Background and importance The delopment of immuno-related adverse events (irAE) might be associated with better outcomes in oncological patients treated with immunotherapy.

Aim and objectives The main aim was to study the association between irAE incidence and the effectiveness of ipilimumab in monotherapy for patients diagnosed with locally advanced or metastatic melanoma. The secondary objectives were to analyse and to describe the incidence of irAE.

Material and methods Retrospective, observartional and longitudinal study in a tertiary care hospital which included every patient diagnosed with advanced melanoma initiating treatment with ipilimumab in monotherapy between February 2015 and December 2020. Follow-up was carried out until March 2021 or death for every patient receiving at least two cycles. The variables studied were: sex, age, disease record, location and histology of primary tumour, staging, functional status according to the Eastern Cooperative Oncology Group (ECOG), metastasis, mutational status of BRAF gene, treatment duration, reason for treatment suspension, and irAE appearance as well as its gravity according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Statistical analysis was carried out with Stata version 16. Effectiveness was measured as overall survival (OS) and it was calculated by Kaplan–Meier estimation. Survival curves were compared by log-rank test.

Results 39 patients were included, most of them men (64.1%) with a median age of 61 (54–72.5) years. 97.4% had an ECOG score between 0 and 1. 59.0% of patients suffered at least one irAE during follow-up. OS median for patients without irAE was 8.7 months. In the group that suffered one irAE, it was 21.8 months and in the group with two or more 13.1 months. Hazard ratio was 0.596 (95% CI 0.296 to 1.200).

Classification of irAE was as follows: 43.5% cutaneous, 26.1% gastrointestinal, 17.4% hepatobiliary and 13% other. Median OS for patients with irAE with severity degree 1 was 5.3 months, for the group with severity degree 2 it was in 27.1 months and for the group with severity degree 3 it was 13.1 months.

Conclusion and relevance In our patients, the development of irAE was associated with higher OS. More studies are needed in order to elucidate if these results are significant.

Conflict of interest No conflict of interest