Peptide Radio Receptor Therapy induces immune activation in patients with neuroendocrine tumors and might sensitize to immunotherapy

#3386

Introduction: Peptide Radio Receptor Therapy (PRRT) is a standard treatment in patients with neuroendocrine tumors (NET), but treatment responses are limited and novel therapy combinations are needed. Since radiation induced cell death is considered immunogenic, patients might benefit from a combination of PRRT with immunotherapies, such as immune checkpoint inhibitors (ICI).

Aim(s): We aim to characterize the peripheral immune cell compartment of patients with NET undergoing PRRT to better understand how PRRT might synergize with ICI and which patients could benefit from a combined therapy.

Materials and methods: Blood samples of 43 patients drawn before and after PRRT were analysed by spectral flow cytometry, simultaneously assessing 24 immune cell markers. Samples from consecutive cycles were available for a subset of 14 patients.

Conference:

Presenting Author: Büttner S

Authors: Büttner S, Detjen K, Galler M, Siefert J, Wiedenmann B,

Keywords: NET, PRRT, checkpoint inhibitors, immune response, PD1, flow cytometry,