Neoadjuvant Immune Checkpoint Inhibitor Therapy in Melanoma: Efficacy, Safety and Timing.

The introduction of effective systemic therapies has significantly changed the treatment of stage III and IV melanoma. Both immune checkpoint inhibitors and targeted therapies have improved recurrence-free survival in the adjuvant setting. Recent interest has sparked for neoadjuvant systemic therapy with immune checkpoint inhibitors. The intended benefit of pre-operative treatment with immunotherapy is amongst others to enable tailoring of the surgery and adjuvant systemic therapy according to the treatment response. Most importantly, recurrence-free survival might be improved by neoadjuvant systemic therapy over the current standard of care of surgery followed by adjuvant systemic therapy. The first phase I and II trials investigating anti-PD1 inhibitors, both as a single agent and in combination with anti-CTLA-4 inhibitors or other therapeutic agents, have shown promising results. Pathological complete response on neoadjuvant systemic therapy seems a valid surrogate endpoint for relapse-free and overall survival. Pathological complete response rates in these trials vary between 30 and 70%. The optimal dose with respect to efficacy and toxicity and the interval between systemic and surgical treatment remain important issues to address. Accumulating follow-up data and ongoing phase III studies must prove if neoadjuvant systemic therapy is superior to surgery followed by standard-of-care adjuvant therapy.