Biogen has started dosing patients in a late-stage study evaluating its potential systemic lupus erythematosus (SLE) treatment BIIB059.
Biogen has initiated the phase 3 study based on results from the phase 2 LILAC study. In this mid-stage study, BIIBO59 met the primary endpoint of demonstrating statistically significant reduction of disease activity in patients in patients with SLE.
The phase 3 TOPAZ-1 study is set to evaluate the efficacy and safety of BIIB059 compared to placebo for the treatment of participants with active SLE.
BIIB059 is a potentially first-in-class humanised IgG1 monoclonal antibody (mAb), designed to target blood dendritic cell antigen 2 (BDCA2) – a receptor that is exclusively expressed on a plasmacytoid dendritic cells (pDCs).
This receptor has been previously shown to reduce inflammatory cytokine production from pDCs, including type-I IFN (IFN-I) – inflammatory mediators are believed to play a major role in the pathogenesis of lupus.
The TOPAZ-1 study is aiming to enrol 540 adults with active SLE across approximately 135 sites across the globe.
Participants in the study will be randomised to receive either subcutaneous treatment with BIIB059 at one of two doses or placebo every four weeks, with an additional dose at week 2, alongside their existing lupus therapy.
Primarily, the trial will aim to demonstrate reduction in disease activity as measured with the primary endpoint – the proportion of participants who achieve an SLE Responder Index-4 (SRI-4) response at week 52.
The study’s key secondary endpoints include the proportion of patients achieving SRI-4 response at week 24, oral corticosteroid use, organ-specific disease activity and flare rates.
“We look forward to working with the lupus community as we advance the clinical development of BIIB059 with the hope of bringing a meaningful new treatment option to people living with systemic and cutaneous lupus,” said Nathalie Franchimont, head of the multiple sclerosis and immunology development unit at Biogen.
“Additionally, we are reinforcing Biogen’s commitment to the inclusion of underrepresented groups in our clinical trials. We have set enrolment targets that reflect the prevalence of SLE in African-American and Hispanic/Latinx communities with the aim to achieve appropriate representation in the TOPAZ-1 study,” she added.
In addition to BIIB059, Biogen also has another investigational lupus asset – dapirolizumab pegol – which it is developing in collaboration with UCB. This candidate began a phase 3 clinical trial in 2020 and targets the CD40L ligand, rather than the BDCA2 receptor.