Daiichi Sankyo has reported positive topline results from the Phase III TROPION-Breast01 clinical trial of datopotamab deruxtecan (Dato-DXd) for the treatment of hormone receptor (HR)-positive, HER2-low or negative breast cancer.

The international, open-label, multicentre, randomised study assessed the efficacy and safety of the TROP2-directed antibody-drug conjugate (ADC) Dato-DXd against the investigator’s choice of single-agent chemotherapies including capecitabine, eribulin, gemcitabine or vinorelbine.

It included breast cancer patients who have previously progressed on or are not suitable for endocrine therapy, as per the investigator's assessment.

More than 700 patients from several sites, including Africa, Europe, South America, Asia, and North America, are enrolled on the study.

Datopotamab deruxtecan demonstrated a clinically meaningful improvement in the dual primary endpoint of overall survival (OS) and progression-free survival (PFS), as assessed by a blinded independent central review (BICR).

The company plans to further assess OS, as the data is not mature at this stage of the interim analysis.

Objective response rate, time to first subsequent therapy, disease control rate, duration of response, and investigator-assessed PFS are the study’s key secondary endpoints.

Daiichi Sankyo Research and Development global head Ken Takeshita said: “We look forward to realising the full potential of this TROP2-directed antibody-drug conjugate across breast cancer subtypes through our ongoing Phase III programme, including two trials in patients with triple-negative breast cancer.”

These two additional TROPION-Breast02 and TROPION-Breast03 studies will be carried out in collaboration with AstraZeneca.

AstraZeneca together with Daiichi Sankyo developed the specifically engineered datopotamab deruxtecan.

Daiichi Sankyo plans to submit the trial data for seeking regulatory approval.