OBJECTIVES: Despite high unmet medical need and risk of recurrence for patients with resected Stage IIB/C melanoma, little is known about their PRS outcomes. This study analyzed individual-level patient data derived from nationwide, retrospective, longitudinal electronic health records to generate long-term PRS projections for Stage IIB/C melanoma patients in RW settings in the US.

METHODS: Recurrent patients with Stage IIB/C melanoma who had no adjuvant therapy after resection in the Flatiron Health Advanced Melanoma Cohort between 2011-2021 (inclusive) were analyzed. Time from first recurrence to death and time from first locoregional recurrence (LR) to a subsequent, more severe event (distant recurrence or death) were modeled separately using standard parametric distributions and spline-based models. For each endpoint, model selection was guided by commonly used statistical fit criteria and visual fit to the observed Kaplan-Meier curves. Medium and long-term rates of stay in recurrence and LR states as well as mean PRS and mean length of stay in LR state over a 40-year time horizon were examined across selected models.

RESULTS: Among all patients (n=602, mean age = 67), 67.9% were male, 59.1% were Stage IIB and 85.9% were white. Estimated PRS rates by year 5, 10 and 20 ranged between 37.3%-37.9%, 23.4%-24.7% and 11.8%-14.4%, respectively. Estimated mean PRS ranged between 7.5 – 8.34 years. Among patients with an initial LR (n=249, mean age = 67), 64.7% were male, 62.7% were Stage IIB and 86.7% were white. Estimated proportion of patients remaining in LR by year 5, 10 and 20 ranged between 27.6%-29.3%, 13.1%-15.8% and 4.9%-7.3%, respectively. Estimated mean time spent in LR was between 4.97 – 5.71 years.

CONCLUSIONS: Findings highlight the unmet need for effective adjuvant treatments for patients with Stage IIB/C melanoma and can assist the differentiation of their long-term PRS profiles with respect to recurrence type in RW settings.