Benzinga | Nov 23, 2021 11:04AM EST

Merck Says Health Canada Approves KEYTRUDA In Combination With Chemotherapy For Treatment Of Locally Recurrent Unresectable Or Metastatic Triple-Negative Breast Cancer

Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced that Health Canada has granted conditional approval for KEYTRUDA(r) (pembrolizumab), Merck's anti-PD-1 therapy, in combination with chemotherapy for the treatment of locally recurrent unresectable or metastatic triple-negative breast cancer (TNBC) in adults whose tumors express PD-L1 (Combined Positive Score [CPS] ?10) and who have not received prior chemotherapy for metastatic disease.1 This conditional approval is based on the results of the pivotal Phase 3 KEYNOTE-355 trial which demonstrated KEYTRUDA(r)'s ability to improve progression-free survival (PFS) in combination with chemotherapy (nab-paclitaxel, paclitaxel or gemcitabine/carboplatin), as compared to chemotherapy alone.2

"As a complex and challenging subtype of cancer to treat, this approval is a welcome development for Canadian patients with triple-negative breast cancer," said Dr. David Cescon, Clinician Scientist, Princess Margaret Cancer Centre. "About 10-20% of breast cancers are triple-negative breast cancers. Historically, chemotherapy has been the main treatment for this type of breast cancer, and there has been great interest in finding other therapies to help improve patient outcomes. This news means that there will be more options available and thus represents an important advance in the treatment of triple negative-breast cancer."

Breast cancer is one of the most common cancers among Canadian women and the second leading cause of death from cancer in Canadian women.3 In 2021, over 27,000 Canadians were estimated to be diagnosed.3 TNBC is an aggressive subtype of breast cancer which lacks estrogen receptors, progesterone receptors and HER2 amplification, making it difficult to target therapeutically.4 While TNBC can have the same signs and symptoms as other common types of breast cancer,5 it differs from other types of invasive breast cancer in that it grows and spreads quickly, is more likely to have spread at the time it's found and has fewer treatment options compared to other types of invasive breast cancer. 6

"When we hear from people in the metastatic breast cancer community, they say they want more tools in the toolbox -- more options to help them treat their disease. And while there have been some advances in targeted treatment in breast cancer, fewer of them have been intended for people with the triple-negative diagnosis," said MJ DeCoteau, Founder and Executive Director, Rethink Breast Cancer. "New treatment options have been anticipated by patients and physicians alike for some time."

"It can be devastating to receive a triple-negative breast cancer diagnosis," said Cathy Ammendolea, Chair of the Board, Canadian Breast Cancer Network. "It can be worrying for patients to learn about the aggressive nature of the disease and the limited treatment options available to them, but this news can bring some hope to patients and their families who are on this journey."