Merck announced that Health Canada has granted approval for KEYTRUDA®, Merck's anti-PD-1 therapy, as a treatment for adult patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment and then continued as monotherapy as adjuvant treatment after surgery. This approval is based on the results from the Phase 3 KEYNOTE-522 trial, which demonstrated a statistically significant improvement in event-free survival (EFS) and pathological complete response (pCR) rate among patients. In 2021, over 28,000 Canadians were estimated to be diagnosed with breast cancer, one of the most common cancers among Canadian women, TNBC is an aggressive subtype of breast cancer that tends to grow and spread quickly. TNBC is also characterized by its high recurrence rate within the first five years after diagnosis.3 Many breast cancers have receptors for common therapeutic targets such as estrogen, progesterone, or HER2 whereas triple-negative breast cancer tests negative for all three, making this type of cancer difficult to treat as it has fewer treatment options.

KEYNOTE-522 Trial: Health Canada's approval is based on findings from KEYNOTE-522, a Phase 3 randomized, double-blind clinical trial that enrolled 1,174 patients. The eligibility criteria for this study were newly diagnosed previously untreated high-risk early-stage TNBC (tumor size >1 cm but =2 cm in diameter with nodal involvement or tumor size >2 cm in diameter regardless of nodal involvement), regardless of tumor PD-L1 expression. The major efficacy outcome measures were pathological complete response (pCR) rate and event-free survival (EFS). pCR was defined as the absence of invasive cancer in the breast and lymph nodes and was assessed by the blinded local pathologist at the time of definitive surgery.

EFS was defined as the time from randomization to the first occurrence of any of the following events: progression of disease that precludes definitive surgery, local or distant recurrence, second primary malignancy, or death due to any cause.1 The results of KEYNOTE-522 demonstrated a statistically significant improvement in pCR and EFS for patients randomized to receive KEYTRUDA® in combination with chemotherapy followed by adjuvant KEYTRUDA® as monotherapy compared with patients randomized to placebo in combination with chemotherapy followed by placebo alone.Triple-Negative Breast Cancer: TNBC is an aggressive subtype of breast cancer that lacks estrogen receptors, progesterone receptors, and HER2 amplification, making it difficult to target therapeutically. TNBC has the highest rates of metastatic disease and the poorest overall survival of all breast cancer subtypes. It characteristically has a high recurrence rate within the first five years after diagnosis and tends to be more common in women under the age of 40. KEYTRUDA: KEYTRUDA® is an anti-PD-1 therapy that works by helping increase the ability of the body's immune system to help detect and fight tumour cells.1 KEYTRUDA® is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumour cells and healthy cells.1 KEYTRUDA® was first approved in Canada in 2015 and currently has indications in several disease areas, including advanced renal cell carcinoma, bladder cancer, non-small cell lung carcinoma, primary mediastinal B-cell lymphoma, classical Hodgkin lymphoma, colorectal cancer, endometrial carcinoma, esophageal cancer, triple-negative breast cancer, melanoma, and head and neck squamous cell carcinoma.1Our Focus on Cancer: The company's goal is to translate progressive science into innovative oncology medicines to help people with cancer worldwide.

At Merck Canada, helping people fight cancer is passion and supporting accessibility to cancer medicines is the company's commitment. The company's focus is on pursuing research in oncology and accelerating every step in the journey — from lab to clinic — to potentially bring new hope to people with cancer.