Recommendations for the use of CLASI as an outcome measure in cutaneous lupus erythematosus clinical trials

Cutaneous lupus erythematosus (CLE) is an autoimmune skin condition associated with a considerable treatment burden and diminished quality of life. The absence of a consensus outcome measure to evaluate therapeutic response has posed a challenge to CLE drug development. The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) was developed in response to this need, incorporating morphological components including erythema, scale, dyspigmentation and scarring, to reflect disease activity and damage. Numerous studies have demonstrated the utility of CLASI in capturing relevant aspects of disease from clinician- and patient-based perspectives; however, no regulatory precedent for use of clinical trial data employing CLASI to evaluate treatment response in CLE exists. Thus, the Lupus Accelerating Breakthroughs Consortium commissioned a working group of members from industry, academia, the US Food and Drug Administration (FDA) and CLE patient advocates to address the potential knowledge gaps with CLASI through evidence-based research. Upon reviewing and submitting these data to the FDA, the working group reached alignment that CLASI is a suitable outcome measure for CLE clinical trials, enabling a clearer regulatory path for clinical drug development. The group recognizes the need for additional information to assess what degree of change in CLASI captures clinically meaningful improvement.