- In order to increase homogeneity ** In order to accelerate inclusion, patients using combined metformin/SU derivative will be considered. In these patients, a 12 week wash-out period of the SU derivative will be observed, only when combined use has led to a HbA1c <8% at screening. Subsequently, patients will be eligible to enter the study, now using metformin monotherapy, provided that HbA1c still meets inclusion criteria.