The mean ( standard error ) weight change was -0.42 ( 0.2 ) kg with albiglutide , +4.4 ( 0.2 ) kg ( p < 0.001 ) with pioglitazone , and -0.40 ( 0.4 ) kg with placebo and serious adverse events occurred in 6.3 , 9.0 and 6.1 % of participants in the respective groups .