[{"id":"ep1","name":"BICLA response at Week 48","type":"PRIMARY","unit":"%","results":[{"n":208,"arm":"DZP + SOC","value":49.5,"detail":"103/208 responders"},{"n":107,"arm":"Placebo + SOC","value":34.6,"detail":"37/107 responders"},{"ci_95":"3.3 to 25.8","p_value":0.011,"comparison":"Difference: 14.6%"}],"timepoint":"Week 48","description":"British Isles Lupus Assessment Group-based Composite Lupus Assessment. Measures whether lupus disease activity improved across all organ systems without worsening in any. Think of it as a report card that checks every part of the body affected by lupus - you pass only if everything improved or stayed the same, nothing got worse."}]

Generally well-tolerated. TEAEs slightly higher in DZP arm (82.6% vs 75.0%) but serious TEAEs actually lower (9.9% vs 14.8%). Key safety signal: opportunistic infections (2.8% vs 0.9%) and 1 thromboembolic event (MI) in DZP arm. 1 death (gangrene-related sepsis) in DZP arm. No pattern of increased thromboembolic risk vs historical anti-CD40L concerns. Discontinuation due to AEs low and similar (4.7% vs 3.7%).

POSITIVE RESULT with a major nuance: PRIMARY: Met. BICLA Wk48 49.5% vs 34.6%, delta 14.6%, p=0.011. Clean win. THE CATCH: BICLA Wk24 (first key secondary) FAILED (46.6% vs 38.3%, p=0.18). This breaks the hierarchical testing chain, so ALL other endpoints are nominal only. Regulators may accept this since primary was pre-specified at Wk48, but it is a discussion point. INVESTMENT IMPLICATIONS: - UCB: Key pipeline asset. ~$1-2B peak sales (50% to UCB = $0.5-1B) - BIIB: Modest impact given larger portfolio, but validates lupus franchise - Needs PHOENYCS FLY confirmatory data for filing confidence - Competitive: belimumab (GSK) and anifrolumab (AZN) are established. DZP is novel MOA but IV-only. OPEN QUESTIONS: 1. Will FDA require PHOENYCS FLY before filing, or can they file on GO alone? 2. SC formulation in development? IV q4w is less convenient than SC options 3. Long-term safety of CD40L blockade? Only 1 year Phase 3 data Sources: ACR 2024, EULAR 2025, Biogen/UCB joint press releases

Anti-CD40L has been an SLE target for 20+ years but earlier full antibodies (ruplizumab) caused blood clots. DZP is an Fc-free PEGylated Fab fragment designed to block CD40L without the clotting risk - like removing the part of the key that jams the lock.