AstraZeneca gains on positive late-stage data for breast cancer therapy
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AstraZeneca (NASDAQ:AZN) shares outperformed the broader market in London on Monday in reaction to positive late-stage data for Enhertu in a group of breast cancer patients with low levels of a protein called HER2.
The Anglo-Swedish drugmaker has partnered with Daiichi Sankyo (OTCPK:DSKYF)
(OTCPK:DSNKY) to design Enhertu as an antibody-drug conjugate (ADC) targeted at HER2, a tyrosine kinase receptor expressed on multiple types of cancer.
The DESTINY-Breast04 trial was designed to evaluate Enhertu versus physicianâs choice of chemotherapy in patients HER2 low unresectable and/or metastatic breast cancer who had received one or two prior lines of chemotherapy. In terms of hormone receptor (HR) status, 480 patients were HR-positive (n=480), while 60 of them were HR negative.
According to data from the pivotal study, Enhertu, also called trastuzumab deruxtecan, showed a statistically significant and clinically meaningful improvement in both progression-free survival (PFS) and overall survival (OS) regardless of HR status.
The trial met the primary endpoint indicating a better PFS in previously-treated patients with HR-positive, HER2 low metastatic breast cancer compared to the standard of care chemotherapy.
The study also met the secondary endpoint of PFS in those with HER2 low metastatic breast cancer regardless of HR status. It also met other key secondary endpoints of OS in those with HR-positive disease and in patients regardless of their HR status.
The safety profile of Enhertu was consistent with previous trial findings for the drug, and the study did not indicate any new safety concerns for the experimental therapy.
The companies plan to present findings at a future medical event, and expect to submit data for global regulatory agencies âwith the goal of potentially bringing ENHERTU to patients with metastatic breast cancer previously considered to be HER2 negative,â Ken Takeshita, Global Head of R&D, for Japanese drugmaker Daiichi Sankyo said.
 "HER2 low is a large and previously unaddressed patient pool in breast cancer," Reuters reported quoting Credit Suisse after the data readout. The analysts project a 50% chance of a $3B peak sales opportunity for the drug in the new patient group.
Enhertu is licensed in the U.S. as a third-line option for HER2-positive breast cancer in a metastatic setting.
Citing an outsize contribution of collaboration revenue, AstraZeneca (AZN) reported $214M total revenue for the treatment in 2021, indciating~123% YoY growth.