** Shares of Larimar Therapeutics LRMR.O fall 31% to $3.50 premarket on safety concerns about its experimental drug, nomlabofusp, after data from a long-term study

** Drug was being tested for Friedreich's ataxia, a rare genetic disorder that causes progressive damage to the nervous system

** Seven participants experienced anaphylaxis within the first 6 weeks of dosing and were withdrawn from the study, co says

** Anaphylaxis is a sudden and severe allergic reaction that can cause breathing problems, swelling and a drop in blood pressure

** "The major downside is that we continue to see anaphylaxis" - Jones Trading analyst Catherine Novack

** As of last close, stock up 31% YTD

(Reporting by Kamal Choudhury in Bengaluru)

((Kamal.Choudhury@thomsonreuters.com;))