Ireland's Prothena drops as Jefferies downgrades to 'hold' after drug fails trial

Shares of therapy developer Prothena Corporation PRTA.O are down nearly 2% at $4.77 in pre-market trading

Jefferies downgrades the stock's rating to "hold" from "buy"; slashes PT to $6 from $32, a 8.8% discount to the last close

PRTA becomes stock with lowest PT, per Jefferies, on Wall Street

We see uncertainty around the pipeline given the failure of the AL amyloidosis (a disease where abnormal proteins damage organs) drug - brokerage

Adds it finds "risk" in the co's Alzheimer's drug PRX012 phase 1 trial data

Co says phase 3 clinical trial of Birtamimab in patients with AL amyloidosis did not meet primary endpoint

Avg rating of 10 analysts is "buy"; median PT $29.5— data compiled by LSEG

PRTA falls ~52.49% YTD, up to last close