X0609 4 2026-09-09 0001755237 Korsana Biosciences, Inc. KRSA 0002126413 Pernice Michelle Patricia false C/O KORSANA BIOSCIENCES, INC. 203 CRESCENT STREET, SUITE 503 WALTHAM MA 02453 true false false false false Stock Option (Right to Buy) 26.20 2026-09-09 4 A false 48445 0 A 2036-09-09 Common Stock 48445 48445 D This option represents the right to purchase 48,445 shares of the Issuer's common stock and will vest in equal monthly installments through September 9, 2029, subject to the Reporting Person's continued service to the Issuer on each such vesting date. /s/ Mark Vignola, as attorney-in-fact for Michelle Pernice 2026-09-10