** Shares of drugmaker Rhythm Pharmaceuticals RYTM.O rise 6.3% to $96.03 premarket

** Co said on Thursday the U.S. FDA approved its treatment, Imcivree, as the first therapy for acquired hypothalamic obesity, a rare form of obesity caused by damage to the brain region that regulates hunger and weight

** Co said approval comes after late-stage trial showed patients on Imcivree cut body mass index by about 16% over a year, vs. an increase on those given placebo

** RYTM added therapy was generally well-tolerated and common side effects included skin darkening, nausea, vomiting and headache

** FDA approval allows therapy to be used in adults and children aged four and above

** Imcivree was already approved for certain rare genetic forms of obesity; drug to be available immediately in the U.S. - Co

** Shares of the company down about 16% YTD after nearly doubling in value in 2025

(Reporting by Sahil Pandey in Bengaluru)

((Sahil.Pandey@thomsonreuters.com))