To-date, PD-1 inhibitors have been given to patients with melanoma continuously (non-stop), for as long as they remain beneficial, for up to a total duration of 2 years. The 2 year duration was chosen because doctors thought it was reasonable, and has been adopted as the standard or usual duration because it was shown to work in clinical trials. However, some recent observations suggest that PD-1 inhibitors may work just as well if they are given for a shorter time and/or in an intermittent schedule. Intermittent means to take breaks from receiving the drug when, and for as long as, the melanoma is better.