The study will take place across 238 sites and aims to enroll 474 adults.
The Phase 2 Lilac study for litifilimab was published in the New England Journal of Medicine in July, noting that treatment with litifilimab was superior to placebo with regard to a measure of skin disease activity over 16 weeks. The Phase 2/3 trial will asses the efficacy and safety over a longer period.
mAbs against lupus
CLE, a type of lupus, is a chronic autoimmune skin disease that can ultimately result in scarring, alopecia and dyspigmentation.
An estimated 90% of cases are in women, with most beginning to see symptoms between the ages of 15-40. The disease disproportionately impacts diverse ethno-racial groups, including African American, Asian, American Indian/Alaskan Native and Hispanic/Latino communities. There is currently no cure for lupus.
Litifilimab (known as BIIB059), discovered and developed in-house by Biogen scientists, is a humanized IgG1 monoclonal antibody (mAb) targeting BDCA2. It is already in Phase 3 trials for the potential treatment of systemic lupus erythematosus (SLE) and now enter the ‘Amethyst’ Phase 2/3 trials for cutaneous lupus erythematosus (CLE).
Amethyst is a two-part, Phase 2/3, multicenter, double-blind, placebo controlled, randomized study to evaluate the efficacy and safety of litifilimab compared to placebo. The Phase 2 and Phase 3 parts of the study will each be 52 weeks in duration. Participants will be randomized to receive subcutaneous treatment with litifilimab or placebo every four weeks for 20 weeks with an additional loading dose at week 2. All participants will receive litifilimab during the 28-week extended treatment period from Weeks 24 to 48. The primary endpoint will assess the effect of litifilimab on skin disease activity, compared to placebo.
“CLE is more severe and frequent among African American and Hispanic/Latino patients, compared to white patients, which is why for AMETHYST we have set enrollment targets with the objective of appropriate representation for these traditionally underrepresented groups,” said Priya Singhal, M.D., M.P.H., Head of Global Safety and Regulatory Sciences and Interim Head of R&D at Biogen. “We are excited to advance litifilimab into what will be one of the largest clinical studies in CLE, where there are currently insufficient treatment options that address the needs of people living with this disease.”
A second lupus therapy from Biogen, Dapirolizumab pegol, is being developed in collaboration with UCB for systemic lupus erythematosus (SLE) and is in Phase 3 trials.