CN1 - Economic Guidance Panel Changes to Minimize Post-Progression Treatment Effects by the Pan-Canadian Oncology Drug Review in Economic Evaluations Assessing Cancer Drugs

Abstract

Progression-free survival (PFS) and overall survival (OS) are two common endpoints in cancer trials. OS is usually preferred, because it is reliable, precise, meaningful, and can easily be documented. When modelling OS in economic evaluations of cancer drugs, duration of treatment effect is largely unknown, and often is modelled by extrapolating OS data over the entire time horizon. This study examined the impact of modelling sustained treatment effect beyond progression on oncology reimbursement recommendations made by CADTH’s pan-Canadian Oncology Drug Review (pCODR). All publicly available pCODR final recommendation reports were identified from 1 January 2016 to 31 December 2017 from which dates, decisions, appraisal outcomes, clinical endpoints, and incremental cost-effectiveness ratios (ICERs) were extracted. Forty-one recommendations were issued by pCODR; 27 (66%) were positive (ie, with/without criteria/conditions) and 14 (34%) were negative. In approximately 25% of the recommendations, pCODR highlighted, as limitations with the submitted economic evaluations, improvement in life expectancy after treatment curtailment, and incremental clinical gains in the post-progression health state despite a lack of trial data to support these assumptions. To address these uncertainties, pCODR Economic Guidance Panel (EGP) made the following changes to the submitted economic models: truncating the model time horizon, assuming same mortality rate in the post-progression state, using a different parametric curve for the modelling of OS, truncating duration of treatment effect, and/or assuming an OS hazard ratio of 1 after the trial end date. These parameters had a significant impact on the ICERs. This study highlights that modelling treatment benefits on OS post-progression or beyond the trial end date, without evidence to support these assumptions will be subject to re-analysis by the EGP, which can have a significant impact on the ICERs.