Immune checkpoint inhibitor treatment - real-world use and outcomes in Sweden 2015-2023.

BACKGROUND: The introduction of immune checkpoint inhibitor (ICI) treatment has significantly improved the treatment of several cancer diagnoses, such as non-small cell lung cancer, renal and urothelial carcinoma, melanoma. However, there is a lack of real-world data on ICI treatment and outcomes from the Swedish healthcare setting. The cost of treatment is also significant, and securing equal access to emerging drugs for all patients is challenging in an era of rapidly evolving treatment recommendations. METHODS: We conducted a population-based observational study of incident cases among ICI-treated patients, using a novel electronic healthcare record source for systemic cancer drugs linked to regional and national register data. Overall survival (OS) was calculated from start of the first ICI-treatment, using the Kaplan-Meier method. The aim was to examine treatment with ICI drugs during 2015-2023 in 10 Swedish regions (total population 4.3 million). RESULTS: Median real-world OS was 2.0 years (95% confidence interval: 1.8-2.2 years) from start of ICI-treatment for patients with known palliative treatment intent (n = 1,941, lung 2.2 years, melanoma 5.0 years, renal 2.3 years, urothelial 1.1 years, head/neck 1.4 years).In 2023, 6.7% of all patients receiving systemic antineoplastic treatment for cancer were treated with ICI (74 per 100,000 inhabitants). The timing of the adoption of treatment with ICI drugs and the current patterns of use differed between Swedish regions. CONCLUSION: This study provides the first Swedish real-world OS estimates after ICI-treatment across major diagnoses, documents the rapidly increasing ICI use, and describes regional variation in treatment patterns.