Research table: Pembrolizumab (Keytruda) for early breast cancer treatment

This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.

Introduction: Pembrolizumab is a checkpoint inhibitor immunotherapy drug used to treat early triple negative breast cancer at high risk of recurrence (a return of breast cancer).

Triple negative breast cancer is:

Estrogen receptor-negative (ER-negative)
Progesterone receptor-negative (PR-negative)
HER2-negative

Since pembrolizumab is given for up to one year, you get some pembrolizumab before breast surgery (called neoadjuvant therapy) and some after breast surgery.

Study findings show adding neoadjuvant pembrolizumab to neoadjuvant chemotherapy may lower the risk of breast cancer recurrence and improve overall survival in people with early triple negative breast cancer [1-2].

Learn more about pembrolizumab (including side effects) and treatment for early triple negative breast cancer.

Learn more about triple negative breast cancer.

Learn about pembrolizumab and treatment for metastatic breast cancer.

Learn about the strengths and weaknesses of different types of studies.

Study selection criteria: Randomized clinical trials with at least 500 participants with early triple negative breast cancer.

Study	Study Population (number of participants)	Follow-up (years)	Percent Surviving— Chemotherapy Plus Pembrolizumab	Percent Surviving- Chemotherapy Alone (no Pertuzumab)	Absolute Improvement in Overall Survival with the Addition of Pembrolizumab to Treatment with Chemotherapy
Randomized clinical trials
KEYNOTE-522 [2]	1,174	5	87%	82%	5%*

* Statistically significant difference between the 2 treatment groups

References

Schmid P, Cortes J, Dent R, et al. for the KEYNOTE-522 Investigators. Event-free survival with pembrolizumab in early triple-negative breast cancer. N Engl J Med. 386(6):556-567, 2022.
Schmid P, Cortes J, Dent R, et al. for the KEYNOTE-522 Investigators. Overall survival with pembrolizumab in early-stage triple-negative breast cancer. N Engl J Med. Sep 15 [Online ahead of print].

Updated 09/30/24