** Shares of drug developer Nektar Therapeutics NKTR.O fall 6.8% to $50 premarket

** Co says its experimental drug for alopecia areata, rezpegaldesleukin, narrowly missed the main goal of achieving statistically significant reduction in severity in a mid-stage study

** Says both treatment arms met statistical significance on the main goal when excluding four patients with major study eligibility violations

** Alopecia areata is an autoimmune condition where the body's immune system attacks hair follicles, causing patchy hair loss on the scalp

** Co plans to move into late-stage development for the drug in 2026

** As of last close, stock has more than tripled YTD

(Reporting by Christy Santhosh and Kamal Choudhury)

((Christy.Santhosh@thomsonreuters.com))