Horizon Therapeutics' daxdilimab misses Phase II endpoint

Ireland-headquartered Horizon Therapeutics’ (Nasdaq: HZNP) shares were barely changed in morning trading today, despite the company announcing after hours on Friday that its Phase II clinical trial evaluating daxdilimab for the treatment of systemic lupus erythematosus (SLE) did not show a statistically-significant separation between daxdilimab and placebo on the primary endpoint.

Acquired along with its $3.05 billion buy of Viela Bio in 2021, daxdilimab is a cytotoxic ILT7 monoclonal antibody (Mab). ILT7 is a cell-surface protein displayed on plasmacytoid dendritic cells (pDCs). Under the deal, Horizon also acquired rights to Uplizna (inebilizumab-cdon), which had been approved by the US Food and Drug Administration in 2020.

“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 Thompson, executive vice president, research and development, Horizon.