Iterative and prolonged remission in metastatic breast cancer using pegylated irinotecan: a case report

INTRODUCTION: Pegylated irinotecan NKTR-102 is a topoisomerase I inhibitor-polymer conjugate. This new formulation of irinotecan has been evaluated in a phase II clinical trial and is showing remarkable activity. To the best of our knowledge, this is the first case report of an impressive iterative response to pegylated irinotecan NKTR-102 in metastatic breast cancer. CASE PRESENTATION: We report the case of a 49-year-old Caucasian woman diagnosed with metastatic luminal A breast cancer with initial bone followed by liver and bone marrow metastases, treated with three lines of hormonal therapy, targeted therapy and six lines of chemotherapy. She showed no major response to conventional treatment, whereas, the tumor shrinkage under pegylated irinotecan NKTR-102 was impressive, durable and iterative. CONCLUSIONS: Reintroduction of an active drug is a valid approach as illustrated by our case. The results of the current phase III trials of pegylated irinotecan NKTR-102 are eagerly awaited.