After 24 weeks , the adjusted mean change ( AM ) in HbA1c was -0.7 % ( -8 mmol/mol ; baseline 8.6 % , 70mmol/mol ) in the vildagliptin group and -0.2 % ( -2 mmol/mol ; baseline 8.7 % , 72mmol/mol ) in the placebo group , with a treatment difference of -0.5 % ( -5 mmol/mol ; P < 0.001 ) .