Dianthus Therapeutics reports 75% CIDP response rate and $1.2bn cash

Dianthus Therapeutics has reported a 75% responder rate in the interim analysis from the first 40 participants completing Part A of its Phase 3 CAPTIVATE trial of claseprubart in chronic inflammatory demyelinating polyneuropathy (CIDP), exceeding the company's prespecified 50% benchmark. The New York and Waltham-based biotech also initiated its Phase 3 EMERGE registrational trial in generalised myasthenia gravis (gMG) in June and disclosed a new internally developed pipeline asset, DNTH312, alongside second-quarter financial results.

Claseprubart is a selective monoclonal antibody targeting the active form of C1s, a component of the classical complement pathway. It is engineered for subcutaneous self-administration at dosing intervals of two or four weeks, properties Dianthus says could differentiate it from intravenous complement inhibitors already on the market. The FDA granted claseprubart Orphan Drug Designation for myasthenia gravis in May 2026.

Pipeline progress across three indications

In CIDP, the company said results were consistent across multiple efficacy measures and that claseprubart was generally well tolerated, with no related serious adverse events, no discontinuations due to safety, and no cases of drug-induced lupus or SLE observed across any programme to date. Full guidance on the timing of Part B top-line data from CAPTIVATE is expected by year-end 2026.

Enrolment in the Phase 2 MoMeNtum trial in multifocal motor neuropathy (MMN) has been completed at 46 patients, exceeding the original target of 36. Top-line results are anticipated in December 2026. The Phase 3 EMERGE trial in gMG, evaluating 300mg dosing at both two-week and four-week intervals, is expected to deliver top-line data in the second half of 2028.

Beyond the claseprubart franchise, Dianthus is advancing DNTH212, a bifunctional fusion protein targeting BDCA2 and BAFF/APRIL to suppress both innate and adaptive immune activity. Healthy volunteer data from an ongoing Phase 1 study in China are anticipated by year-end, with Sjögren's disease, systemic lupus erythematosus, and dermatomyositis named as the first priority indications. The newly disclosed DNTH312 combines claseprubart's aC1s inhibition with TACI-mediated BAFF/APRIL suppression in a single molecule, and is described by the company as first-in-class. It is expected to be Phase 1 ready by the end of 2027.

Financial position and competitive context

Dianthus ended June with approximately $1.2 billion in cash and investments, a position the company says provides runway into 2030. R&D expenditure rose sharply to $48.7 million in Q2 2026, up from $26.3 million in Q2 2025, driven by expanding clinical activity. The net loss for the quarter was $50.2 million, or $0.90 per share. The company's share count has grown materially year-on-year, reaching a weighted average of approximately 56 million, which implies a significant equity raise in the intervening period, though the release did not detail the transaction.

The complement inhibitor space is increasingly competitive. Argenx's efgartigimod and UCB's rozanolixizumab are approved in gMG, while Annexon, Inhibrx, and others are active in adjacent complement programmes. In CIDP specifically, argenx gained approval for efgartigimod alfa and hyaluronidase-qvfc in 2023, making it the benchmark Dianthus will need to demonstrate clinical superiority or meaningful differentiation against. The 75% CAPTIVATE interim response rate, if it holds in Part B and translates into a robust placebo-controlled signal, would represent a competitive data package. Investors will watch the year-end CAPTIVATE Part B timing update closely, as it will shape the approval and commercial timeline.

Chief executive Marino Garcia said the interim CIDP results and the breadth of the pipeline reflect the company's focus on building a "best-in-disease, pipeline-in-a-product" platform in autoimmune disease, though the company has not yet disclosed regulatory conversations on a potential accelerated approval pathway for any of its programmes.