The development of extended-action insulin analogues was motivated by the unfavorable pharmacokinetic (PK) profile of the conventional long-acting insulin formulations, generally associated with marked inter and intra patient variability and site-and dose-dependent effect variation. The new ultra-long insulin analogue degludec (IDeg) has the same amino acid sequence as human insulin except for the removal of threonine in the position 30 of the B chain (Des-B30, "De") and the attachment, via a glutamic acid linker ("glu"), of a 16-carbon fatty diacid (hexadecanoic diacid, "dec") to lysine in the position 29 of the B chain. These modifications allow that, after changing from the pharmaceutical formulation to the subcutaneous environment, IDeg precipitates in the subcutaneous tissue, forming a depot that undergoes a highly predictable gradual dissociation. Thus, once-daily dosing of IDeg results in a low peak: trough ratio, with consequent low intra-individual variability and plasmatic concentrations less critically dependent upon the time of injections. The clinical development program of IDeg (BEGIN) was comprised of 9 therapeutic confirmatory trials of longer duration (26-52 weeks) and showed that the efficacy of IDeg is comparable to insulin glargine in type 1 (T1D) and type 2 (T2D) diabetes patients across different age, body mass index and ethnic groups. This new ultra-long insulin analogue presents as advantages flexibility in dose timing and lower risk of hypoglycemia.7 Novo Nordisk Inc.