Dianthus Therapeutics (DNTH) Soars 20% Intraday, 34.92% in 5 Days on Positive Trial Results and Capital Raise

Dianthus Therapeutics (DNTH) surged 20% in intraday trading on September 8, 2025, reaching its highest level since September 2025, with an intraday gain of 23.77%. The stock has now risen 34.92% over five consecutive days, driven by positive developments in its pipeline and capital-raising initiatives.

The recent momentum stems from strong Phase 2 trial results for claseprubart (DNTH103), Dianthus’ lead candidate for generalized myasthenia gravis (gMG). The trial demonstrated rapid and sustained improvements in key endpoints, including MG-ADL and QMG scores, with both 300mg and 600mg subcutaneous doses showing efficacy as early as Week 1. Notably, the 300mg dose matched the 600mg dose in multiple metrics while avoiding significant autoimmune risks, positioning the drug as a potential best-in-class therapy with a favorable safety profile.

Claseprubart’s subcutaneous autoinjector design, administered every two weeks, offers a convenient alternative to existing therapies like AstraZeneca’s Ultomiris and Argenx’s Vyvgart. Analysts highlighted its potential to disrupt the gMG market, particularly due to its rapid onset of action and lack of regulatory hurdles such as a “Boxed Warning” for meningococcal infections. The absence of serious adverse events in the trial further strengthens its competitive edge.

Meanwhile, Dianthus raised $150 million through a public offering, with an additional $22.5 million in underwriting options, to fund clinical development and operational needs. While the capital infusion supports its expansion, concerns about equity dilution may temper long-term enthusiasm. The company is also advancing claseprubart into Phase 3 trials for gMG and plans to expand its pipeline into conditions like CIDP and MMN, with data expected in late 2026.

Challenges remain, however. The development of anti-nuclear antibodies (ANAs) in 6% of the 300mg group and 36% of the 600mg group raises safety concerns, prompting Dianthus to prioritize the lower dose for Phase 3. Competitors such as Sanofi’s riliprubart and entrenched therapies like Vyvgart could also pose barriers to adoption. Analysts caution that claseprubart’s success will depend on its ability to demonstrate cost-effectiveness and secure regulatory approval, with Phase 3 trial initiation in 2026 a critical next step.