The Company continues to assess the full dataset; daxdilimab trials in alopecia areata, discoid lupus erythematosus and lupus nephritis ongoing –

DUBLIN, Ireland I July 21, 2023 I Horizon Therapeutics plc (Nasdaq: HZNP) today announced that its Phase 2 clinical trial evaluating daxdilimab for the treatment of SLE did not show a statistically significant separation between daxdilimab and placebo on the primary endpoint, which was the proportion of patients to achieve a British Isles Lupus Assessment Group (BILAG) 2004 Index-based Combined Lupus Assessment (BICLA) response and an oral glucocorticoid (OGC) dose of ≤7.5 mg/day (prednisone equivalent), which represented a reduction from the Baseline OGC dose at 48 weeks. BICLA is a composite measure indicating low SLE disease activity. Numerical differences were seen in other endpoints. No safety concerns were reported.

“While we are disappointed that the trial did not meet its primary endpoint, we will continue to work with investigators to assess these data to determine next steps for our SLE clinical program,” said Elizabeth H.Z. Thompson, Ph.D., executive vice president, research and development, Horizon. “I would like to thank the patients and investigators for their participation in the trial.”

About the Daxdilimab Phase 2 Clinical Trial in Systemic Lupus Erythematosus

The Phase 2 study enrolled patients with moderate-to-severely active SLE. A total of 214 patients were randomized into three parallel arms: daxdilimab given subcutaneously 200 mg every 4 weeks, 200 mg every 12 weeks or placebo every 4 weeks. Additional trial endpoints included the Systemic Lupus Erythematosus Responder Index of 4 (SRI-4), other measures of lupus disease activity and reduction in OGC.

About Daxdilimab

Daxdilimab is an anti-ILT7 human monoclonal antibody that depletes certain dendritic cells. Depleting these cells may interrupt the cycle of inflammation that causes tissue damage in a variety of autoimmune conditions. Horizon is also investigating daxdilimab in alopecia areata, discoid lupus erythematosus and lupus nephritis and plans to investigate it in dermatomyositis or anti-synthetase inflammatory myositis.

About Horizon

Horizon is a global biotechnology company focused on the discovery, development and commercialization of medicines that address critical needs for people impacted by rare, autoimmune and severe inflammatory diseases. Our pipeline is purposeful: We apply scientific expertise and courage to bring clinically meaningful therapies to patients. We believe science and compassion must work together to transform lives. For more information on how we go to incredible lengths to impact lives, visit and follow us on Twitter, LinkedIn, Instagram and Facebook.


  1. Furie RA, Petri MA, Wallace DJ, et al. Novel evidence-based systemic lupus erythematosus responder index. Arthritis Rheum. 2009;61(9):1143-1151.

SOURCE: Horizon Therapeutics