Pilot study evaluates antitumor effects of trastuzumab deruxtecan in patients with varying HER2 expressions, indicating broad therapeutic potential.
Key Points
To determine pharmacodynamic responses and antitumor efficacy of trastuzumab deruxtecan in patients with advanced solid tumors and varying HER2 expression levels.
Multicenter pilot study with patients possessing advanced solid tumors and HER2 expression levels of 1+ or higher.
Patients received T-DXd (5.4 mg/kg intravenously every 3 weeks) along with tumor and blood samples for biomarker analysis.
Baseline HER2 expression was measured using immunohistochemistry across various patients.
Of 61 patients treated, 1 achieved a complete response and 14 showed confirmed partial responses despite differing HER2 status.
15 of 21 biopsies indicated topoisomerase 1 target modulation, with 14 showing DNA damage repair induction.
Significant tumor infiltration and activation of CD8+ T cells were noted, correlating with patient responses.