Roche gets CE Mark for companion diagnostic to identify patients with HER2-low metastatic breast cancer eligible for Enhertu

HER2 is a receptor protein that helps cancer cells grow quickly. To determine a patient's HER2 status, pathologists evaluate, or score, the level of HER2 protein expressed in breast cancer tissue samples. If a patient's tumour expresses high levels of HER2, the patient is identified as HER2-positive and may be considered for HER2-targeted treatment. However, half of all patients with metastatic breast cancer express low levels of HER2 which historically classified them as HER2-negative.

"We are proud to continue our innovation in breast cancer diagnostics through critical tests like this one, which helps identify patients with HER2-low status," said Jill German, Head of Pathology Lab at Roche Diagnostics. "With this expanded approval of our test, we're pleased that more metastatic breast cancer patients across the world may be correctly identified and potentially eligible for this targeted therapy."

The VENTANA HER2 (4B5) test now includes a scoring algorithm that helps pathologists to identify "low expressors" of HER2, assigning a HER2 low status to this group of patients. With this lower cutoff, the test is able to identify patients who may benefit from ENHERTU as a treatment option.

Breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases diagnosed worldwide each year. More than 685,000 people die from breast cancer every year.

The CE Mark of the new HER2-low indication expands on the intended use for Roche's proven, on-market VENTANA HER2 (4B5) test, delivering timely, clear and confident results. "The launch exemplifies Roche's commitment to continuing to innovate integrated, high medical value solutions that help to advance personalised healthcare," the release stated.

Roche's pre-diluted VENTANA HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx, used in combination with the fully automated BenchMark IHC/ISH slide staining instrument, standardises all immunohistochemistry (IHC) processes from baking through staining, and reduces the possibility of human error. It also minimises inherent variability resulting from individual reagent dilution and other processes found in manual and semi-automated IHC methods. The Roche HER2 (4B5) clone achieves consistently high proficiency assessment scores compared to other clones and demonstrates high concordance with HER2 FISH, empowering laboratories to employ the most widely adopted and reliable HER2-IHC primary antibody.

The VENTANA HER2 (4B5) test was used as part of the DESTINY-Breast04 trial to identify patients whose tumours expressed low levels of HER2 protein (IHC 1+ or IHC 2+/ISH-). The trial reported a 50% reduction in the risk of disease progression or death and an overall survival gain of six months over standard of care in patients treated with ENHERTU whose tumours had low levels of HER2 expression, leading to the approval of ENHERTU in this patient population.