438P - Real-world data of relapse after adjuvant treatment (Tx) in high-risk melanoma

Background

Adjuvant (adj) Tx with programmed cell death protein 1 (PD-1) inhibitors or targeted therapy (TT) for 1 year in patients (pts) with high-risk resected melanoma prolongs relapse-free survival (RFS). However, up to 1/3 of pts recur in the year after adj Tx and there are few data regarding patterns of relapse, management and outcomes. Our aim was to describe how adj Tx impacts the outcomes in melanoma pts in our center.

Methods

Single-institution experience of 123 consecutive pts with melanoma resected in our center from 2014 to 2019 were retrospectively analyzed. Clinicopathological factors, adj Tx, timing and patterns of relapse, Tx at relapse and subsequent outcomes were examined.

Results

Median age at diagnosis was 57 years, 45% were male and BRAF-mt was found in 38%. Stage III A/B/C/D or IV was 6%, 10%, 19%, 1% and 1%, respectively. Sentinel node biopsy was performed in 80% and lymphadenectomy in 33% of 123 pts. A total of 49 pts received adj Tx: 3 pts (6%) TT, 8 pts (16%) IFN-α, and 38 pts (31%) immunotherapy (iTx) with anti-PD-1 and/or ipilimumab. A total of 40 pts (32%) had relapse (65% locoregional and 35% distant), 8 pts (21%) had prior adj iTx with a median RFS of 21.5 months (m) (CI95%17.4-NA). 24 pts (60%) were resected (6 pts with distant recurrent), 14 pts received adj Tx (12 pts iTx, 1 pt IFN-α and 1 pt TT), for 4-pts was the second adj Tx. A total of 31 of 123 pts (25%) developed metastatic melanoma (MM), of these 17 pts (55%) received adj Tx. PFS at 1^st line of Tx of pts with prior adj-Tx vs no was similar (HR=1.01, p=0.98), mainly Tx were iTx (65%), TT (31%) and chemotherapy (4%). Remarkably, there was no worse response rate (complete response [CR] or partial response [PR]) in pts with prior adj Tx (68.8% vs 35.7%, p=0.14). Of 17 pts with prior adj-Tx (16 pts adj-iTx) who had MM, twelve (70.6%) received iTx at 1^st line, 50% had response to iTx. Also, all 4 pts BRAF-mt with prior adj iTx who received TT at 1^st line had CR or PR. There was no correlation between treatment-free interval after adj TX and PFS at 1^st line (p=0.66).

Conclusions

Our real-world data demonstrates that after a locoregional or distant relapse of melanoma, despite prior adj-Tx, Tx with iTx or TT can be active. But additional research is needed.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

R. Dienstmann: Advisory/Consultancy: Roche, Boehringer Ingelheim; Honoraria (self): Roche, Ipsen, Amgen, Servier, Sanofi, Merck Sharp & Dohme; Research grant/Funding (self): Merck, Pierre Fabre. E. Muñoz-Couselo: Advisory/Consultancy: BMS; Advisory/Consultancy: Novartis; Advisory/Consultancy: Roche. All other authors have declared no conflicts of interest.