Novartis' Del-desiran Fails Late-Stage DM1 Study, Shares Fall

Novartis AG NVS announced that the late-stage HARBOR study evaluating del-desiran in people living with myotonic dystrophy type 1 (DM1) failed to meet the primary endpoint.

Del-desiran is an investigational antibody oligonucleotide conjugate (AOC) designed to target the underlying cause of DM1.

The global phase III randomized, double-blind, placebo-controlled study, HARMONY, is evaluating the efficacy and safety of del-desiran over 54 weeks in approximately 150 people living with DM1.

The stock plunged on the news. 

This is the second pipeline setback for NVS in the last five days.  Last week, NVS announced that the late-stage study on investigational candidate pelacarsen, failed.

More on NVS’ Del-desiran Study

Results showed that del-desiran failed to demonstrate a statistically significant improvement over placebo on the primary endpoint of video hand opening time (vHOT), a novel measure of hand myotonia.

However, the study showed evidence of clinical activity across certain secondary endpoints and exploratory analyses. Safety findings from the HARBOR study were generally consistent with previously reported data.

Novartis is conducting a comprehensive evaluation of the full HARBOR dataset and plans to engage with health authorities to determine the most appropriate development path for del-desiran.

The candidate is one of three AOC therapies added to Novartis’ neuromuscular pipeline through its acquisition of Avidity Biosciences.

NVS is also advancing delpacibart zotadirsen (del-zota) for patients with Duchenne muscular dystrophy who have mutations amenable to exon 44 skipping (DMD44). Novartis has filed del-zota for accelerated approval, and the FDA has granted the application Priority Review designation.

Meanwhile, Novartis plans to meet with the FDA to discuss the next steps for delpacibart braxlosiran (del-brax), which is being evaluated in facioscapulohumeral muscular dystrophy, following positive phase I/II biomarker data.

Recent Updates From NVS

Novartis had secured global rights from Ionis Pharmaceuticals IONS to develop, manufacture and commercialize pelacarsen under a licensing and collaboration agreement.

Ionis Pharmaceuticals discovered pelacarsen and led its early development. In February 2019, Novartis exercised its option to license the rights to develop and commercialize pelacarsen as a targeted cardiovascular therapy.

HORIZON did not meet the primary endpoint of reducing the risk of cardiovascular events, a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke and urgent coronary revascularization requiring hospitalization, compared with placebo.

Nonetheless, lower lipoprotein (a), Lp(a), levels were achieved with pelacarsen in this study population, which was receiving guideline-directed treatments, including lipid lowering and antihypertensive therapies.

The failure of this late-stage study is a setback for NVS as it is looking to develop new drugs in the wake of generic competition for some of its blockbuster drugs.

Shares of IONS also declined on the failure news.

Year to date, Novartis shares have lost 0.1% against the industry’s growth of 10.7%.

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2026 marks the largest patent cliff in the company's history.  NVS is currently looking to strengthen its portfolio as generic competition for blockbuster cardiovascular drug Entresto is adversely impacting sales.  Oncology drug Promacta is also facing generic competition.

While strong demand for key growth brands, including Kisqali, Kesimpta, Scemblix, Pluvicto and Leqvio, is boosting the top line, NVS’ pipeline needs to deliver.

The back-to-back setbacks have dampened investor sentiment.

Last week, NVS announced positive top-line results from the late-stage REMODEL-1/-2 studies on remibrutinib in relapsing multiple sclerosis.

Remibrutinib is a highly selective oral Bruton’s tyrosine kinase (BTK) inhibitor that blocks the BTK pathway, reducing the activation of B cells and innate immune cells to modulate immune regulatory networks and associated neuroinflammation.
The studies met their primary endpoint, significantly reducing annualized relapse rate compared with Aubagio in the targeted patient population.

Remibrutinib 25 mg is already approved as Rhapsido by the FDA in September 2025 and the EMA in April 2026 for the treatment of adults with CSU.

NVS’ Zacks Rank & Stocks to Consider

Novartis currently carries a Zacks Rank #3 (Hold). A couple of better-ranked stocks in the drug/biotech sector are Repligen RGEN and Anika Therapeutics ANIK, both sporting a Zacks Rank #1 (Strong Buy) at present. You can see the complete list of today’s Zacks #1 Rank stocks here.

Over the past 60 days, estimates for Repligen’s 2026 earnings per share (EPS) have risen from $1.99 to $2.06, while those for 2027 EPS have increased from $2.57 to $2.61 during the same period. RGEN’s shares have gained 1.9% year to date.

Repligen’s earnings beat estimates in each of the trailing four quarters, with the average surprise being 16.80%.

Over the past 30 days, estimates for Anika Therapeutics’ 2026 EPS have risen from 53 cents to $1.05, while those for 2027 EPS have increased from 74 cents to 95 cents over the same period. ANIK’s shares have surged 117.3% year to date.

 

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