Trastuzumab deruxtecan in human epidermal growth factor receptor 2-positive breast cancer brain metastases: A systematic review and updated meta-analysis

Background

Trastuzumab deruxtecan (T-DXd) has shown promising activity in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) and central nervous system (CNS) involvement. In this updated meta-analysis, we explore the effectiveness of T-DXd in a large subset of patients with HER2-positive BC and CNS disease.

Methods

A systematic search was made on September 16th, 2024, for studies investigating T-DXd in the scenario of HER2-positive BC and brain metastases (BMs) and/or leptomeningeal disease (LMD). We used random effects models for all statistical analyses.

Results

We included 18 studies with 786 HER2-positive BC patients with CNS involvement (16 studies with 750 BMs patients and three studies with 36 LMD patients). We observed high overall antitumor responses (objective response rate [ORR], 60.4 %; disease control rate [DCR], 94.4 %; and clinical benefit rate [CBR], 79.3 %) and a 12-month PFS of 64.7 % and OS of 82.7 %. Intracranial ORR, DCR, and CBR were seen in 62.2 %, 88.6 %, and 68.6 % of patients, respectively, and 67.4 % achieved intracranial PFS at 12 months. Both stable and active BMs subgroups derived similar benefit from T-DXd. Better intracranial responses were seen for 33 patients with untreated BMs compared to 56 patients with previously treated or progressing lesions (odds ratio 3.82, 95 % confidence interval 1.3–10.8, p = 0.01). For the LMD group, T-DXd elicited intracranial ORR and CBR in 59.4 % and 94.1 % of patients, respectively.

Conclusions

This updated meta-analysis continues to support the overall and intracranial activity of T-DXd in patients with HER2-positive BC and CNS involvement, including those with LMD.