Novartis Myotonic Dystrophy Drug Fails to Meet Primary Goal in Late-Stage Trial

Novartis announced Tuesday that its experimental drug for myotonic dystrophy type 1 (DM1) failed to meet the primary endpoint in a late-stage clinical trial. The outcome represents a significant setback in the search for a treatment for the progressive neuromuscular disease, which currently has no approved therapies.

Trial Results

The drug, delpacibart etedesiran (del-desiran), was evaluated in the global Phase III HARBOR study, which included approximately 150 participants. The trial's primary endpoint was the measurement of hand muscle stiffness, assessed by video hand opening time.

According to Novartis, del-desiran did not demonstrate a statistically significant improvement compared to a placebo over the 54-week study. The Swiss drugmaker noted that while the main goal was missed, the study did show evidence of clinical activity in other measures. The company stated that safety findings were generally consistent with previous data.

Next Steps and Context

Novartis plans to evaluate the full dataset and consult with health authorities to determine the future development path for the drug. "Developing therapies for a complex disease like DM1 remains challenging, and setbacks are part of scientific progress," said Shreeram Aradhye, Novartis’s President of Development and Chief Medical Officer.

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DM1 is a serious genetic disorder, and del-desiran, an antibody oligonucleotide conjugate, had received multiple special designations from regulators, including Orphan Drug and Breakthrough Therapy status from the U.S. Food and Drug Administration, highlighting the high unmet need for a viable treatment.

Financial Outlook Maintained

Despite the trial failure, Novartis reaffirmed its financial guidance. The company said it maintains its five-year sales compound annual growth rate (CAGR) forecast of 5% to 6% for the period of 2025 to 2030.

Del-desiran is one of three antibody oligonucleotide conjugate therapies Novartis acquired through its deal with Avidity Biosciences. The company noted that the other two drugs in this class, targeting Duchenne muscular dystrophy and facioscapulohumeral muscular dystrophy, continue to advance in development.