1092P - Adjuvant treatment with anti-PD-1 in acral melanoma patients: A nationwide study

Background

Previous studies demonstrate limited efficacy of immune checkpoint inhibitors in patients with irresectable acral melanoma (AM) compared to cutaneous melanoma (CM) in other locations. However, little is known about the outcomes of adjuvant therapy for resectable stage III-IV AM. This study aims to compare clinical outcomes after treatment with adjuvant anti-PD-1 in resectable stage III-IV AM and compare them to CM.

Methods

All patients with stage III-IV AM and CM who received adjuvant anti-PD-1 after complete resection between 2017 and 2022 were included from the prospective nationwide Dutch Melanoma Treatment Registry. We described baseline characteristics and analyzed the recurrence-free survival (RFS). A multivariable Cox regression analysis was performed to account for potential confounders age, performance status (ECOG), AJCC 8th edition disease stage, mutation status. Type of recurrence (locoregional or distant metastases) and toxicity rates will be presented at the conference.

Results

In total, 1977 patients (86 AM and 1891 CM) were included. At baseline, KIT mutations were more common in AM patients. In addition, AM patients more often had higher AJCC 8 disease stages. No other significantly different baseline characteristics were identified. Median follow-up was 16.4 months. The median RFS was 14.8 months (95%CI: 11.5-29.7) for the AM cohort and 37.4 months (95%CI: 32.1 - NR) for the CM cohort (p=.002)). After correcting for potential confounders, AM remained associated with higher risk of recurrence than CM (HR_adj 1.55; 95%CI: 1.09-2.19; p=.014). Table: 1092P

Baseline characteristics and median RFS stratified by melanoma type.

Conclusions

This study suggests that AM patients treated with adjuvant anti-PD-1 have shorter RFS than CM patients receiving the same treatment. Longer follow-up is needed to investigate overall survival and distant-metastasis-free survival.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

J.B.A.G. Haanen: Financial Interests, Institutional, Advisory Board: Bristol Myers Squibb, Achilles Therapeutics, Ipsen, Merck Sharp & Dohme, Merck Serono, Pfizer, Molecular Partners, Novartis, Roche, Sanofi, Third Rock Venture, Iovance Biotherapeutics; Financial Interests, Institutional, Advisory Board, SAB member: BioNTech, Immunocore, Gadeta, Instil Bio, PokeAcel, T-Knife; Financial Interests, Personal, Advisory Board, SAB member: Neogene Therapeutics, Scenic; Financial Interests, Personal, Stocks/Shares: Neogene Therapeutics; Financial Interests, Institutional, Research Grant: Bristol Myers Squibb, BioNTech US, Merck Sharp & Dohme, Amgen, Novartis, Asher Bio; Non-Financial Interests, Member: ASCO, AACR, SITC; Other, Other, Editorial Board ESMO Open: ESMO; Other, Other, Editor-in-Chief IOTECH: ESMO; Other, Editorial Board: Kidney Cancer. C.U. Blank: Financial Interests, Institutional, Advisory Board: BMS, MSD, Roche, Novartis, GSK, AZ, Pfizer, Lilly, GenMab, Pierre Fabre; Financial Interests, Personal, Advisory Board: Third Rock Ventures; Financial Interests, Personal, Stocks/Shares: Immagene; Financial Interests, Personal, Stocks/Shares, intention to develop IFN signature algorithm: NewCo, no name yet; Financial Interests, Institutional, Coordinating PI: BMS, Novartis, NanoString, 4SC; Other, pending patent: WO 2021/177822 A1. M.J.B. Aarts: Financial Interests, Advisory Board: Amgen, BMS, Novartis, MSD-Merck, Merck-Pfizer, Pierre Fabre, Sanofi, Astellas, Bayer; Financial Interests, Institutional, Research Grant: Merck-Pfizer. J.W. de Groot: Financial Interests, Advisory Role: BMS, Pierre Fabre, Servier, MSD, Novartis. G.A.P. Hospers: Financial Interests, Advisory Role: Amgen, BMS, Roche, MSD, Pfizer, Novartis, Pierre Fabre; Financial Interests, Institutional, Research Grant: BMS, Seerave. E. Kapiteijn: Financial Interests, Institutional, Advisory Board: BMS, Novartis, Pierre Fabre, Merck, Delcath, Bayer, Lilly; Financial Interests, Institutional, Coordinating PI: BMS, Pierre Fabre, Delcath. R.S. van Rijn: Financial Interests, Advisory Board: Pfizer; Financial Interests, Other, expert meeting fee: Roche. A.A.M. Van der Veldt: Financial Interests, Institutional, Advisory Role: BMS, Roche, Novartis, Pierre Fabre, Pfizer, Sanofi, Ipsen, Eisai, Merck; Financial Interests, Institutional, Advisory Board: MSD. M.J. Boers-Sonderen: Financial Interests, Advisory Role: Pierre Fabre, MSD, Novartis. F. Van Den Eertwegh: Financial Interests, Institutional, Research Grant, Grant for national trial: Roche; Financial Interests, Institutional, Research Grant, Grant for research project: BMS; Financial Interests, Institutional, Research Grant, Research grant for trial: Sanofi, Idera; Financial Interests, Institutional, Research Grant, Grant for trial: Teva; Non-Financial Interests, Advisory Role: BMS, Novartis, Pierre Fabre, MSD, Pfizer, Amgen, Ipsen, Merck. K.P.M. Suijkerbuijk: Financial Interests, Institutional, Advisory Board: Novartis, BMS, AbbVie, Pierre Fabre, MSD; Financial Interests, Institutional, Invited Speaker: Roche; Financial Interests, Institutional, Research Grant: Novartis, TigaTx. All other authors have declared no conflicts of interest.