Biogen and UCB present positive Phase 3 PHOENYCS GO data for lupus candidate dapirolizumab pegol

Biogen (NASDAQ:BIIB) and UCB have announced the release of positive results from the Phase 3 PHOENYCS GO clinical trial evaluating dapirolizumab pegol (DZP), an investigational treatment for systemic lupus erythematosus (SLE).

The data was presented this week at the European Alliance of Associations for Rheumatology (EULAR) 2026 Congress.

The trial evaluated the efficacy and safety of DZP in combination with the standard of care compared to the standard of care alone.

Patients treated with the dapirolizumab pegol regimen demonstrated sustained disease control, particularly during the critical phase of glucocorticoid tapering.

Furthermore, the therapy was associated with a notable reduction in disease flare rates and demonstrated improvements across multiple key immunological markers.

The safety analysis through Week 48 indicated a generally favorable profile, consistent with previous study findings.

The results reinforce the potential of dapirolizumab pegol—a PEGylated anti-CD40L monoclonal antibody—to serve as an effective therapeutic option for patients struggling to manage disease activity while attempting to reduce their dependence on corticosteroids.

Biogen and UCB intend to continue the evaluation of the PHOENYCS GO dataset to determine the next steps for regulatory submission.

Lupus remains a complex and challenging condition to treat, and these findings represent a significant milestone for the dapirolizumab pegol development program as the companies seek to offer a novel mechanism of action for patients with SLE.