Novartis announced that its investigational agent del-desiran did not meet the primary endpoint in the Phase 3 HARBOR trial for myotonic dystrophy type 1 (DM1). The result was disclosed in a STAT report dated Sept. 8, 2026. DM1 is a rare neuromuscular disorder characterized by progressive muscle stiffness and weakness, and the HARBOR study was designed to test whether del-desiran could improve clinically meaningful measures of muscle relaxation and function.
The STAT article reports the topline outcome that del-desiran failed to outperform placebo on the trial’s primary efficacy measure, signaling a negative pivotal result for Novartis in this indication.
The HARBOR trial’s primary endpoint was improvement versus placebo on video hand opening time (vHOT). vHOT is a functional assessment that measures the time required for a hand to relax after a squeeze, a metric intended to capture the myotonia and impaired hand relaxation that can occur in DM1.
According to the source text, del-desiran did not achieve superiority over placebo on vHOT in the Phase 3 HARBOR study. The publicly available portion of the STAT report does not include detailed numerical results, secondary endpoint outcomes, subgroup analyses, or safety and tolerability data for del-desiran. Those specifics were not reported in the accessible article.
The HARBOR miss came days after another major Novartis trial failed, amplifying scrutiny of the company’s development portfolio. The STAT report links this neuromuscular setback with a prior pivotal failure in a cardiovascular program (a separate investigational therapy) that was reported earlier in the week. The aggregation of two high-profile trial losses in quick succession is portrayed in the article as likely to raise questions about Novartis’ pipeline resilience and its recent acquisition strategy, especially as the company faces a looming patent cliff.
The STAT piece also notes that Novartis did have a positive outcome in the recent past, with a multiple sclerosis drug registering a victory the previous week. The juxtaposition of wins and losses underscores the mixed near-term clinical and commercial newsflow for the company reported by STAT.
STAT reported that Novartis’ stock fell in early trading in Switzerland, declining by as much as 10% following the trial report. The article frames the HARBOR failure and the earlier cardiovascular miss as developments that could increase investor concerns about Novartis’ future revenue and the effectiveness of its business strategy in replenishing revenue as older products approach loss of exclusivity.
Beyond the stock movement cited, the publicly available article does not provide comments from Novartis leadership, details of planned next steps for the del-desiran program, or explicit descriptions of potential regulatory or clinical remedies. Those items were not disclosed in the accessible portion of the STAT report.
The STAT story communicates the key topline facts: the Phase 3 HARBOR trial of del-desiran in DM1 failed to meet its primary endpoint of improved vHOT, this result followed another recent Novartis pivotal trial loss, and the company’s shares reacted negatively in early trading.
The article is a STAT+ exclusive; the remainder of the piece is behind a subscription paywall. As a result, many granular trial elements are not available in the public text. Specifically, the following items were not reported in the accessible portion of the source article:
Where the STAT article indicated additional detail exists, it was accessible only to STAT+ subscribers; the public portion of the report does not provide the full dataset or company responses.
The accessible STAT report was authored by Andrew Joseph, Europe correspondent, and published Sept. 8, 2026. The article links to the separate STAT report on Novartis’ recent cardiovascular trial failure and references the company’s recent clinical win in multiple sclerosis. The source emphasizes that the HARBOR outcome is a pivotal miss and situates it within the broader narrative of Novartis’ pipeline and market pressures.
If you need further information about trial numbers, safety data, or Novartis’ corporate response, those details were not reported in the public text of the STAT article and would require access to the full STAT+ story, company press releases, clinical-trial registries, or regulatory filings for verification.