OBJECTIVES : The development of immunotherapies (IOs) for the treatment of bladder cancer in first and second-line, namely pembrolizumab and atezolizumab, increased the economic burden of this disease.The objective is to use an economic model to compare the additional cost when IOs are included in treatment algorithm of metastatic bladder cancer

METHODS : The model evaluated overall survival (OS), progression-free survival and costs associated with each drug; adverse event (AE) treatment; monitoring; and post-progression (third-line treatment, best supportive care). Efficacy, safety, and treatment duration were estimated from regimens’ pivotal clinical trials. The model included first-line gemcitabine-cisplatin (Gem-Cis), gemcitabine-carboplatin (Gem-Carb) or IOs in Cis-ineligible patients and high PD-L1 expression, and second-line IOs, Gem-Carb, paclitaxel or docetaxel. Cost of BSC and AEs was retrieved from published Canadian studies. Sensitivity analyses were conducted to take in consideration potential rebates to IOs in hospital

RESULTS : The cost of treating patients with Gem-Cis was estimated to be $24,117 with 36% of cost related to the management of adverse events. When treating patients in second-line setting, the incremental survival of atezolizumab, paclitaxel and docetaxel compared to pembrolizumab was 0.8, -3.3 and -3.3 months, respectively. Treatment with second-line therapy costs $64,207, $54,857, $14,119 and $14,154 for pembrolizumab, atezolizumab, paclitaxel and docetaxel, respectively. Cost of managing adverse events represented less than 1 % for IOs and 10% for paclitaxel/docetaxel. In Cis-ineligible patients, the use of IOs in first-line increased cost by $47,818 (total $72,596) vs. Gem-Carb, while improving OS by 6.6 months

CONCLUSIONS : In a Canadian setting, inclusion of IOs in the management of metastatic bladder cancer as first- or second-line therapy will increase treatment cost by approximately $50,000 for an incremental survival of 3 to 6 months