X0609 4 2026-09-01 0001690585 Dianthus Therapeutics, Inc. /DE/ DNTH 0001992260 Randhawa Simrat false C/O DIANTHUS THERAPEUTICS, INC. 7 TIMES SQUARE, 43RD FLOOR NEW YORK NY 10036 false true false false EVP, Head of R&D true Common Stock 2026-09-01 4 M false 7500 17.88 A 11500 D Common Stock 2026-09-01 4 M false 6249 21.77 A 17749 D Common Stock 2026-09-01 4 M false 9375 22.07 A 27124 D Common Stock 2026-09-01 4 S false 2600 105.19 D 24524 D Common Stock 2026-09-01 4 S false 7215 106.25 D 17309 D Common Stock 2026-09-01 4 S false 13309 106.74 D 4000 D Stock Option (Right to Buy) 17.88 2026-09-01 4 M false 7500 0 D 2034-01-23 Common Stock 7500 56776 D Stock Option (Right to Buy) 21.77 2026-09-01 4 M false 6249 0 D 2034-05-22 Common Stock 6249 41676 D Stock Option (Right to Buy) 22.07 2026-09-01 4 M false 9375 0 D 2035-02-03 Common Stock 9375 87500 D This transaction was executed pursuant to a Rule 10b5-1 trading plan adopted on August 14, 2025. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $104.50 to $105.46, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $105.53 to $106.52, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $106.53 to $107.31, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range. The shares of common stock underlying this stock option award vest in equal monthly installments over the four years after January 1, 2024, subject to the Reporting Person's continued service to the Issuer on each such vesting date. The shares of common stock underlying this stock option award vest in equal monthly installments over the four years after May 1, 2024, subject to the Reporting Person's continued service to the Issuer on each such vesting date. The shares of common stock underlying this stock option award vest in equal monthly installments over the four years after January 1, 2025, subject to the Reporting Person's continued service to the Issuer on each such vesting date. /s/ Adam Veness, as attorney-in-fact for Simrat Randhawa 2026-09-03