Pivotal Phase II DESTINY-Breast01 trial meets primary endpoint

AstraZeneca and Daiichi Sankyo announce positive top-line results for pivotal Phase II DESTINY-Breast01 trial of trastuzumab deruxtecan

AstraZeneca and Daiichi Sankyo have announced positive top-line results for the pivotal Phase II DESTINY-Breast01 trial of trastuzumab deruxtecan (DS-8201).

The HER2-targeting antibody drug conjugate (ADC) and potential new medicine was evaluated in patients with HER2-positive, unresectable and/or metastatic breast cancer previously treated with trastuzumab emtansine.

The response rate in DESTINY-Breast01, as assessed by an independent review committee, confirms in a heavily-pretreated, global patient population the unprecedented clinical activity in the recently-published Phase I trial.

The safety and tolerability profile of trastuzumab deruxtecan was also consistent with previous experience. These results are expected to support planned global regulatory submissions, including a Biologics License Application with the US Food and Drug Administration (FDA) anticipated in the second half of 2019.

DESTINY-Breast01 is a pivotal Phase II, open-label, global, multicentre, two-part trial of trastuzumab deruxtecan. The optimal dose of 5.4mg/kg was previously identified in part one of the trial.

The results from part two evaluated the efficacy and safety of that dose in patients who have failed or discontinued previous treatment with trastuzumab emtansine.

Approximately one in five breast cancers are HER2-positive. Several unmet treatment needs remain today in HER2-positive metastatic breast cancer.

A recent publication in The Lancet Oncology reported long-term Phase I safety and preliminary efficacy results in HER2-positive metastatic breast cancer. This potential new medicine is currently in development for the treatment of multiple HER2-expressing cancers, including in patients with HER2-low expression.

José Baselga, Executive Vice President, R&D Oncology, said: “We believe this antibody drug conjugate has the potential to redefine the treatment of patients with HER2-expressing cancers, and we are eager to bring it as quickly as possible to patients with refractory HER2-positive breast cancer who continue to have high unmet medical need.”

Dr Antoine Yver, Executive Vice President and Global Head, Oncology Research and Development, Daiichi Sankyo, said: “These results confirm our commitment to pursue accelerated regulatory pathways in HER2-positive metastatic breast cancer with trastuzumab deruxtecan. We are more dedicated than ever to our comprehensive and ambitious development strategy evaluating the potential across a spectrum of HER2-expressing cancers including breast, gastric, lung and colorectal.”

AstraZeneca and Daiichi Sankyo plan to present the data from DESTINY-Breast01 at a forthcoming medical meeting.