292 Is it safe to discontinue immunotherapy after a response in merkel cell carcinoma?

Immunotherapy (IMTX) has significantly improved outcomes for patients with advanced Merkel cell carcinoma (MCC). However, data on the durability of response after IMTX discontinuation is limited. We retrospectively assessed 170 persons with advanced MCC treated with a first-line anti-PD-(L)1 agent to determine recurrence rates in patients who discontinue IMTX after complete (CR) or partial (PR) responses to therapy. Reasons for discontinuation were classified as elective or due to toxicity. Of 170 patients, 104 (61%) had objective responses and 66 (39%) did not.