Cost Effectiveness of Tremelimumab Plus Durvalumab for Unresectable Hepatocellular Carcinoma in the USA.

Background: Treating unresectable hepatocellular carcinoma (uHCC) is challenging. Clinical trials have shown that Single Tremelimumab Regular Interval Durvalumab (STRIDE) offers clinical benefits as a first-line treatment for uHCC, but its cost effectiveness remains unknown in the USA.

Objective: We aimed to assess the cost effectiveness of STRIDE (tremelimumab plus durvalumab) versus sorafenib and durvalumab monotherapy as the first-line treatment for uHCC in the USA.

Methods: A partitioned survival model was constructed to assess the cost effectiveness of STRIDE compared to sorafenib and durvalumab monotherapy as the first-line treatment for uHCC from the US societal perspective. The time horizon was 48 months with 1-month cycles. Seven parametric survival functions replicated survival curves from clinical trials, with the best-fitting model used to calculate survival probabilities. Costs, health utilities, and adverse events were included, with quality-adjusted life-years (QALYs) as the primary effectiveness measure. Both costs and effectiveness were discounted at 3%. In the base-case analysis, the incremental cost-effectiveness ratio was compared to a willingness-to-pay threshold of $150,000 per QALY gained. Deterministic and probabilistic sensitivity analyses were conducted to examine the uncertainty of the model.

Results: In the base-case analysis, STRIDE was cost effective compared to sorafenib, with an incremental cost-effectiveness ratio of $97,995.51 per QALY gained, based on a willingness-to-pay threshold of $150,000 per QALY gained. However, STRIDE was not cost effective compared to durvalumab monotherapy at the same threshold, with an incremental cost-effectiveness ratio of $754,408.92 per QALY gained. Deterministic sensitivity analyses were consistent with the base-case analysis. A probabilistic sensitivity analysis indicated that STRIDE was more likely to be cost effective than sorafenib and durvalumab monotherapy when the willingness-to-pay exceeded $101,000 and $713,000, respectively.

Conclusions: The STRIDE regimen appears to be cost effective compared to sorafenib but not compared to durvalumab for first-line uHCC treatment in the USA. However, durvalumab has not yet been approved for uHCC in the USA. Future research should focus on long-term data and economic evaluations of other recommended biologics.