Horizon Therapeutics has announced the enrolment of the first patient in a Phase II clinical trial of its antibody daxdilimab for treating discoid lupus erythematosus (DLE).

The placebo-controlled, randomised trial has been designed to assess the company’s development-stage medicine daxdilimab for individuals with moderate-to-severe primary DLE, a rare, chronic, inflammatory skin condition.

For the Phase II trial, Horizon expects to enrol nearly 100 subjects.

The mean change in Cutaneous Lupus Erythematosus Disease Area and Severity Index-Activity (CLASI-A) score from baseline to week 24 is the study’s primary endpoint.

Activity in inflammatory lupus skin disease can be measured using this endpoint that ranges from zero to 70. Higher scores suggest a more active and skin damaging disease.

The trial’s key inclusion criteria includes a diagnosis of moderate-to-severe DLE for over six months before screening, supported by a biopsy and/or a clinical feature score of ≥7 on the DLE Classification Criteria (DLECC) scale.

This score enables specific validation and classification of DLE in several clinical variables including disease location, atrophic scarring on the body, and dyspigmentation.

Horizon Therapeutics clinical development senior vice-president Theresa Podrebarac said: “Plasmacytoid dendritic cells, or pDCs, are reported to be abundant in DLE skin lesions while interferon levels are elevated and daxdilimab has been shown to deplete pDCs.

“Daxdilimab is also being investigated in other autoimmune conditions that are driven by high levels of interferon including alopecia areata, dermatomyositis, lupus nephritis, and systemic lupus erythematosus.”

Daxdilimab is a potentially first-in-class, anti-ILT7 human monoclonal antibody that depletes certain dendritic cells.

Last month, Horizon dosed the first participant in a Phase I trial of HZN-457 to treat gout.