Patterns and trends of utilization of incretin-based medicines between 2008 and 2014 in three Italian geographic areas

Background:The incretin-based medicines GLP1 analogues (GLP1a) and dipeptidyl peptidase-4 inhibitors (DPP4i)are hypoglycaemic agents licensed for the treatment of type 2 diabetes mellitus (T2DM). Although these drugspossess comparable efficacy and low risk of hypoglycaemia, differences in terms of route of administration(subcutaneous versus oral), effect on body weight and gastrointestinal tolerabily can impact their actual use inclinical practice. This study aimed to describe the real-world utilization of incretin-based medicines in the Italianclinical practice.Methods:A multi-database, population-based, descriptive, cohort study was performed using administrative datacollected between 2008 and 2014 from three Italian geographic areas. Subjects aged≥18 were selected. New userswere defined as those with≥1 dispensing of GLP1a or DPP4i during the year of interest and none in the past.Trends of cumulative annual incidence of use in the general adult population were observed. New users of GLP1aor DPP4i were respectively described in terms of demographic characteristics and use of antidiabetic drugs during1 year before and after the first incretin dispensing.Results:The overall study population included 4,943,952 subjects. A total of 7357 new users of GLP1a and 41,907 ofDPP4i were identified during the study period. Incidence of use increased between 2008 (0.2‰for both GLP1a andDPP4i) and 2011 (GLP1a = 0.6‰; DPP4i = 2.5‰) and slightly decreased thereafter. In 2014, 61% of new GLP1a usersreceived once-daily liraglutide while 52% of new DPP4i users received metformin/DPP4i in fixed-dose. The percentageof new DPP4i users older than 65 years of age increased from 30.9 to 62.6% during the study period. Around 12% ofnew users had not received any antidiabetic before starting an incretin.Conclusions:During the study period, DPP4i rapidly became the most prescribed incretin-based medicine, particularlyamong older new user. The choice of the specific incretin-based medicine at first prescription appeared to be directedtowards those with higher convenience of use (e.g. oral DPP4i rather than subcutaneous GLP1a, once-daily liraglutiderather than twice-daily exenatide). The non-negligibile use of incretin-based medicines as first-line pharmacotherapy forT2DM warrants further effectiveness and safety evaluations to better define their place in therapy.