Tirzepatide shows clinical and cost-effectiveness for Type 2 Diabetes in Canada via transportability analysis

Type 2 Diabetes (T2D) is a chronic metabolic disease requiring effective and cost-efficient treatments. While new therapies like tirzepatide show promise in global trials, their real-world applicability and economic value can vary by region due to differences in patient populations and healthcare systems. Local decision-makers need evidence tailored to their specific context. This study addresses this gap by using transportability analysis to estimate tirzepatide's clinical and cost-effectiveness for the Canadian population.

Researchers applied Bayesian transportability analysis to patient-level data from the SURPASS-3 trial and the Canadian Community Health Survey. Survey data were harmonized to match trial eligibility. Adjustments were made for baseline bodyweight, sex, age, and race to estimate comparative effectiveness of tirzepatide versus insulin degludec for weight loss. Subgroup analyses assessed effectiveness by region, age, and sex. A decision tree model and Bayesian approach estimated short-term cost-effectiveness from a Canadian payer perspective, comparing incremental cost-effectiveness ratios (ICERs) from original and transported effects.

Both trial and transported effects confirmed tirzepatide's clinical benefit for weight loss, observed across all Canadian provinces/territories and age/sex categories. The trial effects, reflecting efficacy, were consistently larger than the transported effects, indicating a difference between controlled trial outcomes and real-world population estimates. Although incremental costs were similar, the reduced incremental benefits estimated with the transported effects resulted in a higher ICER.

The incremental cost-effectiveness ratio (ICER) for tirzepatide compared to insulin degludec was $599.40 under the transported scenario, slightly higher than the $577.40 from the original trial scenario.