UCB and Biogen Report Positive Phase 3 Results for Dapirolizumab Pegol in Lupus, Launching Second Study in 2024

The Phase 3 PHOENYCS GO study has yielded positive results, highlighting the potential of dapirolizumab pegol, a new anti-CD40L drug candidate, in treating moderate-to-severe systemic lupus erythematosus (SLE). UCB and Biogen, who are jointly developing this treatment, announced that the primary endpoint of the study was achieved, demonstrating significant clinical improvement in disease activity among participants.

The study involved a total of 321 participants and was conducted in a multicenter, randomized, double-blind, placebo-controlled, parallel-group format. Patients received either dapirolizumab pegol in addition to the standard of care (SOC) or a placebo alongside SOC. After 48 weeks, those treated with dapirolizumab pegol showed greater improvement in disease activity, assessed using the British Isles Lupus Assessment Group (BILAG)-based Composite Lupus Assessment (BICLA), compared to those receiving the placebo.

Key secondary endpoints also demonstrated clinical improvements in disease activity and flare reduction. The safety profile of dapirolizumab pegol was consistent with earlier studies and typical expectations for patients with SLE undergoing immunomodulatory treatment.

Dapirolizumab pegol is engineered to inhibit CD40L signaling, thereby reducing B cell activation, autoantibody production, and T cell and antigen-presenting cell activation. This mechanism addresses multiple inflammatory pathways involved in the pathogenesis of SLE. These promising results have led UCB and Biogen to initiate a second Phase 3 trial in 2024, named PHOENYCS FLY, while participants from the initial study will continue in a long-term open-label study.

SLE is a chronic, debilitating autoimmune disease that impacts various organ systems. It predominantly affects women, with 90% of patients being female, and symptoms usually emerge between the ages of 15-55. The disease can manifest in numerous ways, including rashes, arthritis, anemia, and neurological issues. Populations of African, Hispanic, Asian, and Native American descent often experience more severe disease and earlier onset. Pregnancy in women with SLE poses higher risks for both maternal and fetal health.

The success of dapirolizumab pegol could be a significant step in addressing the unmet medical needs of people living with SLE, offering a new therapeutic option where current treatments are limited. The positive outcomes from the PHOENYCS GO study reinforce the potential of this drug to deliver meaningful benefits to patients suffering from this serious and often life-altering disease.

Dr. Diana Gallagher from Biogen expressed optimism regarding the impact of targeting the CD40L pathway, which is essential in immune response, on reducing the SLE disease burden. The efficacy and safety results from the PHOENYCS GO study support further development of dapirolizumab pegol for SLE treatment.

Fiona du Monceau of UCB highlighted the importance of these findings, noting the high unmet medical need in lupus treatment and the disproportionate impact on women. UCB is committed to advancing this potentially differentiated treatment and appreciates the support and participation of patients, investigators, and the clinical community in their research efforts.

Detailed results from the PHOENYCS GO study are expected to be presented at an upcoming medical congress, providing further insights into the efficacy and safety of dapirolizumab pegol for treating moderate-to-severe SLE.