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Getting the latest healthcare news for you
A late-stage trial flop for Novartis' del-desiran has rattled the entire myotonic dystrophy type 1 (DM1) drug development space. Shares of Dyne Therapeutics, Sarepta, and PepGen all tumbled after the drug failed to beat placebo on a key muscle-function measure. With no approved treatments for DM1 and a history of program abandonments, investors are now questioning whether the whole therapeutic approach is viable.
A $12 billion bet just came up short — and it's dragging the whole field down with it.
Novartis' del-desiran, acquired through its $12 billion purchase of Avidity, failed to show a statistically significant improvement over placebo in a late-stage trial for myotonic dystrophy type 1 (DM1) — a rare genetic disorder causing progressive muscle weakness and myotonia. The Swiss pharma giant hasn't released full numerical data yet, saying it's evaluating results and will consult health authorities on next steps.
The fallout was swift. Dyne Therapeutics, Sarepta, and PepGen all saw their stocks sink, with Dyne hit hardest given that its own DM1 candidate, DYNE-101, uses the same primary endpoint — video hand opening time — as the failed Novartis trial. Analysts are now questioning whether the issue lies with the endpoint itself or with the underlying biological mechanism.
By the Numbers:
Why it matters: DM1 remains one of the most treatment-resistant rare diseases, with no approved therapies and a trail of abandoned programs. This setback raises serious questions about whether current trial designs and biological targets are the right approach — and puts pressure on remaining players like Dyne to prove their programs can succeed where Novartis could not.
