ISSUE: The cancer treatment landscape has been evolving with the introduction of products such as cell therapies that require higher upfront investment yet offer the potential for significant improvements in long-term health outcomes. These products often have trials with relatively short follow-up creating increased uncertainty around their long-term cost-effectiveness. With a growing need to balance the long-term effectiveness of these treatments with short-term affordability, payers are showing increased interest in innovative payment schemes, such as outcomes-based contracting, leveraging objective short-term outcomes to help balance the financial investment with the potential long-term benefits. HTA agencies are starting to discuss how appraisal frameworks need to be updated for cell and gene therapies, but the challenges of accounting for outcomes-based agreements in economic models for oncology products have not been explicitly defined.

OVERVIEW: Partitioned survival models have been the standard cost-effectiveness modelling approach in oncology in recent years, utilising data on disease progression and death directly from clinical trials. Innovative therapies offer the possibility of significant improvements in overall survival, and possibly even long-term cure; however, these benefits are often based on trials with short-term follow-up (<2 years) at the time of reimbursement assessment, with meaningful gains primarily demonstrated on surrogate endpoints like overall response rate. Given that a product’s cost-effectiveness and budget impact would be dependent on the reimbursement scheme, it may be appropriate to use shorter-term clinical outcomes, such as response rate, as the structural framework for models rather than survival. Do models need to explicitly account for the correlation between shorter-term outcomes that are metrics for reimbursement, and the longer-term drivers of cost-effectiveness, and capture the uncertainty in the relationship, in order to appropriately inform potential outcome-based agreements? This panel will discuss the potential modelling approaches, the results, their validity, and the implications for payers and HTA agencies.