Novartis shares tumble after second late-stage drug setback

(Sharecast News) - Shares in Novartis tanked on Tuesday, with the stock on track for its worst daily performance on record, after disappointing results from a clinical trial of its muscle-wasting disease treatment.

The news adds further pressure to the Swiss pharma giant's pipeline following another clinical setback announced the day before.

Novartis said its global Phase III HARBOR study of delpacibart etedesiran, or del-desiran, in patients with myotonic dystrophy type 1 (DM1) did not demonstrate a statistically significant improvement against placebo on its primary endpoint, 'video hand opening time', which is a novel measure of hand myotonia.

However, the company said the drug showed evidence of clinical activity across secondary endpoints and exploratory analyses, while safety findings were generally consistent with previously reported data. Novartis is now evaluating the full dataset and will engage with health authorities to determine the programme's development path.

Chief medical officer Shreeram Aradhye said: "Developing therapies for a complex disease like DM1 remains challenging, and setbacks are part of scientific progress."

Del-desiran was acquired through Novartis's purchase of Avidity Biosciences and is one of three antibody oligonucleotide conjugate therapies added to its neuromuscular pipeline.

Despite the disappointment, the company maintained its guidance for 5% to 6% compound annual sales growth between 2025 and 2030.

By 1217 BST, the stock was down 9.4% at CHF113.70.

The latest news comes a day after Novartis shares fell more than 3% following the failure of its cholesterol drug pelacarsen to reduce the risk of cardiovascular events in a Phase III trial.