Novartis announced that its blockbuster drug Cosentyx failed to outperform placebo in a Phase 3 study targeting giant cell arteritis, an autoimmune blood vessel disorder. The antibody therapy was being evaluated as a treatment alternative to established Roche and AbbVie drugs approved for this rare condition. The setback delays potential label expansion efforts and underscores challenges in addressing vascular autoimmune diseases despite Cosentyx's success in other indications.