A phase 1, single-dose study of fresolimumab, an anti-TGF-β antibody, in treatment-resistant primary focal segmental glomerulosclerosis

Kidney Int. 2011 Jun;79(11):1236-43. doi: 10.1038/ki.2011.33. Epub 2011 Mar 2.


Primary focal segmental glomerulosclerosis (FSGS) is a disease with poor prognosis and high unmet therapeutic need. Here, we evaluated the safety and pharmacokinetics of single-dose infusions of fresolimumab, a human monoclonal antibody that inactivates all forms of transforming growth factor-β (TGF-β), in a phase I open-label, dose-ranging study. Patients with biopsy-confirmed, treatment-resistant, primary FSGS with a minimum estimated glomerular filtration rate (eGFR) of 25 ml/min per 1.73 m(2), and a urine protein to creatinine ratio over 1.8 mg/mg were eligible. All 16 patients completed the study in which each received one of four single-dose levels of fresolimumab (up to 4 mg/kg) and was followed for 112 days. Fresolimumab was well tolerated with pustular rash the only adverse event in two patients. One patient was diagnosed with a histologically confirmed primitive neuroectodermal tumor 2 years after fresolimumab treatment. Consistent with treatment-resistant FSGS, there was a slight decline in eGFR (median decline baseline to final of 5.85 ml/min per 1.73 m(2)). Proteinuria fluctuated during the study with the median decline from baseline to final in urine protein to creatinine ratio of 1.2 mg/mg with all three Black patients having a mean decline of 3.6 mg/mg. The half-life of fresolimumab was ∼14 days, and the mean dose-normalized Cmax and area under the curve were independent of dose. Thus, single-dose fresolimumab was well tolerated in patients with primary resistant FSGS. Additional evaluation in a larger dose-ranging study is necessary.

Publication types

  • Clinical Trial, Phase I
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Monoclonal / administration & dosage
  • Antibodies, Monoclonal / adverse effects
  • Antibodies, Monoclonal / pharmacokinetics
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Biomarkers / urine
  • Biopsy
  • Creatinine / urine
  • Dose-Response Relationship, Drug
  • Europe
  • Female
  • Glomerular Filtration Rate / drug effects
  • Glomerulosclerosis, Focal Segmental / drug therapy*
  • Glomerulosclerosis, Focal Segmental / immunology
  • Glomerulosclerosis, Focal Segmental / pathology
  • Glomerulosclerosis, Focal Segmental / physiopathology
  • Humans
  • Infusions, Parenteral
  • Kidney / drug effects*
  • Kidney / immunology
  • Kidney / pathology
  • Kidney / physiopathology
  • Male
  • Middle Aged
  • Proteinuria / drug therapy
  • Proteinuria / immunology
  • Transforming Growth Factor beta / antagonists & inhibitors*
  • Transforming Growth Factor beta / immunology
  • Treatment Outcome
  • United States
  • Young Adult


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Biomarkers
  • Transforming Growth Factor beta
  • fresolimumab
  • Creatinine