Pembrolizumab monotherapy for previously treated metastatic HER2-negative breast cancer with germline <i>APOBEC3B</i> deletion: results of the phase II AUROR study.

ABSTRACT:

Background

A common germline deletion polymorphism in the APOBEC3B gene increases the rate of somatic hypermutation in breast cancer, which in turn is associated with greater neoantigen burden and immune activation. This phase II study evaluated the impact of the APOBEC3B deletion polymorphism on the response to pembrolizumab monotherapy in metastatic HER2-negative breast cancer patients.

Methods

Eligible patients had a confirmed diagnosis of metastatic HER2-negative breast cancer, 1-3 prior lines of therapy, and documented homozygous or heterozygous germline deletion of APOBEC3B. Patients received 200 mg of pembrolizumab intravenously every 3 weeks for up to 2 years. The primary endpoint was objective response rate. Secondary endpoints were disease cont

SUBMITTER: Ho GF 

PROVIDER: S-EPMC12281068 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature