** Shares of drugmaker BioMarin Pharmaceutical BMRN.O fall 2.3% to $50.65

** Co says its experimental treatment for a rare genetic condition did not meet one of the two main goals in a late-stage study

** BMRN was testing its enzyme replacement therapy called BMN 401 in children aged 1 to 12 years with ENPP1 deficiency, a rare, lifelong genetic condition

** Children with ENPP1 deficiency typically develop a type of rickets which causes weak bones and may cause pain and difficulty with movement

** BRMN says the trial did not show an improvement in a measure of the treatment's impact in children with rickets

** Including session's move, stock down 14.9% YTD