Improved HbA1c and body weight in GADA-positive individuals treated with tirzepatide: A post hoc analysis of SURPASS.

Context: People with clinically diagnosed type 2 diabetes (T2D) but positive anti-glutamic acid decarboxylase autoantibodies (GADA), referred to here as latent autoimmune diabetes in adults (LADA), may experience more rapid glycemic deterioration than those with T2D and may benefit from effective diabetes treatment with additional metabolic benefits.

Objective: Assess glycated hemoglobin (HbA1c) and body weight (BW) changes associated with tirzepatide in GADA-positive versus GADA-negative participants with clinical T2D diagnosis.

Design: Post hoc analyses based on pooled data from SURPASS 2-5, using mixed-model repeated measures from the efficacy analysis set, adjusting for study and baseline covariates including age, sex, baseline values, body mass index (BMI), and GADA status.

Setting: N/A.

Patients: N = 3791.

Intervention: Tirzepatide (5, 10, 15 mg).

Main Outcome Measure(s): Change from baseline in HbA1c at Weeks 40 (SURPASS-2, -3, -5) and 42 (SURPASS-4)by GADA status.

Results: In participants with confirmed GADA status, 3671 (96.8%) were GADA-negative and 120 (3.2%) were GADA-positive (76 [63.3%] with low and 44 [36.7%] with high GADA levels). Baseline characteristics were similar between groups, except for slightly lower BMI in GADA-positive versus GADA-negative participants (mean [SD] BMI 32.2 [6.1] versus 33.6 [6.3] kg/m2). At Week 40/42, both groups achieved robust reductions in HbA1c (-2.11% versus -2.32%) and BW (9.2 kg versus -9.6 kg) (p < 0.001, both groups). HbA1c reductions were greater in GADA-negative participants (estimated difference [95% CI]: 0.21% [0.03, 0.39]; p = 0.024) and BW reductions did not differ between groups (0.38 kg [-0.99, 1.75]; p = 0.588).

Conclusions: In this post hoc analysis, tirzepatide was associated with substantial reductions in HbA1c and BW irrespective of GADA status in adults diagnosed with T2D, suggesting that tirzepatide may improve glycemic control in individuals with LADA.