** Shares of biotech firm Greenwich LifeSciences GLSI.O rise 6.6% to $29.99 premarket
** Co says its experimental drug GLSI-100 cut the risk of breast cancer coming back in an ongoing late‑stage study
** The annual cancer return rate was under 1% in 250 patients who completed the primary injections, co says
** Adds annual cancer return rate was about 4% a year in a similar group treated with standard drug Kadcyla in an earlier study
** Data tracked over about 1.2 years in the ongoing GLSI-100 study implies an 83% drop in recurrence; most patients had prior Kadcyla - GLSI
** Co adds results are preliminary and will be updated as the study continues
** GLSI rose ~87% in 2025
(Reporting by Sahil Pandey in Bengaluru)
((Sahil.Pandey@thomsonreuters.com))