Predictive and prognostic effect of ABO blood group on immune checkpoint inhibitors.

Background: The relationship of the ABO blood group system with the immune response is known, but its relationship with immune checkpoint inhibitors (ICIs) has not been clearly investigated until now.

Objective: In this study, the relationship between different blood groups and nivolumab treatment response in patients with advanced malignant melanoma was investigated.

Methods: The data of patients who used nivolumab for advanced malignant melanoma between April 2018 and April 2021 were retrospectively reviewed.

Results: A total of 73 patients were included in the study. In the progression-free survival (PFS) analysis according to blood groups, it was 3.9 months, 16.1 months, 20.0 months and 3.0 months for A, B, AB and O, respectively (p= 0.1). Overall survival (OS) analysis according to blood groups was 5.1 months, 25.0 months, 20.0 months and 9.3 months for A, B, AB and O, respectively (p= 0.1). The B antigen group (B or AB) had significantly longer PFS and OS than the non-B antigen group (A or O) (16.1 vs. 3.5 months for PFS, respectively, p= 0.03; 20.0 vs. 7.4 months for OS, respectively, p= 0.02).

Conclusions: The presence of B antigen provides a significant advantage in terms of survival in patients using ICIs for advanced melanoma.