Amgen's Sjögren's Candidate Hits Its Phase 3 Endpoint

OASIZ 301 Meets Primary Endpoint

In a release dated September 22, 2026, Amgen said its Phase 3 OASIZ 301 study of dazodalibep in adults with moderate-to-severe systemic Sjögren's disease met its primary endpoint at Week 48. The company said the improvement in systemic disease activity was statistically significant and clinically meaningful, with improvements observed as early as Week 4 and sustained through Week 48.

Amgen announced positive topline results from the phase 3 OASIZ 301 trial, meeting its primary endpoint with statistically significant and clinically meaningful improvement at week 48, as measured by the EULAR Sjögren Syndrome Disease Activity Index (ESSDAI).

What Dazodalibep Is

Dazodalibep is a CD40 ligand antagonist, and Amgen says a second Phase 3 trial is expected to read out in the fourth quarter. Amgen's experimental drug dazodalibep met the primary endpoint in a Phase 3 trial for moderate-to-severe systemic Sjögren's disease, showing statistically significant and clinically meaningful improvement after 48 weeks.

The drug is a fusion protein targeting CD40L on T cells, blocking CD40-CD40L co-stimulation that drives B cell hyperactivity, autoantibody production and glandular inflammation central to Sjögren's.

The Clinical Result in Detail

Amgen said its Phase 3 OASIZ 301 study in adults with Sjögren's disease and moderate-to-severe systemic disease activity met its primary endpoint. The company reported statistically significant and clinically meaningful improvement at Week 48, measured by the EULAR Sjögren's Syndrome Disease Activity Index, with improvements observed as early as Week 4 and sustained through Week 48.

Reports noted a 6.3-point ESSDAI reduction versus placebo, exceeding the minimal clinically important difference of 3 points. The trial is one of few Phase 3 successes in systemic Sjögren's, a disease where hydroxychloroquine, rituximab and many candidates have failed.

Market Reaction and Pipeline Context

Amgen shares rose as much as 4% in morning trading after the results, highlighting the market's focus on the company's pipeline as an important source of future growth. Amgen stock after-hours was reported at EUR 369.03 versus prior close EUR 354.53, and Amgen stock gains 1.59 percent on announcement day.

And Amgen's dazodalibep has hit its Phase 3 primary endpoint in Sjögren disease in the BioPharm Brief, with MariTide still the larger growth opportunity, but with more company now from other pipeline products.

What Sjögren's Syndrome Is and Why It Matters

Sjögren's syndrome is an autoimmune disease causing dry eyes, dry mouth, fatigue and systemic organ involvement including joints, lungs and nerves. No systemic therapy is approved; treatment is symptomatic. Prevalence is ∼0.5% with strong female predominance, making even modest disease activity improvements clinically valuable.

Second Phase 3 Readout Coming

A second Phase 3 study is expected to report results in the fourth quarter of 2026, while full data from the first study will be presented at a medical meeting. That second trial, OASIZ 302, tests dazodalibep in patients with more symptomatic burden including dryness and fatigue measured by ESSPRI.

Amgen acquired dazodalibep via Horizon Therapeutics, which had advanced it for Sjögren's. Success would give Amgen a first-in-class CD40L antagonist in rheumatology and diversify beyond Repatha, Evenity and oncology.

Implications for Patients and Next Steps

If approved, dazodalibep would be the first targeted biologic for systemic Sjögren's, offering disease modification rather than artificial tears and saliva. The 48-week benefit sustained from Week 4 suggests rapid onset and durability, important for a chronic disease where patients cycle through ineffective therapies.

Regulatory filings are expected in 2027 pending second Phase 3 data, with potential for breakthrough designation given unmet need.

Working Source Links:

Amgen's Dazodalibep Meets Primary Endpoint in Phase 3 Sjögren's Trial - https://www.biopharminternational.com/view/amgen-dazodalibep-primary-endpoint-phase-3-sjogrens-trial

The BioPharm Brief: Earlier Treatment, New Testing, and Sjögren's Data - Amgen's dazodalibep has hit Phase 3 primary endpoint - https://www.biopharminternational.com/view/the-biopharm-brief-earlier-treatment-new-testing-and-sj-gren-s-data

Amgen stock after-hours: EUR 369.03 - OASIZ 301 met primary endpoint - https://www.ad-hoc-news.de/boerse/nachboerse/amgen-stock-after-hours-eur-369-03-prior-close-eur-354-53/70258891

Amgen's Sjögren's Drug Candidate Clears Phase 3: What Does It Mean for AMGN Stock - https://skn-finance.com/skn-amgens-sjogrens-drug-candidate-clears-phase-3-what-does-it-mean-for-amgn-stock/

Sjogren's Syndrome Clinical Trial Pipeline: Emerging Therapies - DelveInsight - https://www.abnewswire.com/pressreleases/sjogrens-syndrome-clinical-trial-pipeline-emerging-therapies-and-key-developments-shaping-the-treatment-landscape-delveinsight_840336.html