Dr Tripathy on Real-World HER2 Testing and CDK4/6 Inhibitor Use in HER2+ Breast Cancer

Debu Tripathy, MD, professor, chairman, Department of Breast Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses real-world strategies for CDK4/6 inhibitor use and emphasizes the importance of reliable HER2 testing in HER2-positive metastatic breast cancer.

Ensuring reliable HER2 testing and seeking guidance from pathologists when needed are crucial steps in breast cancer management, Tripathy begins. Additionally, understanding the differentiation between patients who qualify for de-escalated therapy at stage I and those requiring more intensive treatment is vital, he says. Cardiac monitoring plays a key role in choosing breast cancer therapies, and transparent communication with patients about treatment decisions is essential to alleviate their anxieties amidst the testing process, Tripathy explains.

During the 41st Annual Miami Breast Cancer Conference, Tripathy highlighted various aspects of CDK4/6 inhibitor use beyond randomized trials. Although randomized trials are considered the gold standard for comparing treatment efficacy, they have limitations, he elucidates. Clinical trial eligibility often favors patients with good performance statuses, excludes those with comorbidities, and may lack the diversity representative of the general population, Tripathy states, saying that real-world data sourced from electronic medical records, insurance data, and de-identified claims, offer a more comprehensive view of treatment outcomes across diverse patient populations.

For instance, real-world data from the Flatiron database, which collates payment and reimbursement information, provided critical insights into the safety and efficacy of palbociclib (Ibrance) and supported the FDA approval of this agent in combination with endocrine therapy for male patients with hormone receptor–positive, HER2-negative breast cancer. This real-world evidence enhanced the field’s understanding of how CDK4/6 inhibitors act in male patients and underscored the importance of complementing clinical trial data with broader, population-based insights, Tripathy emphasizes.

The integration of HER2 testing protocols, thoughtful patient stratification, and continuous cardiac surveillance, as well as the leveraging of real-world data to extend treatment knowledge, are imperative for optimizing breast cancer care, he explains. This emphasizes the invaluable role of real-world evidence in refining treatment strategies and addressing the diversity of patient needs beyond the controlled environment of clinical trials, Tripathy concludes.