“It's not just what you give, it's when you give it! SWOG S1801 demonstrates that the same treatment for resectable melanoma given in a different sequence can generate lower rates of melanoma recurrence.” said study first author Sapna Patel, The University of Texas MD Anderson Cancer Center, Houston, USA.

“In this case, we used the immune checkpoint inhibitor pembrolizumab. This treatment relies on the presence of pre-existing T cells that encounter cancer cells to generate a larger immune response before the melanoma is removed, and with it the bulk of tumor-specific T cells thrown away, than if given after surgery. Our study noted an improvement in event-free survival in the neoadjuvant arm compared to the adjuvant arm. Importantly, a similar number of patients in both arms experienced events before initiating adjuvant pembrolizumab, but the rate of events after adjuvant therapy was higher (worse) in the adjuvant arm. The findings from S1801 have important implications about the sequence of treatment for patients with melanoma and other cancers that respond to immune checkpoint blockade.”

Contextualising the results of the study, Marco Donia, National Center for Cancer Immune Therapy (CCIT-DK), Copenhagen University Hospital, Herlev, Denmark, not involved in the study, said: “Neo-adjuvant immunotherapy (NAT) in resectable melanoma is particularly intriguing. Stimulating a patient’s immune response to intact tumours may benefit from a more natural immunological milieu and improved tumour-antigen presentation. This strategy is being evaluated in multiple clinical trials and settings where available treatments are used in a different sequence than the current standard.”

With regards to the results, Donia added: “SWOG S1801 shows that NAT followed by surgery is a safe and feasible strategy. CPR rates are similar to those previously observed in a similar setting, and not distant from the CR rates observed in the metastatic setting with anti-PD-1 monotherapy. The early improvement of EFS with NAT compared to AT is highly promising. Overall, these early positive results warrant further OS follow-up and additional phase 3 investigations to understand whether NAT is a new standard of care for patients with stage IIIB-IV resectable melanoma. Positive results may lead to the implementation of NAT straight away.”

Source: ESMO