Treatment of pemphigus vulgaris and foliaceus with efgartigimod, a neonatal Fc receptor inhibitor: a phase II multicentre, open-label feasibility trial

Br J Dermatol. 2022 Mar;186(3):429-439. doi: 10.1111/bjd.20782. Epub 2021 Nov 28.

Abstract

Background: Pemphigus vulgaris and pemphigus foliaceus are potentially life-threatening autoimmune disorders triggered by IgG autoantibodies against mucosal and epidermal desmogleins. There is an unmet need for fast-acting drugs that enable patients to achieve early sustained remission with reduced corticosteroid reliance.

Objectives: To investigate efgartigimod, an engineered Fc fragment that inhibits the activity of the neonatal Fc receptor, thereby reducing serum IgG levels, for treating pemphigus.

Methods: Thirty-four patients with mild-to-moderate pemphigus vulgaris or foliaceus were enrolled in an open-label phase II adaptive trial. In sequential cohorts, efgartigimod was dosed at 10 or 25 mg kg-1 intravenously with various dosing frequencies, as monotherapy or as add-on therapy to low-dose oral prednisone. Safety endpoints comprised the primary outcome. The study is registered at ClinicalTrials.gov (identifier NCT03334058).

Results: Adverse events were mostly mild and were reported by 16 of 19 (84%) patients receiving efgartigimod 10 mg kg-1 and 13 of 15 (87%) patients receiving 25 mg kg-1 , with similar adverse event profiles between dose groups. A major decrease in serum total IgG and anti-desmoglein autoantibodies was observed and correlated with improved Pemphigus Disease Area Index scores. Efgartigimod, as monotherapy or combined with prednisone, demonstrated early disease control in 28 of 31 (90%) patients after a median of 17 days. Optimized, prolonged treatment with efgartigimod in combination with a median dose of prednisone 0·26 mg kg-1 per day (range 0·06-0·48) led to complete clinical remission in 14 of 22 (64%) patients within 2-41 weeks.

Conclusions: Efgartigimod was well tolerated and exhibited an early effect on disease activity and outcome parameters, providing support for further evaluation as a therapy for pemphigus.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal, Humanized* / adverse effects
  • Autoantibodies
  • Desmoglein 1
  • Feasibility Studies
  • Histocompatibility Antigens Class I
  • Humans
  • Immunoglobulin G
  • Infant, Newborn
  • Pemphigus* / drug therapy
  • Prednisone / administration & dosage
  • Receptors, Fc

Substances

  • Antibodies, Monoclonal, Humanized
  • Autoantibodies
  • Desmoglein 1
  • Histocompatibility Antigens Class I
  • Immunoglobulin G
  • Receptors, Fc
  • efgartigimod alfa
  • Fc receptor, neonatal
  • Prednisone

Associated data

  • ClinicalTrials.gov/NCT03334058