Introduction: Two phase 3 randomized controlled studies (ADJUNCT ONE (Clinicaltrials.gov: NCT01836523), ADJUNCT TWO (Clinicaltrials.gov: NCT02098395)) evaluated liraglutide (1.8, 1.2 or 0.6 mg) vs placebo in participants with type 1 diabetes (T1D) as an adjunct to insulin therapy. This paper aims to improve our understanding of the potential mechanisms leading to premature discontinuation of this treatment regimen.
Methods: Post hoc comparisons were conducted on baseline characteristics and adverse event (AE) rates of participants completing and not completing the ADJUNCT studies due to AEs/lack of tolerance using summary tables and variance analysis.
Results: Non-completers (liraglutide and placebo combined) had lower baseline body mass index (BMI) (ADJUNCT ONE: 27.8 kg/m2 vs 29.8 kg/m2, P < .0001; ADJUNCT TWO: 26.3 kg/m2 vs 29.2 kg/m2, P < .0001), longer duration of T1D (25.8 years vs 21.0 years, P < .0001; 24.1 years vs 21.0 years, P = .04), lower daily insulin doses by continuous infusion (46.4 U vs 57.3 U, P = .01; 40.9 U vs 57.4 U, P = .12) or multiple injections (58.4 U vs 68.5 U, P = .006; 56.0 U vs 65.8 U, P =.03) and a higher proportion of participants with undetectable C-peptide (91.5% vs 81.3%; 87.0% vs 84.9%) compared to completers. When analyzed by treatment group, only duration of T1D and C-peptide differed between completers and non-completers among liraglutide (and not placebo) participants. The AE rates were higher for non-completers.
Conclusion: Individuals with longer-standing T1D and low levels of C-peptide at baseline were more likely to discontinue adjunctive liraglutide treatment due to AEs/lack of tolerance than individuals with residual insulin production. Lower BMI predicted a greater likelihood of non-completion for the included participants, regardless of treatment. These new findings may be relevant for clinical practice.
Keywords: GLP-1 receptor agonist; adjunctive therapy; baseline data; discontinuation; liraglutide; type 1 diabetes.