Real-World Data on Clinical Outcomes and Treatment Management of Advanced Melanoma Patients: Single-Center Study of a Tertiary Cancer Center in Switzerland.

BACKGROUND: Immune checkpoint inhibitors (ICIs) and BRAF/MEK inhibitors (BRAF/MEKi) have drastically changed the outcomes of advanced melanoma patients in both the resectable/adjuvant and unresectable/metastatic setting. In this follow-up analysis of real-world data, we aimed to investigate the clinical management and outcomes of advanced melanoma patients in a tertiary referral center in Switzerland approximately a decade after the introduction of ICIs and BRAF/MEKi into clinical use. Moreover, we aimed to compare the results with seminal phase 3 trials and to identify areas of high unmet clinical need.

METHODS: This single-center retrospective cohort study analyzed the melanoma registry of the University Hospital Zurich, a tertiary cancer center in Switzerland, and included patients treated in the resectable/adjuvant (n = 331) or unresectable/metastatic setting (n = 375).

RESULTS: In the resectable setting, adjuvant anti-PD1 or BRAF/MEKi showed a 3-year relapse-free survival (RFS) of 53% and 67.6%, respectively, and the overall median RFS was 50 months. Patients with lymph node plus in-transit metastases or with distant metastases prior to commencing adjuvant treatment had a significantly reduced overall survival (OS). In 10.9% of patients, the treatment was stopped due to toxicity, which did not affect RFS/OS, unless the duration of the treatment was <3 months. Following a relapse of the disease during the first adjuvant treatment, the median progression-free survival (PFS2) was only 6.6 months; outcomes were particularly poor for relapses that were unresectable (median PFS2 3.9 months) or occurred within the first 2 months (median PFS2 2.7 months). A second adjuvant treatment for patients with resectable relapses still showed efficacy (median RFS2 43.7 months). Elevated LDH levels in patients with an unresectable relapse was correlated with a strong reduction in OS2 (HR 9.84, p = 0.018). In the unresectable setting, first-line anti-PD1, anti-CTLA4/PD1 combination, or BRAF/MEKi showed a 5-year OS of 46.5%, 52.4%, and 49.2%, respectively. In a multivariate analysis, elevated LDH levels or the presence of brain metastases substantially shortened OS (HR > 1.78, p < 0.035). There was a non-significant trend for the improved survival of patients treated with anti-CTLA4/PD1 compared to anti-PD1 (HR 0.64, p = 0.15). After a progression on first-line therapy, the median OS2 was reduced to below two years. Elevated LDH (HR 4.65, p < 0.001) levels and widespread disease with at least three metastatic sites, particularly bone metastases (HR 2.62, p = 0.026), affected OS2.

CONCLUSION: Our study offers real-world insights into the clinical management, treatment patterns, and outcomes of advanced melanoma patients in both the adjuvant and unresectable setting. Early relapses in patients undergoing adjuvant treatment pose a particular challenge but these patients are generally excluded from first-line trials. The approved first-line metastatic treatments are highly effective in the real-world setting with 5-year OS rates around 50%. However, outcomes remain poor for patients with brain metastases or who fail first-line treatment.