Cyclerion soars on merger deal with Korsana

Shares of biotech firm Cyclerion Therapeutics CYCN.O soar nearly threefold to $4.83 in premarket trading

Co says it will merge with private firm Korsana Biosciences and focus on treatments for Alzheimer's, a neurodegenerative disorder that impacts memory and thinking

Cyclerion shareholders will own about 1.5% of the new company, which will trade as Korsana Biosciences on Nasdaq under "KRSA"

CYFN says combined entity to get $380 mln in private funding led by Fairmount and Venrock, enough to fund operations through 2029

CYFN to build on Korsana's lead experimental drug, KRSA-028, an antibody treatment being developed to treat Alzheimer's by targeting toxic brain proteins

Says early testing among healthy volunteers planned for mid-2027, with initial patient data due later that year

As of last close, stock up ~22% YTD