Recombinant human relaxin in the treatment of scleroderma. A randomized, double-blind, placebo-controlled trial

Ann Intern Med. 2000 Jun 6;132(11):871-9. doi: 10.7326/0003-4819-132-11-200006060-00004.


Background: Relaxin is a pregnancy-related hormone that has tissue remodeling and antifibrotic effects. Systemic sclerosis (scleroderma) is characterized by fibrosis of the skin, vasculature, and internal organs.

Objective: To assess the efficacy, safety, and dose-response effect of recombinant human relaxin in patients with scleroderma.

Design: Multicenter, parallel-group, randomized, double-blind, placebo-controlled trial.

Setting: Academic referral centers.

Patients: 68 patients who had had stable, diffuse scleroderma (moderate to severe) for less than 5 years.

Intervention: Recombinant human relaxin, 25 or 100 microg/kg of body weight per day, or placebo administered by continuous subcutaneous infusion over 24 weeks.

Measurements: Modified Rodnan skin score was the primary efficacy measure. Secondary measurements were pulmonary function, the Health Assessment Questionnaire, and other measures of scleroderma that reflected fibrosis.

Results: Patients who received 25 microg/kg of recombinant human relaxin per day had significantly lower skin scores than those who received placebo (mean change, -3.6 at 4 weeks [P = 0.021], -7.5 at 12 weeks [P < 0.001], and -8.7 at 24 weeks [P = 0.040]). Similar trends were noted in other outcome measures, including forced vital capacity, measures of oral aperture and hand extension, functional status, and global assessment. Patients who received 100 microg/kg of relaxin per day did not differ from those who received placebo. Drug-related adverse events included menometrorrhagia, reversible anemia, and complications of the subcutaneous drug administration system (site irritation and local infection).

Conclusions: Twenty-four weeks of recombinant human relaxin, 25 microg/kg per day, is associated with reduced skin thickening, improved mobility, and improved function in patients with moderate to severe diffuse scleroderma.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Analysis of Variance
  • Anemia / chemically induced
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Eruptions / etiology
  • Exanthema / chemically induced
  • Female
  • Humans
  • Male
  • Menorrhagia / chemically induced
  • Middle Aged
  • Placebos
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / adverse effects
  • Relaxin / administration & dosage*
  • Relaxin / adverse effects
  • Scleroderma, Systemic / drug therapy*
  • Scleroderma, Systemic / pathology


  • Placebos
  • Recombinant Proteins
  • Relaxin