With extended follow-up, patients with advanced melanoma given nivolumab plus ipilimumab were shown to have a treatment-free survival (TFS) twice as long as those given nivolumab monotherapy, according to data presented at the virtual 2020 ASCO Annual Meeting.

“We previously defined a novel outcome, TFS, to characterize the time between immune-checkpoint inhibitors (ICI) therapy cessation and subsequent therapy initiation/death,” explained Meredith M. Regan, ScD, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, and co-investigators.

In 2019, Dr Regan et al reported on the TFS of ICI-treated patients with advanced melanoma in the 36 months after randomization in the phase 3 CheckMate-067 trial. At the virtual meeting, they presented TFS data for 937 patients in CheckMate-067 in the 60 months post-randomization.

According to Dr Regan and colleagues, TFS was the area between the Kaplan–Meier curves for 2 conventional time-to-event end points defined from randomization (ie, time to protocol therapy cessation and time to subsequent therapy/death).

In addition, the TFS was divided based on whether or not patients had grade ≥3 treatment-related adverse events.

Over the course of 60 months, patients given nivolumab plus ipilimumab, nivolumab, and ipilimumab spent an average of 33%, 17%, and 20% of time free of treatment, respectively (r-mean TFS, 19.7, 9.9, and 11.9 months, respectively).

Patients who received nivolumab plus ipilimumab had an r-mean TFS 9.8 months longer than that of nivolumab-treated patients (95% CI, 6.7-12.8) and 7.8 months longer than that of ipilimumab-treated patients (95% CI, 4.6-11.0).

The mean rate of patients with TFS and grade ≥3 treatment-related adverse events was small across the 60-month period, at 3%, 2%, and <1% for patients given nivolumab plus ipilimumab, nivolumab, and ipilimumab, respectively.

“With extended follow-up, average TFS with/without toxicity represented greater percentages of the 60-month vs 36-month period for nivolumab plus ipilimumab and nivolumab, but not for ipilimumab,” Dr Regan and colleagues wrote.

“Patients treated with nivolumab plus ipilimumab continued to have TFS twice as long as those treated with nivolumab alone, due to earlier therapy cessation for toxicity without disease progression and subsequent resolution of many of those toxicities,” they concluded.—Hina M. Porcelli

Regan MM, Mantia C, Werner L, et al. Estimating treatment-free survival (TFS) over extended follow-up in patients (pts) with advanced melanoma (MEL) treated with immune-checkpoint inhibitors (ICIs): Five-year follow-up of CheckMate 067. Presented at: the 2020 ASCO Annual Meeting; May 29-31, 2020. Abstract 10043.