Atacicept may be safe and effective for lowering disease activity and severity in patients with active systemic lupus erythematosus (SLE), according to results from a randomized placebo-controlled phase 2b study published in Arthritis & Rheumatology.
Investigators of the phase 2b ADDRESS II trial (ClinicalTrials.gov identifier: NCT01972568) evaluated the safety and efficacy outcomes associated with atacicept vs placebo in patients with active and autoantibody-positive SLE. Participants were randomly assigned to receive weekly doses of 75 mg atacicept (n=102), 150 mg atacicept (n=104), or placebo (n=100). SLE Responder Index (SRI)-4 and SRI-6 were used to assess SLE disease activity at 24 weeks.
At follow-up, a trend toward significant improvement in SRI-4 response rate was observed in study participants taking 75 mg atacicept (57.8%; adjusted odds ratio [OR], 1.78; P =.045) and 150 mg atacicept (53.8%; adjusted OR, 1.56; P =.121) compared with placebo (44.0%).
Patients with serologically active SLE exhibited greater SRI-4 response rates with atacicept at both 75 mg (62.1%; adjusted OR, 5.96; 95% CI, 1.85-19.15; P =.003) and 150 mg (61.5%; adjusted OR, 7.49; 95% CI, 2.12-26.44; P =.002) compared with controls. Rates of adverse events were similar in study participants receiving atacicept and in patients receiving placebo.
Few African American participants were included in the trial, which may reduce generalization of the findings. In addition, the short follow-up period (24 weeks) is not sufficient to assess the long-term safety and efficacy outcomes of atacicept.
Response differences between the groups were still significant in some instances, indicating “that atacicept treatment led to both clinical and serological improvements” in patients with active SLE.
Merrill JT, Wallace DJ, Wax S, et al. Efficacy and safety of atacicept in patients with systemic lupus erythematosus: results of a 24-week randomized, placebo-controlled, phase IIb study [published online October 26, 2017]. Arthritis Rheumatol. doi:10.1002/art.40360