Thousand Oaks, California, U.S., September 22, 2026
Amgen has announced positive topline results from the pivotal Phase 3 OASIZ 301 study evaluating dazodalibep in adults with moderate-to-severe systemic Sjögren’s disease. The study met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in systemic disease activity at Week 48, measured using the EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI). Amgen reported that improvements in systemic disease activity were observed as early as Week 4 and were sustained through Week 48. The results represent an important clinical development milestone for dazodalibep, an investigational CD40L antagonist fusion protein being studied as a potential treatment for patients with significant systemic manifestations of Sjögren’s disease.
OASIZ 301 Meets Its Primary Endpoint
The randomized, double-blind, placebo-controlled OASIZ 301 Phase 3 study enrolled approximately 621 adults with Sjögren’s disease and moderate-to-severe systemic disease activity, defined by an ESSDAI score of at least 5. The primary endpoint evaluated the change from baseline in ESSDAI score at Week 48, while key secondary assessments included dryness, tender and swollen joints, fatigue, and ESSDAI response. Amgen reported that dazodalibep achieved the primary endpoint with a statistically significant and clinically meaningful improvement compared with placebo. The company also highlighted the rapid onset of improvement, with changes in ESSDAI becoming apparent by Week 4 and continuing through the 48-week assessment.
The findings are relevant because Sjögren’s disease is a systemic autoimmune disorder that can affect multiple organs in addition to causing characteristic dryness. People living with the disease may experience fatigue, chronic pain, neuropathy, arthritis, and organ involvement, while the condition is also associated with an increased risk of lymphoma. Amgen noted that there are currently no FDA-approved medicines specifically for Sjögren’s disease, leaving substantial unmet medical need for therapies capable of addressing systemic disease activity. The OASIZ 301 findings therefore provide clinical evidence supporting continued evaluation of dazodalibep in this patient population.
Dazodalibep Targets CD40L-Mediated Immune Activation
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Dazodalibep is being developed as a potential first-in-class CD40 ligand (CD40L) antagonist. The fusion protein is designed to interfere with interactions between T cells, B cells, and other antigen-presenting cells, thereby targeting an immune signaling pathway involved in autoimmune disease. Amgen is investigating the therapy in two distinct Sjögren’s disease populations: people with moderate-to-severe systemic disease and people experiencing a high symptom burden despite having low systemic disease activity. The approach is intended to address the underlying immune activation associated with Sjögren’s disease rather than focusing solely on individual symptoms.
The safety findings from OASIZ 301 were also part of the topline announcement. The most common adverse events occurring at a frequency of at least 5% and at a higher rate with dazodalibep than placebo included nasopharyngitis, urinary tract infection, hypertension, and infusion-related reactions. These events were generally mild to moderate, according to Amgen. Treatment discontinuations resulting from adverse events occurred at a low rate and were balanced between treatment groups. The company also reported no imbalance in thromboembolic events or opportunistic infections across the treatment arms. Detailed study results are expected to be presented at an upcoming medical meeting.
Amgen Advances Broader Sjögren’s Disease Program
The positive OASIZ 301 results form part of a broader clinical development program evaluating dazodalibep across different manifestations of Sjögren’s disease. Amgen is also conducting the Phase 3 OASIZ 303 study, which evaluates dazodalibep in patients with moderate-to-severe symptoms and low systemic disease activity. That study is expected to complete in the fourth quarter of 2026. In addition, the company is conducting OASIZ 304, an open-label long-term extension study designed to assess the long-term safety and tolerability of dazodalibep in eligible participants from OASIZ 301 and OASIZ 303. For patients with Sjögren’s disease, the development of treatments capable of addressing systemic disease activity remains an important area of pharmaceutical research. The Phase 3 OASIZ 301 results provide new clinical evidence for dazodalibep and support its continued investigation. However, dazodalibep remains an investigational therapy, and the topline findings do not establish regulatory approval or future efficacy. Amgen plans to provide more detailed clinical data at a future medical meeting as development of the program continues.
Source: Amgen press release
