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Using RWD to help validate generalizability of RCT results


March 2021


DeMichele, A., Cristofanilli, M., Brufsky, A. et al. Comparative effectiveness of first-line palbociclib plus letrozole versus letrozole alone for HR+/HER2− metastatic breast cancer in US real-world clinical practice. Breast Cancer Res 23, 37 (2021).

Our summary

Real-world data can provide clinical practice insights on the safety and efficacy of new drug treatments studied in clinical trials, expanding the generalizability of clinical trial findings. To gain a better understanding of the role of palbociclib in patients with metastatic breast cancer in the real-world, this study examined the effectiveness of first-line palbociclib plus letrozole versus letrozole alone on survival outcomes in patients with hormone receptor–positive (HR+)/human epidermal growth factor receptor–negative (HER2−) metastatic breast cancer treated in routine clinical practice in the US.

Results showed longer real-world progression-free survival and overall survival with this real world population of patients with HR+/HER2- metastatic breast cancer receiving first-line palbociclib plus letrozole than letrozole alone.

Why this matters

One of the most touted general applications of RWD is as an external validator of the generalizability of results obtained within the boundaries of regimented clinical trials. This study offers a prime example of such an application. Palbociclib ushered the era of CDK inhibitors in breast cancer. Considering the impact of this therapeutic class, it is reassuring to see that the effectiveness in routine care across populations far more sprawling and diverse than in clinical trials mirrors the results obtained in pivotal clinical trials. Furthermore, it is a demonstration of the value of RWD in building evidence-based care that makes a true difference for patients at large.

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