Enhertu (fam-trastuzumab deruxtecan-nxki)

P2, N=39, Recruiting, Peking Union Medical College | Trial primary completion date: Jul 2026 --> Jul 2028

USP9X inhibition enhances the lysosomal targeting of HER2, thereby potentiating ADC payload release and reducing tumor recurrence after T-DXd treatment. Our results elucidate the functional relevance of HER2 heterogeneity and propose improved therapies for these tumors.

P2, N=1, Active, not recruiting, Brown University | Trial completion date: Jan 2026 --> May 2026

P1/2, N=159, Not yet recruiting, Centro Di Riferimento Oncologico Di Aviano

A retrospective analysis was conducted on 104 patients diagnosed with advanced breast cancer who received trastuzumab deruxtecan treatment at the Affiliated Hospital of Xuzhou Medical University, with the study period spanning from January 2023 to September 2025. Earlier initiation of trastuzumab deruxtecan may maximize survival benefits. These findings help bridge the gap between clinical trial evidence and routine clinical practice.

P2, N=150, Not yet recruiting, Jiangsu HengRui Medicine Co., Ltd.

P2, N=477, Active, not recruiting, AstraZeneca | Recruiting --> Active, not recruiting

Trastuzumab deruxtecan demonstrates substantial antitumor activity through potent cytotoxic effects and a bystander effect, supporting its efficacy in tumors with intratumoral heterogeneity or downstream pathway activation. In contrast, tucatinib-based regimens represent an important option for patients with brain metastases and tumors expressing p95HER2. The ongoing development of novel antibody-drug conjugates and bispecific antibodies is expected to further advance personalized sequential therapy targeting composite resistance mechanisms.

Although no high-penetrance genetic variants were identified, candidate-based genetic analyses suggested that host genetic factors may contribute to ILD susceptibility. Integrating genetic information with clinical assessment may help refine the risk stratification for T-DXd-induced ILD in future studies.

Preclinical studies have demonstrated synergistic antitumor activity when CDK4/6 inhibitors are combined with trastuzumab, pertuzumab, or newer HER2-targeted agents across multiple HER2+ breast cancer models. In the metastatic setting, phase II trials including MonarcHER and PATRICIA II have shown encouraging efficacy signals, while the phase III PATINA trial demonstrated a clinically meaningful 15.2-month progression-free survival benefit with palbociclib plus anti-HER2 therapy and endocrine therapy...Despite these advances, key challenges remain including the identification of predictive biomarkers, optimal treatment sequencing, and the integration of emerging HER2-targeted agents such as trastuzumab deruxtecan. Novel CDK4/6 inhibitors including dalpiciclib and next-generation agents are expanding therapeutic options, while combination strategies incorporating CDK7 inhibition represent future therapeutic frontiers. The evolving landscape of HER2+/HR+ breast cancer treatment increasingly emphasizes precision medicine approaches that leverage cell cycle control mechanisms to overcome resistance and improve patient outcomes across all disease stages.