EMD Serono‘s atacicept can effectively reduce disease activity among lupus patients with high disease activity at baseline, according to new data from the Phase 2b ADDRESS II trial.
The study, “Attainment of Low Disease Activity By Patients with Systemic Lupus Erythematosus Starting with High Disease Activity in a 24-Week, Randomized, Placebo-Controlled, Phase IIb Study of Atacicept (ADDRESS II),” was presented during the 2017 ACR/ARHP Annual Meeting in San Diego.
Atacicept is a fusion protein that blocks the activity of the signaling proteins B lymphocyte stimulator (BLyS) and A proliferation-inducing ligand (APRIL). Preclinical studies showed that atacicept could regulate the maturation of immune B-cells and inhibit the production of autoantibodies that trigger lupus.
Results from the Phase 2b ADDRESS II trial (NCT01972568) recently appeared in the journal Arthritis and Rheumatology. Atacicept was found to be safe and well tolerated by lupus patients, while showing potential to regulate autoimmune responses.
The trial enrolled 306 lupus patients who randomly received either 75 mg or 150 mg of atacicept, or a placebo, once a week. After 24 weeks of treatment, 57.8 percent of patients receiving 75 mg atacicept and 53.8 percent of patients receiving 150 mg atacicept had a significant reduction in disease activity from baseline. Of the placebo group, 44 percent saw significant reduction in disease activity. The treatment also reduced the levels of autoantibodies.
This latest analysis, focusing only on the 158 patients with high disease activity at baseline, shows that atacicept was also effective in this group.
Results showed that, irrespective of their treatment, 23.4 percent of patients achieved low disease activity, as determined by a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of 2 or lower. In addition, 12 percent had a SLEDAI-2K score of 2 or lower and required a prednisone dose of 7.5 mg/day or lower. An additional 42.4 percent achieved a SLEDAI-2K of 4 or lower without major organ activity, prednisone dose of 7.5 mg/day or lower, and stable maintenance dose of immunosuppressants. Patients in these three groups were all deemed as having low disease activity.
Interestingly, patients who achieved low disease activity were mostly those with greater responses (SLE responder index-6), and receiving the higher atacicept dose. Patients who received 150 mg of atacicept were three to five times more likely to achieve low disease activity as were patients on placebo.
The findings continue to support the potential of atacicept as a treatment for lupus patients, including those with high disease activity. Nonetheless, additional studies testing atacicept are still needed, researchers said.