Amgen's Dazodalibep Achieves Phase 3 Success in Sjögren's Disease

Key points

• Amgen's dazodalibep met the primary endpoint in the OASIZ 301 Phase 3 study, demonstrating statistically significant and clinically meaningful improvement in the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) at Week 48.
• The trial enrolled approximately 621 to 651 patients with moderate-to-severe systemic Sjögren's disease, a condition where the immune system attacks tear and salivary glands, often leading to dryness, fatigue, and organ involvement.
• Dazodalibep is a CD40 ligand antagonist fusion protein that disrupts interactions between T cells, B cells, and other antigen-presenting cells; improvements were observed as early as Week 4 and sustained through Week 48.
• Common side effects included nasopharyngitis, urinary tract infection, hypertension, and infusion-related reactions, which were generally mild to moderate; discontinuation rates due to adverse events were low and balanced across treatment groups.
• A second Phase 3 trial, OASIZ 303, is focused on patients with high symptom burden but low systemic disease activity and is expected to complete in Q4 2026; the FDA likely requires two positive Phase 3 readouts for approval.
• This success contrasts with recent failures in the Sjögren's pipeline, including Amgen's discontinuation of adezkibart in May 2026 and similar program drops by Novartis and Sanofi, though Novartis continues to develop ianalumab.

Background

Sjögren's disease is the second most common autoimmune rheumatic disease but remains widely underrecognized, with no FDA-approved disease-modifying therapies currently available. Symptoms range from dry eyes and mouth to profound fatigue, chronic pain, and increased lymphoma risk. Amgen acquired Horizon Therapeutics in 2023 for $27.8 billion, which centered on approved products like Uplizna and Krystexxa. Dazodalibep, however, was not part of the Horizon acquisition but was obtained through Amgen's 2021 $3 billion acquisition of AstraZeneca spinout Viela Bio. The broader biopharma industry has struggled with Sjögren's treatments recently, with multiple companies dropping programs after failed trials or futility analyses.

How outlets are covering it

Fierce Biotech and PR Newswire both highlight the positive Phase 3 results for dazodalibep, emphasizing the lack of approved treatments for Sjögren's and the potential for a new differentiated option. Fierce Biotech notes that this success adds validation to the CD40L mechanism of action and could have positive read-through to the ongoing OASIZ 303 study, though analysts from William Blair caution that the two trials enrolled distinct patient populations. PR Newswire provides additional detail on the safety profile, noting no imbalance in thromboembolic events or opportunistic infections, and includes quotes from the Sjögren's Foundation welcoming the progress. Endpoints News mentions the Phase 3 win but does not provide detailed analysis in the accessible portion. All sources agree on the significance of the result for Amgen's pipeline, which has faced recent setbacks, including the discontinuation of adezkibart in May 2026.

Why it matters

The success of dazodalibep in Phase 3 represents a potential breakthrough for Sjögren's disease, a condition with significant unmet need and no approved systemic treatments. If approved, it could provide the first disease-modifying therapy for this debilitating autoimmune disorder, improving quality of life for patients who currently rely on anti-inflammatory medications for symptom management. The result also validates the CD40L mechanism of action and may influence the development of other therapies in the autoimmune space. For Amgen, this success is particularly important given recent setbacks in its autoimmune pipeline, including the discontinuation of adezkibart, and could strengthen its position in the market for autoimmune diseases.

What to watch

Amgen plans to present detailed data from the OASIZ 301 study at an upcoming medical conference. The company is also conducting OASIZ 303, a Phase 3 trial for patients with high symptom burden but low systemic disease activity, which is expected to complete in Q4 2026. Additionally, Amgen is running OASIZ 304, an open-label long-term extension study to evaluate the long-term safety and tolerability of dazodalibep in eligible participants from both OASIZ 301 and OASIZ 303. The FDA will likely require two positive Phase 3 readouts before considering approval, so the outcome of OASIZ 303 will be critical for the drug's regulatory path.