Study of Pembrolizumab in Metastatic HER2-negative Breast Cancer Patients With APOBEC3B Mutation

Summary

This is an open label investigator initiated Phase II study of single agent pembrolizumab (Keytruda) in metastatic HER2-receptive negative breast cancer patients with germline deletion in the cytosine deaminase (APOBEC3B) gene. Approximately 44 subjects from Malaysia and Singapore will be enrolled in this study to examine the efficacy of pembrolizumab when given 200 mg intravenously (IV) every 3 weeks (Q3W) for up to 35 administrations (2 years). This study will be conducted in conformance with Good Clinical Practices. Specific procedures to be performed during the trial, as well as their prescribed times and associated visit windows, are outlined in the Trial Flow Chart.

Timeline

Start

2020-07-03

Primary completion

2025-12-01

Completion

2026-12-01

Publications

• Ho GF, Lee SC, Bustam AZ, Alip A, Abdul Satar NF, Saad M, Malik RA, Lim SE, Ow SGW, Wong A, Chong WQ, Ang YLE, Lee AWY, Hasan SN, Tuan Zaid N, Law KB, Toh YY, Tan HC, Selvam B, Lim J, Pan JW, Teo SH. Pembrolizumab monotherapy for previously treated metastatic HER2-negative breast cancer with germline APOBEC3B deletion: results of the phase II AUROR study. Lancet Reg Health West Pac. 2025 Jul 13;60:101637. doi: 10.1016/j.lanwpc.2025.101637. eCollection 2025 Jul.

Drugs

Indications