** Shares of drug developer Korro Bio KRRO.O plunge 76.1% to $7.62 in extended trading

** KRRO says its experimental drug KRRO-110 for a rare lung and liver disease produced a key protein in patients but failed to reach expected levels

** The drug was being tested in Alpha-1 Antitrypsin Deficiency, a rare inherited disorder that can cause severe lung and liver disease

** Co also pauses its licensing deal with Novo Nordisk NOVOb.CO for 12 months, effective November 11

** Co says the collaboration may yield no benefits, prompting Korro Bio to wind down its related R&D activities immediately

** KRRO says Novo Nordisk will reimburse Korro for certain wind-down costs; additionally, Korro announced a 34% workforce reduction

** KRRO stock down 17.5% YTD

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com))