FCX-013 Gene Therapy for Localized Scleroderma
FCX-013 Gene Therapy for Localized Scleroderma


At a Glance 

  • Chronic autoimmune disease characterized by thickening of the skin and connective tissue that can result in significant morbidity, including pain, restricted motion, disfigurement and developmental issues
  • Approximately 90,000 patients in the U.S. have severe localized scleroderma1
  • Current treatments – systemic or topical corticosteroids, UVA light therapy and physical therapy – only address symptoms
  • First gene therapy to offer the potential to address the underlying cause of localized scleroderma by regulating collagen accumulation at the site of the disease

About Localized Scleroderma

Localized scleroderma, of which linear is a subtype, is a chronic autoimmune skin disorder that manifests as excess production of extracellular matrix—specifically collagen—resulting in thickening of the skin and connective tissue. The localized areas of skin thickening may extend to underlying tissue and muscle in children which can impair growth and development. Lesions appearing across joints can be painful, impair motion and may be permanent.

Localized scleroderma is comprised of a number of forms or sub-types totaling slightly less than 200,000 people in the U.S.2 The U.S. population of patients who are considered to have severe localized scleroderma is estimated to be approximately 90,000.

Current treatments for localized scleroderma, including systemic or topical corticosteroids, UVA light therapy and physical therapy, only address the symptoms of the disorder.

LS clinical photo

About FCX-013

FCX-013 is an autologous fibroblast genetically-modified using lentivirus and encoded for matrix metalloproteinase 1 (MMP-1), a protein responsible for breaking down collagen. FCX-013 incorporates Intrexon’s proprietary RheoSwitch Therapeutic System® (RTS®), a biologic switch activated by an orally administered compound to control protein expression at the site of localized scleroderma lesions.

FCX-013 is designed to be injected under the skin at the location of the fibrotic lesions where the genetically-modified fibroblast cells will produce MMP-1 to break down excess collagen accumulation. With the FCX-013 therapy, the patient will take an oral compound to facilitate protein expression. Once the fibrosis is resolved, the patient will stop taking the oral compound which will control further MMP-1 production.

FCX-013 is currently in pre-clinical development for the treatment of moderate to severe localized scleroderma.

The U. S. Food and Drug Administration has granted Orphan Drug Designation to FCX-013 for the treatment of localized scleroderma, which includes linear scleroderma. In addition, FCX-013 has been granted Rare Pediatric Disease Designation for the treatment of moderate to severe localized scleroderma, including the linear subtype.

How Does FCX-013 Gene Therapy Work?

Dermal fibroblasts are collected from the patient, cultured and genetically modified to regulate collagen accumulation and then injected at the site of the localized disease.

Learn more

Explore Advocacy & Educational Resources

  1. Leitenberger, et. al. Distinct autoimmune syndromes in morphea: a case study of 245 adult and pediatric cases. Arch Dermatol. 2009 May; 145(5):545-550.
  2. The Scleroderma Foundation. What is Scleroderma? www.sclerodermra.org; accessed 10/09/2014.


Photo: © 2015 American College of Rheumatology.  Used with permission.