Pilot Study of Imatinib Mesylate to Treat Nephrogenic Systemic Fibrosis (GENESYF)

An Open Label Phase 2 Pilot Study to Determine the Safety, Efficacy and Tolerability of Gleevec (Imatinib Mesylate) in the Treatment of Nephrogenic Systemic Fibrosis

The purpose of this study is to determine the efficacy of imatinib mesylate in reducing cutaneous thickening and tethering in patients with nephrogenic systemic fibrosis (NSF). The study will also work to assess the safety and tolerability of imatinib mesylate in patients with chronic kidney disease and NSF.

Nephrogenic systemic fibrosis (NSF) is a recently described, extremely debilitating and painful condition that affects individuals with renal failure. Recent reports suggest an association between gadolinium exposure during magnetic resonance (MR) studies and the subsequent development of NSF in patients with chronic renal failure. NSF is characterized by rapidly progressive skin hardening, tethering and hyperpigmentation, predominantly on the extremities. Visceral involvement is rare. Skin biopsies of early NSF lesions demonstrate thickened collagen bundles, mucin deposition, angiogenesis and numerous dermal spindle cells that stain with antibodies to cluster of differentiation 34 (CD34) and procollagen. Cutaneous changes of NSF are present in up to 13% of individuals receiving hemodialysis. Among those patients with clinical evidence of NSF, the principle investigator of this protocol has recently reported that NSF is associated with increased early mortality at 24-months. There is no proven therapy for this devastating disorder. Anecdotal reports have shown modest improvement in joint mobility and decreased skin thickening with extracorporeal photopheresis and pentoxyphylline. Increased transforming growth factor (TGF)-beta1 messenger ribonucleic acid (mRNA) on immunostaining has been observed in skin, fascia and striated muscle. Imatinib mesylate, a tyrosine kinase inhibitor, prevents TGF-beta-induced stimulation of collagen and extracellular matrix protein synthesis as well as mRNA expression by normal fibroblasts. This observation led the principal investigator to evaluate imatinib mesylate 400 milligrams (mg) orally (p.o.) daily for 1 year in two participants with NSF. The result was significant softening of previously hardened skin with increased mobility of skin that previously had been tethered to the underlying fascia. After one month of imatinib mesylate, one of the two participants had a 20 degree reduction of his knee flexion contractures.

Imatinib mesylate 400 milligrams (mg) orally once daily for 4 months. Dosage was reduced to 200 mg if the participant developed gastrointestinal intolerance or alopecia.

400 mg p.o. daily for 4 months. Dosage was reduced to 200 mg if participants develop gastrointestinal intolerance or alopecia.

The modified Rodnan Skin Score is the accepted clinical measure of scleroderma skin activity. The investigator assessed the thickening of the skin using the modified Rodnan Skin Score through simple palpation on 17 different skin sites in the fingers, hands, forearms, arms, feet, legs, and thighs (bilaterally) and face, chest, and abdomen (singly). Skin thickness was assessed on a scale of 0 to 3; 0 representing normal skin and 3 being severe thickening. The sum of the individual scores can range from 0 (normal) to 51 (severe thickening in all 17 areas). Percentage change is calculated as the Month 4 Score - Baseline Score/Baseline Score * 100. A negative percentage change indicates improvement.

Inclusion Criteria: Age > 18 years Biopsy-proven NSF Ability to give consent Exclusion Criteria: Known sensitivity to imatinib mesylate or to any of its components Pregnant or lactating woman Bullous dermatologic disease Aspartate aminotransferase / alanine aminotransferase (AST/ALT) >3 x upper limit of normal Severe congestive heart failure [New York Heart Association (NYHA) Class III or IV] Patients who have received Gleevec in the past 12 months

Todd DJ, Kagan A, Chibnik LB, Kay J. Cutaneous changes of nephrogenic systemic fibrosis: predictor of early mortality and association with gadolinium exposure. Arthritis Rheum. 2007 Oct;56(10):3433-41. doi: 10.1002/art.22925.

Kay J, High WA. Imatinib mesylate treatment of nephrogenic systemic fibrosis. Arthritis Rheum. 2008 Aug;58(8):2543-8. doi: 10.1002/art.23696.

Kay J, Czirjak L. Gadolinium and systemic fibrosis: guilt by association. Ann Rheum Dis. 2010 Nov;69(11):1895-7. doi: 10.1136/ard.2010.134791. No abstract available.

Schmidt-Lauber C, Bossaller L, Abujudeh HH, Vladimer GI, Christ A, Fitzgerald KA, Latz E, Gravallese EM, Marshak-Rothstein A, Kay J. Gadolinium-based compounds induce NLRP3-dependent IL-1beta production and peritoneal inflammation. Ann Rheum Dis. 2015 Nov;74(11):2062-9. doi: 10.1136/annrheumdis-2013-204900. Epub 2014 Jun 9.

Todd DJ, Kay J. Gadolinium-Induced Fibrosis. Annu Rev Med. 2016;67:273-91. doi: 10.1146/annurev-med-063014-124936.