OBJECTIVES

Treatment options for chemotherapy refractory metastatic colorectal cancer (mCRC) are relatively limited. Third-line systemic therapy options are currently restricted to regorafenib and TAS-102 (trifluridine/tipiracil), with selective internal radiation therapy (SIRT) providing another option for patients with liver dominant or liver limited metastases. The objective of the present analysis was to evaluate the cost-utility of SIRT with SIR-Spheres Y-90 resin microspheres relative to best supportive care (BSC) in the treatment of chemotherapy refractory mCRC from the perspective of the UK national healthcare payer.

METHODS

A cost-utility model was developed, utilizing a three-state Markov model structure to capture the progression of mCRC from progression-free survival to post-progression survival and death, informed by data from a retrospective cohort study of 224 patients with chemotherapy refractory mCRC. UK-specific unit costs were obtained from the literature, the British National Formulary, and National Health Service (NHS) England reference costs. Future costs and effects were discounted at 3.5% per annum over a lifetime time horizon. Probabilistic sensitivity analysis (PSA) and one-way sensitivity analyses were conducted, including an analysis in which SIRT work-up and procedure were conducted the same day with transradial access.

RESULTS

In the base case analysis, SIR-Spheres Y-90 resin microspheres resulted in an increase of 0.81 quality-adjusted life years (QALYs) from 0.69 QALYs with BSC to 1.50 QALYs. The improvement was accompanied by an increase in cost from £15,268 to £34,168, resulting in an incremental cost-utility ratio (ICUR) of £23,435 per QALY gained. With same-day transradial procedures, the ICUR decreased to £20,841. PSA reported a 96% likelihood of SIR-Spheres Y-90 resin microspheres being cost-effective versus BSC at a willingness-to-pay threshold of £50,000 per QALY gained.

CONCLUSIONS

SIR-Spheres Y-90 resin microspheres are a cost-effective treatment option compared to BSC for patients with liver-dominant colorectal metastases from the perspective of a UK national healthcare payer.