Neoadjuvant data in melanoma presented at The American Society of Clinical Oncology Symposium (ASCO) 2019 annual conference - prepared by Lewis Au of The Francis Crick Institute.

 

The American Society of Clinical Oncology Symposium (ASCO) 2019 annual conference was held in Chicago, USA in June 2019. As the largest oncology conference yearly, it was attended by over 40,000 researchers, clinicians, patient advocates and many others.

 

For melanoma research, the research presented this year was focused on refining our therapeutic approaches, rather than any practice changing trials data. Data were presented on biomarker research (to predict or track response to treatment), optimal therapy sequencing strategies, and importantly, ongoing work to find effective therapies for rare melanoma subtypes such as mucosal and uveal melanoma.

 

Perhaps the most exciting data came from a pooled analysis of six modern neoadjuvant systemic therapy (NST) studies with interesting results¹. Neoadjuvant therapy – or more specifically for this setting, use of immune checkpoint inhibitors or targeted therapies prior to surgical resection for stage III melanoma – is currently not yet a standard-of-care treatment option.

 

Pathological complete response (pCR; or nil further evidence of invasive tumour on histological assessment after NST) has been shown to correlate with improved survival in other tumour types. Menzies and colleagues have pooled the results for a metanalysis of 6 recent NST trials in melanoma evaluating anti-PD1 based immunotherapy or BRAF/MEK targeted therapies with in the International Melanoma Consortium (INMC) network. 184 patients with stage III (roughly 50% with stage IIIC and 50% with stage IIIB) melanoma who completed NST and underwent surgery were evaluated. Main question to answer if pCR rates following NST treatments in melanoma translates to clinical outcome benefits.

 

pCR was observed in 41% of patients. Median total follow-up was 13 months. Breaking down the results by classes of drugs received, 83% of patients who received immune checkpoint inhibitors remained relapse free (RFS) within the follow up period, while 45% treated with targeted therapies achieved RFS survival.

 

Strikingly, RFS rates for those with pCR after immunotherapy treatment was 100% (no patients relapsed) at 24 months (compared with those without pCR on histological assessment, with RFS rates of 72%). For those with pCR after targeted treatment, RFS was 78% (compared with 8% for those without pCR).

 

Overall, this is exciting data to conclude that drug treatment before surgery for high-risk stage III melanoma are active treatments, and that pathologic complete response where no viable tumours are present on histology review after treatment appears to correlate with better outcomes for patients.

 

Ongoing, larger, prospective studies are being conducted to confirm these findings.

 

1. Menzies AM, Rozeman EA, Amaria RN. Pathological response and survival with neoadjuvant therapy in melanoma: A pooled analysis from the International Neoadjuvant Melanoma Consortium (INMC).Presented at: 2019 American Society of Clinical Oncology (ASCO) Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract 9503. https://abstracts.asco.org/239/AbstView_239_259557.html