Changes in the survival of adult patients with metastasized melanoma with the approval of immune checkpoint inhibitors: A retrospective study from the United States database

Background: Immune-checkpoint inhibitors (ICI) have revolutionized the treatment of metastatic melanoma. Ipilimumab and Ipilimumab-Nivolumab combination therapies were approved by the United States Food and Drug Administration in 2011 and 2015, respectively. We aimed to evaluate potential changes in the survival of patients with metastatic melanoma following the approval of these agents. Methods: We extracted data from the Surveillance, Epidemiology, and End Results (SEER) database (Nov 2021 submission). All patients aged 20 and above who were diagnosed with ‘distant’ melanoma (per ‘combined summary stage’) from 2007 through 2018 were included in the study. This time period was further sub-categorized into 2007–2010 (pre-ICI era), 2011–2014 (single-agent ICI era), and 2015–2018 (combination ICI era) based on the approval timeline of ICI. Results: The median overall survival (OS) was 8, 10, and 14 months in the pre-ICI, single-agent ICI, and combination ICI eras respectively (log-rank test, χ² = 189.03, p < 0.001). On Cox-proportional hazard analysis, patients diagnosed in the single-agent and combination ICI eras had a significantly lower risk of dying [HR 0.82 (95% CI 0.78–0.87) and 0.67 (0.64–0.71), respectively] compared to patients diagnosed in the pre-ICI era. Patients who were of the male gender, aged ≥ 65 years, and those receiving chemotherapy and/or radiotherapy were at a significantly higher risk of dying. Married individuals had a significantly lower risk of dying compared to patients who were divorced, separated, or widowed at the time of diagnosis. There was no significant difference in survival demonstrated among non-Hispanic blacks versus non-Hispanic whites. Conclusion: Survival of patients with metastatic melanoma has improved in the era of immune checkpoint inhibitors. It implies that the survival of patients reported in trials can be correlated at a population level as well. Future analysis from the SEER database is needed when new data becomes available to see if there is a further increase in OS.