Amgen's Sjögren's drug succeeds in first Phase 3 trial

Amgen's stock rose up to 5% on Tuesday after the company announced its drug candidate dazodalibep succeeded in the first of two Phase 3 trials for Sjögren's syndrome. The treatment achieved a statistically significant and clinically meaningful improvement on a key measure of disease activity after 48 weeks.

According to Amgen's statement, positive effects were observed as early as four weeks after treatment began and persisted through the evaluation period. The company said side effects were generally mild to moderate, with infrequent and balanced study discontinuations across treatment groups.

Safety Profile and Mechanism

Investigators reported no imbalance in the rate of blood clots or opportunistic infections in the Phase 3 study. These were potential concerns for drugs with dazodalibep's mechanism of action. The drug works by blocking the CD40-CD40L pathway, a key communication channel between immune cells. This is meant to blunt the hyperactive immune response and formation of tissue-damaging autoantibodies seen in Sjögren's.

Sjögren's syndrome is an autoimmune disorder where the immune system attacks moisture-producing glands, leading to chronic dry eyes and mouth, pain, and inflammation. Patients have a higher risk of lymphoma. There are currently no approved treatments that can alter the course of the disease.

Drug's Development History

The drug has a complex corporate history. Dazodalibep was originally discovered by AstraZeneca. It was later spun into a startup called Viela Bio, which Horizon Therapeutics acquired in 2021. Amgen then bought Horizon two years later, inheriting dazodalibep along with other prospects.

Earlier promise was shown in a Phase 2 trial, where participants experienced a reduction in symptoms and disease activity. Ghaith Noaiseh, the study's lead investigator and an immunology professor at the University of Kansas Medical Center, said in Amgen's statement that the new results provide further support for dazodalibep as an emerging treatment.

Competitive Landscape and Next Steps

Detailed findings from the trial have not been released and will be disclosed at a future medical meeting. This makes it unclear how Amgen's drug compares to other emerging competitors. The competitive field includes other late-stage candidates.

Analyst David Risinger of Leerink Partners wrote that the specifics Amgen presents will help inform positioning against Novartis's ianalumab. He added that his team and other analysts have very low expectations for the Bristol Myers study testing Sotyktu, a marketed psoriasis drug, in Sjögren's.

In a separate note, William Blair analyst Matt Phipps wrote he was encouraged by the announcement, as his team had viewed the dazodalibep program as relatively high risk. He cautioned that Amgen's two Phase 3 trials involve distinct patient populations. The company will need victories in both studies to win regulatory approval. The second trial, focusing on patients with a high symptom burden, is expected to produce data in the fourth quarter of this year.