with participation in this study
  • Subjects taking anti-seizures medications and anti-arrhythmics medications
  • Subjects on tetracycline or metronidazole and ace inhibitors
  • Subjects taking cyclosporine or calcineurin inhibitors
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01525875

United States, New York
Icahn School of Medicine at Mount Sinai
New York, New York, United States, 10029
Sponsors and Collaborators
Mark Lebwohl
Principal Investigator: Mark Lebwohl, MD Mount Sinai School of Medicine
  More Information

Blum R, Phelps R, Fuchs W, Lebwohl M. Oral Phosphate Binders in the Treatment of Pseudoxanthoma Elasticum. 64th Annual Meeting American Academy of Dermatology March 3-7, 2006, San Francisco, CA. Manuscript in press J Amer Acad Dermatol 2011

Responsible Party: Mark Lebwohl, Principal Investigator, Mount Sinai School of Medicine Identifier: NCT01525875     History of Changes
Other Study ID Numbers: GCO 09-1157, FD-R-0003903, Funding Source - FDA OOPD
Study First Received: February 1, 2012
Last Updated: December 30, 2013
Health Authority: United States: Food and Drug Administration
United States: Institutional Review Board

Keywords provided by Mount Sinai School of Medicine:
pseudoxanthoma elasticum

Additional relevant MeSH terms:
Pseudoxanthoma Elasticum
Hemostatic Disorders
Vascular Diseases
Cardiovascular Diseases
Hemorrhagic Disorders
Hematologic Diseases
Skin Abnormalities
Congenital Abnormalities
Skin Diseases, Genetic
Genetic Diseases, Inborn
Connective Tissue Diseases
Skin Diseases
Magnesium Oxide
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions processed this record on August 21, 2014