Novartis AG reported a setback in its Phase III clinical development program after the Harbor trial for del-desiran missed its primary endpoint in patients with myotonic dystrophy type 1.
Del-desiran, an RNA-targeted therapeutic candidate, was advanced as part of Novartis' broader strategy following its $12 billion acquisition of Avidity Biosciences. The failed trial marks a significant disappointment for the Swiss pharmaceutical giant, which had positioned the asset as a centerpiece of its pipeline expansion through the deal.
The miss raises questions about the return on investment from one of the sector's largest acquisitions in recent years. Novartis, a heavy-weight component of the Swiss Market Index (SMI), now faces uncertainty over whether the Avidity buyout will deliver the expected clinical and commercial returns.
Myotonic dystrophy type 1 is a rare, progressive genetic disorder affecting multiple body systems. Developing treatments for such conditions typically involves substantial R&D outlays and long development timelines, making late-stage failures particularly costly.
Novartis has not yet provided updated guidance or a timeline for potential alternative development strategies for del-desiran beyond the Harbor trial results.
