Analysis of serum immune biomarkers for response to therapeutic personalized peptide vaccination in patients with metastatic breast cancer

Purpose: Our results from the previous clinical trials using personalized peptide vaccines (PPV) combined conventional chemo-hormonal therapies have confirmed the potential for clinical benefit in patients who had higher IgG antibody and/or CTL response to the immunized PPV (SABCS 2018 U Toh etc.). The aim of this study is to evaluate the association between the serum immunologic factors including cytokines, haptoglobin (HP), B-cell activating factor (BAFF) etc. and the clinical outcome of patients(pt) with metastatic breast cancer (mBC) who treated by personalized peptide vaccines (PPV). Methods: Peripheral blood samples from 57 pts and 52 pts obtained before and after the vaccination of PPV, respectively. Serum HP and IL-6 were analyzed by ELISA(RD p=0.015;0.068;0.002, respectively). There was no difference in high BAFF, low IFN-γ or high IL-8 level group(n=29). In contrast, pt’s group with low serum level of IL-10, GM-CSF, IL-5, IL-4 and low HP level ( Citation Format: Uhi Toh, Shuko Saku, Yuko Takao, Sayaka Sakurai, Miki Takenaka, Shigeki Shichijo, Kyogo Itoh, Yoshito Akagi. Analysis of serum immune biomarkers for response to therapeutic personalized peptide vaccination in patients with metastatic breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-04-21.