Factors influencing the reimbursement decisions of cancer drugs in Spanish National Health System

OBJECTIVE: This study aims to evaluate the influence of several factors, including added clinical benefit, cost-utility, availability of therapeutic alternatives, innovation level, and evidence uncertainty, on public reimbursement decisions for cancer drugs targeting solid tumours in Spanish National Health System between 2010 and 2023. METHODS: 220 drug indications for solid tumours authorised between January 2010 and December 2023 were included. Clinical benefit was assessed using the European Society for Medical Oncology- Magnitude of Clinical Benefit Scale (ESMO-MCBS). Cost-utility was estimated based on pharmacological costs and Quality Adjusted Life Years (QALY), using data from Health Technology Assessment Agencies (HTAAs) reports and list prices. Other variables included innovation, presence of therapeutic alternatives, quality of clinical trial evidence, and availability of overall survival (OS) and quality of life data (QoL). This influence was also controlled for by the year of the reimbursement decision. Statistical analysis included descriptive statistics and several probit regression models to estimate the impact of each factor on reimbursement likelihood. RESULTS: Of the 220 indications analysed, 68.2% received public reimbursement. Substantial clinical benefit was observed in 50% of cases and was significantly associated with reimbursement (OR = 2.7, 95% CI: 1.4-5.3; p < 0.01). Median incremental cost-utility ratios (ICUR) were €86,770/QALY (list prices) and €47,190/QALY (reimbursed prices), with no significant differences between reimbursed and non-reimbursed indications. The probit results indicate that substantial clinical benefit significantly increases the probability of public reimbursement by between 17.5 and 20.1% points (pp). Another relevant factor is the absence QoL data, which decreases the probability of reimbursement by between 13.9 and 14.8 pp. Drugs with reimbursement decisions made between 2020 and 2023 had a 19.4 pp lower probability of being reimbursed. CONCLUSION: Substantial clinical benefit and absence of QoL uncertainty significantly increases the likelihood of public reimbursement for oncology drugs in Spain, while cost-utility estimates apparently show no influence under current decision-making processes. Decisions made between 2020 and 2023 had a lower probability of receiving public reimbursement compared to the 2010-2019 period possibly due to the accumulation of drugs approved by European Commission in recent years. These findings highlight the need for clearer integration of economic evaluations and transparent criteria as Spain updates its P&R framework.