This study will comprise of 3 study periods : screening (2 weeks), treatment (26 weeks) and for those subjects not entering the extension study a follow-up period (8 weeks). Approximately 300 subjects will be randomized in a 1:1 ratio to either Albiglutide active liquid auto-injector (LAI) plus Placebo lyophilized DCC pen injector (lyophilized DCC PI); or, Albiglutide lyophilized DCC PI plus Placebo LAI.