Objective: Canadian Agency for Drugs and Technologies in Health (CADTH) has no established incremental cost-effectiveness ratio (ICER) threshold for reimbursement purposes. However, a willingness to pay (WTP) threshold of $50,000 per Quality Adjusted Life Year (QALY) is viewed favourably for both oncology and non-oncology products. We aimed to review the submissions of cancer drugs made to CADTH from January 2016 to June 2021, to understand the applicability of willingness to pay thresholds acceptable for CADTH.

Methods: Reimbursement review reports of oncology pharmaceuticals and oncology gene therapies were obtained from CADTH to extract data for clinical and economic evidence. Clinical benefit was calculated as an absolute gain in median progression free survival (PFS) and median overall survival (OS).

Results: A total of 128 unique submissions were identified. Of all submissions, 78 had a base-case ICER of >$50,000/QALY (median: $133,140/QALY) with a clinical benefit of 4.8 months of median OS gain and 7.1 months of median PFS gain for the drugs that reported the data. These drugs were recommended for reimbursement, conditional on cost-effectiveness being improved to an acceptable level. Of the drugs reporting data on price reduction with a base-case ICER of >$50,000/QALY (n=24), nearly 70% submissions were recommended based on a price reduction of at least 70% to meet the $50,000/QALY threshold. The price reductions were even higher for recently recommended drugs. Of all submissions, 24 with a base-case ICER of >$50,000/QALY (median: $171,086/QALY) were not recommended mainly due to lack of clinical benefit.

Conclusion: This analysis suggests that the WTP threshold used by CADTH is frequently leading to highly challenging implementation of economic recommendation for novel therapies in oncology. This highlights the limitations of the QALY/WTP threshold-based approach to effectively inform the decision-makers to optimally secure access for patients.