Novartis' del-desiran misses primary goal in late-stage myotonic dystrophy trial

Novartis announced that its experimental RNA drug del-desiran did not achieve the primary endpoint in a late-stage study of myotonic dystrophy type 1, a rare muscle‑weakening disease.

The trial measured patients' ability to relax hand muscles, and the drug performed no better than placebo on this key test, although researchers noted some activity on secondary measures.

Myotonic dystrophy type 1 is caused by genetic mutations that lead to toxic RNA buildup, disrupting proteins needed for muscle relaxation and affecting multiple organs.

Analysts said the setback could raise questions about the $12 billion acquisition that brought the drug into Novartis' pipeline and the company's broader dealmaking strategy.