0001755237 2026-09-08 2026-09-08 0001755237 dei:FormerAddressMember 2026-09-08 2026-09-08 NASDAQ false --12-31 0001755237 8-K 2026-09-08 Korsana Biosciences, Inc. MA 001-38787 83-1895370 203 Crescent Street Bldgs. #3/3A/4 Suite 503 Waltham MA 02453 781 516-2325 Cyclerion Therapeutics, Inc. 245 First Street 18th Floor Cambridge MA 02142 false false false false Common Stock, no par value per share KRSA false