Novartis announced disappointing results from its Phase III GCAptAIN study evaluating Cosentyx (secukinumab) for the treatment of giant cell arteritis (GCA), with the interleukin-17A inhibitor failing to meet its primary endpoint of sustained remission at Week 52 in adults with newly diagnosed or relapsing disease.
The global, multicenter, randomized, double-blind, placebo-controlled study conducted across 27 countries compared Cosentyx in combination with a 26-week steroid taper against placebo plus a 52-week steroid taper. Despite the negative primary outcome, Cosentyx demonstrated numerically favorable results compared to placebo for cumulative steroid dose and steroid-related toxicity, though these secondary endpoints did not reach statistical significance.
Study Design and Results
The GCAptAIN trial (NCT04930094) randomized patients into three treatment arms: Cosentyx 300 mg, Cosentyx 150 mg, or placebo, all administered in combination with a glucocorticoid taper regimen. The primary endpoint assessed whether secukinumab 300 mg subcutaneous injection plus a 26-week glucocorticoid taper was superior to placebo plus a 52-week glucocorticoid taper in achieving sustained remission at Week 52.
Safety in GCA patients was consistent with the known safety profile of Cosentyx, which is supported by robust evidence and 10 years of real-world data across its approved indications. The drug has been used to treat more than 1.8 million patients worldwide since its 2015 launch and is now approved in over 100 countries.
"While the Phase III results of GCAptAIN did not replicate the positive outcomes observed in the Phase II trial, we remain committed to continuing to drive scientific progress and deepening the understanding of immune-mediated diseases," said Shreeram Aradhye, M.D., President, Development and Chief Medical Officer, Novartis.
Clinical Significance of Giant Cell Arteritis
Giant cell arteritis represents the most common form of systemic vasculitis, primarily affecting people over 50 years of age. The condition is considered a medical emergency requiring prompt recognition and treatment due to its potential to cause irreversible vision loss and life-threatening aortic aneurysms. Beyond its physical complications, GCA significantly impairs quality of life, contributing to fatigue, cognitive difficulties, and reduced independence.
Cosentyx's Established Portfolio
Cosentyx is a fully human biologic that directly inhibits interleukin-17A, an important cytokine involved in the inflammation underlying multiple immune-mediated inflammatory diseases. The drug is currently approved for use in adults with psoriatic arthritis, moderate to severe plaque psoriasis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, and hidradenitis suppurativa, as well as in pediatric patients with psoriasis, enthesitis-related arthritis, and juvenile psoriatic arthritis.
In the first quarter of 2025, Cosentyx sales increased 18% to $1.53 billion, driven by recent launches including the hidradenitis suppurativa indication and the intravenous formulation in the United States, along with volume growth in core indications.
Next Steps
Novartis plans to complete a full evaluation of the GCAptAIN data and share the results at a later date. The company continues to focus on addressing areas of unmet medical need in immune-mediated diseases despite this setback in the GCA indication.
