Biogen, UCB Take A Leap In Lupus With Promising Phase 3 Results

UCB SA UCBJY UCBJF (Euronext Brussels: UCB) and Biogen Inc. BIIB on Thursday presented additional detailed results from the Phase 3 PHOENYCS GO study evaluating dapirolizumab pegol (DZP).

The companies released topline results in September 2024.

UCB and Biogen unveiled detailed results from their Phase 3 PHOENYCS GO trial this week at EULAR 2025, showing that their investigational lupus drug dapirolizumab pegol (DZP) significantly improved disease activity and fatigue in patients with systemic lupus erythematosus (SLE).

The data bolster Biogen's presence in immunology as the company also sharpens its focus on neuroscience, announcing a $46 million collaboration with City Therapeutics to develop RNAi therapies targeting central nervous system disorders.

Together, the trial results and new partnership underscore Biogen's dual strategy: strengthening late-stage autoimmune assets while replenishing its early pipeline with next-gen CNS innovations.

Also Read: Biogen Beats Q1 Earnings Expectations As Two Newcomer Drug Sales Spike, Avoids Tariff Impact

These results were presented at EULAR 2025, the European Alliance of Associations for Rheumatology’s annual meeting.

DZP’s safety and efficacy in SLE have not been established, and no regulatory authority worldwide has approved its use in SLE.

In an analysis of the impact of DZP on patient-reported fatigue, individuals receiving DZP in addition to standard of care (SOC) treatment demonstrated improvements across two fatigue measurements:

In an additional analysis, improvements were seen on measures of low disease activity, as measured by Low Lupus Disease Activity State (LLDAS) and disease remission.

At Week 48, the percentage of participants achieving low disease activity in the DZP group was twice that of the SOC-only group (40.9% and 19.6%, respectively).
23.6% of participants receiving DZP plus SOC achieved low disease activity in ≥50% of visits through 48 weeks compared with 15.9% receiving SOC alone.
A higher proportion of those receiving DZP (19.2%) versus SOC alone (8.4%) also achieved disease remission at Week 48.

Participants from the PHOENYCS GO study will continue to be followed in a long-term open-label study. A second Phase 3 trial of dapirolizumab pegol, PHOENYCS FLY, is ongoing.

In May, Biogen and City Therapeutics, Inc., a privately held biopharmaceutical company, announced a strategic collaboration to develop select novel RNAi therapies.

The collaboration will initially focus on a single target that mediates key central nervous system diseases. Biogen will be responsible for IND-enabling studies and global clinical development along with any regulatory submissions and all activities related to commercialization.

City Therapeutics will receive $46 million in payments, including a $16 million upfront payment and an investment of $30 million in exchange for a City Therapeutics convertible note, representing a minority equity interest in the company if converted.

Biogen will record the upfront payment as an Acquired In-Process Research and Development expense in the second quarter of 2025.

Should the initial program achieve certain development and commercial milestones, City Therapeutics can receive up to approximately $1 billion in potential milestone payments plus tiered royalties in the high single-digit to low double-digit range based on net sales.

Biogen will have the option to select one additional target in the collaboration, subject to an additional payment and availability of the target.

Price Action: BIIB stock is up 0.74% at $134.05 at the last check on Thursday.

Read Next: