Novartis Drug Fails Key Trial, Shares Sink

Novartis announced Tuesday that its experimental drug deldesiran has failed a pivotal late-stage clinical trial, marking the second significant setback for the Swiss pharmaceutical company's pipeline in less than a week. The drug was being evaluated for the treatment of myotonic dystrophy type 1 (DM1), a rare genetic disorder that causes progressive muscle stiffness and weakness. The Phase III HARBOR study did not meet its primary endpoint, which measured the improvement in a patient's ability to relax their hand muscles, a key indicator of hand myotonia. Deldesiran was acquired by Novartis as part of a substantial $12 billion buyout of Avidity Biosciences late last year. The acquisition was intended to bolster Novartis's pipeline with Avidity's RNA-targeting technology, designed to silence disease-causing genes within muscle cells. However, the failure of deldesiran, which aims to destroy faulty genetic instructions, has raised questions about the underlying technology and Novartis's broader acquisition strategy. Analysts noted that the company had other therapeutic approaches available for DM1 at the time of the Avidity deal.