Neo-Adjuvant Therapy for Metastatic Melanoma.

Simple Summary: Neo-adjuvant systemic (NAS) therapy for melanoma is leading the way in immunotherapy for oncology. There is both a strong biological rationale to support NAS therapy, as well as exciting results in terms of superior efficacy to the current standards of care. Simply giving pembrolizumab 3 doses prior to surgery and 14 after rather than all 17 courses as adjuvant therapy only, demonstrated a 23% improvement in event-free survival (EFS). Combination immunotherapy with ipilimumab and nivolumab seems even more potent with ~60% of patients achieving Major Pathologic Responses (MPR) vs. ~25–30% for single agent anti-PD-1. NAS therapy will allow for a tailored approach to the therapy of melanoma patients, which includes a potential safe de-escalation of the extent of surgery and discontinuation of systemic therapy for MPR patients. And early identification of non-responders who can be directed towards clinical trials with novel therapies. These developments are now splashing over to other solid tumors, but there is still a need to develop a bespoke panel of biomarkers to further improve upon the current treatments. NAS therapy will soon become the novel standard of care approach for macroscopic stage III melanoma. Melanoma treatment is leading the neo-adjuvant systemic (NAS) therapy field. It is hypothesized that having the entire tumor in situ, with all of the heterogeneous tumor antigens, allows the patient's immune system to have a broader response to the tumor in all its shapes and forms. This translates into a higher clinical efficacy. Another benefit of NAS therapy potentially includes identifying patients who have a favorable response, which could offer an opportunity for the de-escalation of the extent of surgery and the need for adjuvant radiotherapy and/or adjuvant systemic therapy, as well as tailoring the follow-up in terms of the frequency of visits and cross-sectional imaging. In this paper, we will review the rationale for NAS therapy in resectable metastatic melanoma and the results obtained so far, both for immunotherapy and for BRAF/MEKi therapy, and discuss the response assessment and interpretation, toxicity and surgical considerations. All the trials that have been reported up to now have been investigator-initiated phase I/II trials with either single-agent anti-PD-1, combination anti-CTLA-4 and anti-PD-1 or BRAF/MEK inhibition. The results have been good but are especially encouraging for immunotherapies, showing high durable recurrence-free survival rates. Combination immunotherapy seems superior, with a higher rate of pathologic responses, particularly in patients with a major pathologic response (MPR = pathologic complete response [pCR] + near-pCR [max 10% viable tumor cells]) of 60% vs. 25–30%. The SWOG S1801 trial has recently shown a 23% improvement in event-free survival (EFS) after 2 years for pembrolizumab when giving 3 doses as NAS therapy and 15 as adjuvant versus 18 as adjuvant only. The community is keen to see the first results (expected in 2024) of the phase 3 NADINA trial (NCT04949113), which randomized patients between surgery + adjuvant anti-PD-1 and two NAS therapy courses of a combination of ipilimumab + nivolumab, followed by surgery and a response-driven adjuvant regimen or follow-up. We are on the eve of neo-adjuvant systemic (NAS) therapy, particularly immunotherapy, becoming the novel standard of care for macroscopic stage III melanoma. [ABSTRACT FROM AUTHOR]