Importance: Treatment-free survival (TFS) represents an alternative time-to-event end point, accurately characterizing time spent free of systemic therapy, providing a more patient-centric view of immune checkpoint inhibitor (ICI) therapy regimens. There remains a lack of studies evaluating TFS outcomes among patients with advanced melanoma who are receiving immunotherapy, especially outside of the clinical trial setting.
Objective: To evaluate TFS outcomes for patients with advanced melanoma receiving first-line ICI therapy outside of a clinical trial setting.
Design, setting, and participants: This multicenter cohort study of patients with advanced melanoma receiving first-line ICI therapy between August 1, 2013, and May 31, 2020, was conducted in Alberta, Canada. Data analysis was performed in August 2022.
Exposures: Patients received standard-of-care, first-line ICI therapy treatment regimens including single-agent nivolumab, single-agent pembrolizumab, or ipilimumab-nivolumab.
Main outcomes and measures: Treatment-free survival was defined as the difference in the 36-month restricted mean survival time between 2 conventional survival end points: (1) time from treatment initiation to ICI cessation, death, or censoring at last follow-up and (2) time from treatment initiation to subsequent systemic anticancer therapy, death, or censoring at last follow-up.
Results: A total of 316 patients with advanced melanoma receiving first-line nivolumab (n = 51; median age, 66 years [IQR, 56-78 years]; 31 men [60.8%]), pembrolizumab (n = 158; median age, 69 years [IQR, 60-78 years]; 112 men [70.9%]), or combination nivolumab-ipilimumab (n = 107; median age, 53 years [IQR, 42-60 years]; 72 men [67.3%]) were included. Treatment groups were similar with regard to sex, primary tumor location, and presence of metastasis, although patients receiving combination nivolumab-ipilimumab had a lower Eastern Cooperative Oncology Group status, were younger, and were more likely to be BRAF V600E positive than those receiving anti-programmed cell death protein 1 (anti-PD-1) monotherapy. The restricted mean TFS was longer for nivolumab-ipilimumab (12.4 months [95% CI, 8.8-16.0 months]) compared with nivolumab (8.9 months [95% CI, 4.4-13.5 months]) and pembrolizumab (11.1 months [95% CI, 8.5-13.8 months]). During the 36-month follow-up interval, patients treated with nivolumab-ipilimumab spent 34.4% of their time (12.4 of 36 months) not receiving systemic anticancer treatments compared with 30.8% (11.1 of 36 months) and 24.7% (8.9 of 36 months) of the time for the pembrolizumab and nivolumab treatment groups, respectively.
Conclusions and relevance: This cohort study of patients with advanced melanoma receiving first-line ICI therapy suggests that TFS represents a patient-centric, informative end point. Patients treated with combination nivolumab-ipilimumab spent more time alive and free from systemic anticancer therapy than those treated with anti-PD-1 monotherapy alone.