Amgen has reported positive Phase 3 results for dazodalibep, an experimental monoclonal antibody designed to target the CD40 ligand pathway involved in immune-cell signaling and in development for Sjögren's disease, advancing efforts to bring a new treatment option to patients with the condition. The drug joined Amgen's pipeline through its 2023 acquisition of Horizon Therapeutics. In the OASIZ-301 trial, both of the drug's dosing regimens significantly reduced systemic disease activity over 48 weeks, and one regimen also improved patient-reported dryness symptoms. Despite the positive trial data, Amgen (AMGN) shares declined 0.77% to $461.63, a loss of $3.60, after recovering from intraday lows near $459; as with any single session, a daily move can reflect factors beyond one clinical announcement.

Phase 3 Trial Meets Primary Treatment Goals

Amgen announced that its OASIZ-301 trial met its primary endpoint after 48 weeks of treatment. The randomized study evaluated dazodalibep against placebo in patients with moderate to severe Sjögren's disease. Researchers measured systemic disease activity using the European Alliance of Associations for Rheumatology Sjögren's Syndrome Disease Activity Index.

The 1,500 mg regimen lowered disease activity scores by 5.6 points, compared with a 3.8-point reduction for placebo. The 3,000 mg regimen achieved a 5.2-point reduction over the same period. Both regimens produced statistically significant improvements, supporting dazodalibep's potential as a new treatment option for the disease.

Researchers observed treatment benefits as early as Week 4, with improvements continuing through Week 48. Amgen will present detailed findings at the American College of Rheumatology Convergence 2026 meeting, giving clinicians and researchers a fuller view of the data behind the headline results. The results build on the positive preliminary findings the company announced in September.

Improvements in Dryness and Systemic Symptoms

The trial also showed improvements in dryness symptoms among patients receiving 1,500 mg every four weeks. Using two established patient-reported symptom assessments, researchers recorded significant differences between dazodalibep and placebo. Participants receiving the treatment also showed greater improvements in stimulated salivary flow, an objective measure of oral dryness.

Further analyses showed that more treated patients achieved meaningful reductions in systemic disease activity compared with placebo recipients. Both dosing regimens improved overall patient-reported symptom scores throughout the 48-week study, and researchers identified benefits across several disease areas, including glandular, joint, skin, and biological manifestations.

Sjögren's disease is a chronic autoimmune condition that affects moisture-producing glands, such as those that produce saliva and tears, and can also cause fatigue, joint pain, and organ complications. The United States currently has no FDA-approved treatments specifically for the condition, and successful clinical development could therefore offer another treatment approach for patients with persistent symptoms.

Safety Findings as Development Continues

Amgen reported that the most common adverse events involved infections, hypertension, and infusion-related reactions. These events were generally mild to moderate in severity across the treatment groups. Serious adverse events and treatment discontinuations occurred at comparable rates across the three study arms, which included both dazodalibep regimens and placebo.

Researchers found no imbalance in thromboembolic events or opportunistic infections between treatment groups, while malignancy rates remained low and comparable, adding further information to the drug's safety profile. Dazodalibep still requires further clinical development and regulatory review before potential commercial approval, a process in which U.S. regulators would evaluate the complete body of clinical evidence.

The Phase 3 results strengthen Amgen's development program for a disease with limited treatment options. The company plans to advance broader Phase 3 research while evaluating additional clinical outcomes — the concrete steps to watch as dazodalibep works through the further development and regulatory review required before any potential approval. Its latest findings provide evidence supporting continued development of dazodalibep for Sjögren's disease.

Source: Blockonomi