Presentation (CTI)

OBJECTIVES: To estimate the efficacy and pricing requirements for a hypothetical HER2-targeted therapy ("Drug X") to achieve cost-effectiveness relative to pertuzumab, trastuzumab and docetaxel (PTD) in first-line HER2-positive metastatic breast cancer (mBC) from an NHS England perspective.
METHODS: A partitioned survival model was developed to compare PTD with trastuzumab plus docetaxel (TD) over a lifetime horizon. Health states included progression-free disease, progressed disease and death. Costs and outcomes were discounted at 3.5% annually. Clinical efficacy was informed by published trial data and extrapolated using parametric survival models. A threshold analysis was subsequently undertaken in which Drug X was compared against PTD. Drug X acquisition cost (£1,000-£4,000 per cycle) and treatment effect (overall survival [OS] and progression-free survival [PFS] hazard ratios [HRs] between 0.40 and 1.00) were varied to identify combinations capable of achieving more favourable cost-effectiveness than PTD.
RESULTS: In the base case, PTD generated 3.09 discounted quality-adjusted life-years (QALYs) compared with 2.36 QALYs for TD, providing an incremental gain of 0.73 QALYs. Incremental costs were £128,145, resulting in an incremental cost-effectiveness ratio (ICER) of £175,474/QALY. Following application of a 42% patient access scheme discount, the pertuzumab ICER decreased to £59,101/QALY (£34,765/QALY when applying a severity modifier). Threshold analyses demonstrated that Drug X could achieve substantially lower ICERs than PTD across a broad range of price-efficacy combinations. At a treatment cost equivalent to pertuzumab list price (£2,395 per cycle) and HRs of 0.75 for both OS and PFS, Drug X generated an ICER of £1,421/QALY versus PTD. Greater survival benefits expanded the range of prices at which Drug X remained attractive.
CONCLUSIONS: Threshold analyses provide a framework for quantifying the clinical benefit and pricing required for novel therapies to compete with established standards of care. In HER2-positive mBC, survival gains can offset higher acquisition costs and support favourable cost-effectiveness relative to PTD.