The KEYNOTE-522 trial met its two primary endpoints of complete pathologic response and event-free survival, showing statistically significant and clinically significant improvement in SES compared to neoadjuvant chemotherapy alone.
A pivotal study of pembrolizumab (Keytruda, Merck) in combination with chemotherapy showed statistically significant improvements in event-free survival (ESS) in patients with high-risk and stage-stage triple-negative breast cancer (TNBC). early, according to a Liberation press.
The KEYNOTE-522 trial enrolled 1174 patients who were randomized to one of 2 treatment regimens. The investigator arm received pembrolizumab plus paclitaxel and carboplatin for 4 cycles. This was followed by pembrolizumab plus cyclophosphamide and doxorubicin or epirubicin for 4 cycles of neoadjuvant therapy, before receiving 9 cycles of pembrolizumab as adjuvant therapy after surgery. The control group received a placebo instead of pembrolizumab during these cycles.
TNBC is an aggressive form of breast cancer that has a high rate of recurrence within the first 5 years after diagnosis, according to the press release. Although some breast cancers may test positive for estrogen receptors, progesterone receptors, or human epidermal growth factor receptor 2 overexpression, the TNBC test is negative for all 3. About 15% to 20% of all breast cancers are TNBC, and it tends to be more common in women under the age of 40, who are African American or who have a BRCA1 mutation.
Pembrolizumab works by increasing the ability of the body’s immune system to help detect and fight tumor cells, according to the press release. The KEYNOTE-522 trial met its dual primary endpoint of EFS and showed statistically significant and clinically significant improvement over neoadjuvant chemotherapy alone.
“Keytruda is the first immunotherapy to show positive results for event-free survival in patients with early-stage TNBC at high risk, a particularly aggressive form of breast cancer,” said Roy Baynes, MMed, PhD, FCP , senior vice president, head of global clinical development and chief medical officer of Merck Research Laboratories, in a press release. “The improvement in pathologic complete response rates initially seen after preoperative treatment was encouraging, and now that we see the data maturing after 4 years to include statistically significant improvement in event-free survival, we look forward to working with the FDA. and other global authorities to bring this new option to patients as quickly as possible. “
Previous analysis of the complete pathological response of KEYNOTE-522 also showed a statistically significant increase in patients with early stage TNBC, regardless of PD-L1 status. This was the other double primary endpoint of the trial, as announced in 2019. In addition, the researchers found a safety profile consistent with that seen in other studies and did not identify any new signals of security.
Merck Announces Phase 3 KEYNOTE-522 Trial Achieves Double Primary Endpoint of Event-Free Survival (ESS) in Patients With High-Risk Early-Stage Triple-Negative Breast Cancer (TNBC) [news release]. Merck; May 13, 2021. https://www.merck.com/news/merck-announces-phase-3-keynote-522-trial-met-dual-primary-endpoint-of-event-free-survival-efs-in-patients-with- triple-negative-early-stage-high-risk-tnbc-breast cancer /. Accessed May 13, 2021.