Abstract 852P
Background
Immune checkpoint inhibitors (ICI) are current standard in treating metastatic melanoma. In melanoma, males are known to have a poorer prognosis compared to females. However, metanalysis have shown conflicting results regarding differences in ICI efficacy between females and males. In this study, we evaluate the efficacy of ICI in a real-world Danish metastatic melanoma population according to sex. The primary endpoint was progression-free survival (PFS). Secondary endpoint was overall survival (OS) and melanoma specific survival (MSS).
Methods
All patients treated with ICI (anti-PD-1 and/or anti-CTLA4) for metastatic melanoma in Denmark between 2011-2021 were identified in the Danish metastatic melanoma database. Only patients receiving ICI as first-line treatment were included. Baseline characteristics were evaluated according to ICI treatment for; age, ECOG performance status, lactate dehydrogenase (LDH), M-stage, BRAF status, the origin of melanoma (cutaneous or unknown primary melanoma), and granulocytes. Parameters for multivariate analysis were selected backwards, with a cutoff at 0.10.
Results
1461 patients; 573 females and 888 males were identified. Baseline characteristics were significantly unbalanced between sex. A higher frequency of BRAF mutation and a lower age was found for females, however, also elevated LDH and advanced M stage. The median follow-up time for PFS was 51 months (95% CI 48-55). Multivariate analysis showed sex as a significant factor of efficacy with improved PFS for females (HR 1.16 (1.02-1.33), p=0.03). Females showed significantly better OS with a five-year survival of 46% (41%-51%) for females and 38% (34%-42%) for males. Multivariate analysis reinforced this significance with HR 1.29 (1.09-1.52). Five-year MSS rates were 49% (95% CI 44%-54%) for female and 45% (40%-49%) for male. Multivariate analysis showed significantly better MSS for females (1.20 (1.01-1.43), p=0.04).
Conclusions
This study represents a complete, national dataset of ICI-treated metastatic melanoma patients. Baseline characteristics were unbalanced between sexes. Despite adjustments for clinical, validated prognostic factors, sex remains an independent prognostic factor for PFS, OS, and MSS in this real-world cohort.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Danish metastatic melanoma database (DAMMED).
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.