In SURPASS-6, how efficacious and safe was tirzepatide (TZP) based on residual insulin
use at Week 52?
Methods: In the SURPASS-6 trial, TZP was added to basal insulin glargine U100 in participants
with inadequately controlled long-standing type 2 diabetes (T2D). “Insulin regressor”
was defined as basal insulin discontinuation or<10 IU/day, and “insulin non-regressor”
as≥10 IU/day, at 52 weeks. Included only participants receiving TZP at Week 52 (≥75%
compliance) without rescue medication. Efficacy analyses used a mixed model for repeated
measures.
Results: Overall, 145 and 496 TZP-treated participants were included in the insulin regressor
vs. insulin non-regressor groups, respectively. At baseline, mean age was 58.4 vs.
58.2 years, and median basal insulin dose was 40.0 vs. 48.0 IU/day. From baseline
to Week 52 in the insulin regressor and insulin non-regressor groups, respectively,
mean HbA1c of 8.5% and 8.9% was reduced to 5.9% and 6.7%, while weight was substantially
reduced by 16 kg and 8 kg. Clinically significant hypoglycemia was also less frequent
in the insulin regressor group.
Conclusion: In basal insulin–treated T2D, participants who regressed on insulin use also achieved
near-normoglycemia and substantial weight loss.