Three years after starting anti-PD-1 therapy, most patients who have complete response maintain that status despite stopping their treatment.

A real-world study of US patients with advanced melanoma shows that complete response can be maintained for 21 months without further anti-PD-1 therapy but reveals “disappointing” results for patients who relapse and are retreated.

The analysis of data from 396 patients with unresectable stage III or stage IV melanoma, at the Memorial Sloane Kettering Cancer Centre in New York City, New York, includes some of the longest patient follow-ups to date and also provides data on the biggest cohort yet undergoing retreatment with anti-PD-1s.

More than one-quarter of patients given anti-PD-1 therapy achieved a complete response after a median treatment duration of seven months on either nivolimumab or pembrolizumab, the authors wrote in the Journal of Clinical Oncology.