Novartis Drug Fails Its Main Test in a Muscle Disease With No Approved Treatment

Novartis reported on Sept. 8 that its Phase III HARBOR trial of del-desiran missed its main goal. The drug did not produce a statistically significant improvement over placebo on video hand-opening time, a timed measure of how fast a patient can open a clenched hand, in people with myotonic dystrophy type 1, or DM1.

DM1 has no approved treatment. The release describes it as a progressive disease caused by a repeated stretch of DNA in a single gene. Patients can experience muscle weakness, impaired hand function and myotonia, a difficulty relaxing a muscle after gripping. Del-desiran was designed to target that underlying cause.

HARBOR was a global study that enrolled about 150 people and ran for 54 weeks, with participants randomly assigned to receive del-desiran or placebo, according to the company's release. Secondary measures included grip strength, muscle testing, a daily-activities score and a timed walk/run test.

Novartis said it saw evidence of clinical activity in secondary measures and exploratory analyses, and that safety findings were generally consistent with previously reported data. Those are the company's own readings of data it has not published.

"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. The company said it will evaluate the full HARBOR dataset and engage with health authorities to determine a development path for del-desiran.

Del-desiran came to Novartis through its acquisition of Avidity Biosciences, along with two other drug candidates of the same type. The release says the U.S. Food and Drug Administration has granted priority review to one of them, delpacibart zotadirsen, in a form of Duchenne muscular dystrophy.