Mirum rises on FDA nod for rare bone disorder drug 

** Shares of drugmaker Mirum Pharmaceuticals MIRM.O rise 2.8% to $92.25 premarket

** The US FDA late on Friday approved MIRM's drug Atebrioz to treat a rare bone disorder known as fibrodysplasia ossificans progressiva (FOP)

** The approval is based off a 63-patient study, in which Atebrioz significantly cut new bone formation compared to placebo at week 24

** FOP causes muscles, tendons and ligaments to gradually transform into bone, restricting movement and leading to severe disability

** MIRM expects to launch the drug in October

** Mirum had licensed the drug from Incyte INCY.O earlier this year for $16 million upfront, along with potential milestone payments and sales royalties

** As of last close, MIRM stock was up 13.56% YTD