KENILWORTH - Merck (NYSE: MRK), known as MSD outside the United States and Canada, announced today that the European Commission has approved KEYTRUDA, Merck's anti-PD-1 therapy, as a monotherapy for the first-line treatment of adult patients with metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) colorectal cancer.

This approval is based on results from the pivotal Phase 3 KEYNOTE-177 trial, in which KEYTRUDA monotherapy significantly reduced the risk of disease progression or death by 40% (HR=0.60 [95% CI, 0.45-0.80]; p=0.0002) compared with chemotherapy (investigator's choice: mFOLFOX6 [oxaliplatin, leucovorin and fluorouracil (FU)] with or without bevacizumab or cetuximab; or FOLFIRI [irinotecan, leucovorin and FU] with or without bevacizumab or cetuximab). In the trial, treatment with KEYTRUDA also more than doubled median progression-free survival (PFS) compared with chemotherapy (16.5 months [95% CI, 5.4-32.4] versus 8.2 months [95% CI, 6.1-10.2]). There was a lower incidence of Grade 3 treatment-related adverse events (TRAEs) with KEYTRUDA compared with chemotherapy (22% versus 66%), and no new toxicities were observed. This approval marks the first gastrointestinal indication for KEYTRUDA in Europe and makes KEYTRUDA the first anti-PD-1/L1 therapy approved in Europe for these patients.

'Before the KEYNOTE-177 trial, conventional chemotherapy with targeted therapy was the standard of care for patients with metastatic colorectal cancer who have tumors that are MSI-H/dMMR,' said Dr. Thierry Andre, professor of medical oncology at Sorbonne University and head of the medical oncology department at St. Antoine Hospital, Assistance Publique Hopitaux de Paris. 'With this approval, patients with metastatic colorectal cancer that is MSI-H or dMMR status will gain a monotherapy treatment option that has shown superior progression-free survival compared to standard of care chemotherapy.'

'This decision by the European Commission, which was based on the important findings from KEYNOTE-177, exemplifies our commitment to using biomarkers such as MSI/MMR to help identify patients who are most likely to respond to KEYTRUDA,' said Dr. Scot Ebbinghaus, vice president, clinical research, Merck Research Laboratories. 'Our efforts in biomarker-driven research across tumor types - including colorectal cancer, the most common type of gastrointestinal cancer - will continue to help us bring new options to patients across the globe.'

This approval allows marketing of KEYTRUDA monotherapy in all 27 European Union (EU) member states plus Iceland, Lichtenstein, Norway and Northern Ireland. Following Brexit, in line with the reliance route, this approval is also valid in Great Britain.

Data Supporting the European Approval

The approval was based on data from KEYNOTE-177, a multi-center, randomized, open-label, active-controlled trial that enrolled 307 patients with previously untreated metastatic MSI-H or dMMR colorectal cancer. Microsatellite instability (MSI) or mismatch repair (MMR) tumor status was determined locally using polymerase chain reaction or immunohistochemistry, respectively. Patients with autoimmune disease or a medical condition that required immunosuppression were ineligible.

Patients were randomized 1:1 to receive KEYTRUDA (200 mg intravenously) every three weeks or investigator's choice of the following chemotherapy regimens given intravenously every two weeks: mFOLFOX6 (oxaliplatin, leucovorin and FU) or mFOLFOX6 in combination with either bevacizumab or cetuximab: oxaliplatin 85 mg/m2, leucovorin 400 mg/m2 (or levoleucovorin 200 mg/m2), and FU 400 mg/m2 bolus on Day 1, then FU 2,400 mg/m2 over 46-48 hours; plus bevacizumab 5 mg/kg on Day 1 or cetuximab 400 mg/m2 on first infusion, then 250 mg/m2 weekly

FOLFIRI (irinotecan, leucovorin, and FU) or FOLFIRI in combination with either bevacizumab or cetuximab: irinotecan 180 mg/m2, leucovorin 400 mg/m2 (or levoleucovorin 200 mg/m2), and FU 400 mg/m2 bolus on Day 1, then FU 2,400 mg/m2 over 46-48 hours; plus bevacizumab 5 mg/kg on Day 1 or cetuximab 400 mg/m2 on first infusion, then 250 mg/m2 weekly

Treatment with KEYTRUDA or chemotherapy continued until Response Evaluation Criteria in Solid Tumors (RECIST) v1.1-defined progression of disease as determined by the investigator or unacceptable toxicity. Patients treated with KEYTRUDA without disease progression could be treated for up to 24 months. Assessment of tumor status was performed every nine weeks. Patients randomized to chemotherapy were offered KEYTRUDA at the time of disease progression. The main efficacy outcome measure was PFS as assessed by blinded independent central review (BICR) according to RECIST v1.1, modified to follow a maximum of 10 target lesions and a maximum of five target lesions per organ, and overall survival (OS). Additional efficacy outcome measures were objective response rate (ORR) and duration of response (DOR).

In this trial, KEYTRUDA monotherapy significantly reduced the risk of disease progression or death from any cause by 40% (HR=0.60 [95% CI, 0.45-0.80]; p=0.0002) and showed a median PFS of 16.5 months (95% CI, 5.4-32.4) compared with 8.2 months (95% CI, 6.1-10.2) for patients treated with chemotherapy. For PFS, in the KEYTRUDA arm, there were 82 patients (54%) with an event versus 113 patients (73%) in the chemotherapy arm. Overall survival analysis is ongoing. For patients treated with KEYTRUDA, the ORR was 44% (95% CI, 35.8-52.0), with a complete response rate of 11% and a partial response rate of 33%. For patients treated with chemotherapy, the ORR was 33% (95% CI, 25.8-41.1), with a complete response rate of 4% and a partial response rate of 29%. Median DOR was not reached (range, 2.3+ to 41.4+) with KEYTRUDA versus 10.6 months (range, 2.8 to 37.5+) with chemotherapy. Based on 67 patients with a response in the KEYTRUDA arm and 51 patients with a response in the chemotherapy arm, 85% in the KEYTRUDA arm had a duration of response greater than or equal to 12 months versus 44% in the chemotherapy arm.

Among the 153 patients with MSI-H or dMMR colorectal cancer treated with KEYTRUDA, the median duration of exposure to KEYTRUDA was 11.1 months (range, 1 day to 30.6 months). Adverse reactions occurring in patients with MSI-H or dMMR colorectal cancer were similar to those occurring in 2,799 patients with melanoma or non-small cell lung cancer treated with KEYTRUDA as a single agent.

About Microsatellite Instability-High

Microsatellite instability (or MSI) is defined by the National Cancer Institute as a change that occurs in the DNA of certain cells, such as tumor cells, in which the number of microsatellite repeats (short, repeated sequences of DNA) is different from the number of repeats that was in the DNA when it was inherited. The cause of MSI may be a defect in the ability to repair mistakes made when DNA is copied in the cell. This defect is also referred to as mismatch repair deficiency (dMMR).

About Colorectal Cancer in Europe

Colorectal cancer starts in the colon or the rectum, and these cancers are referred to as colon cancer or rectal cancer depending on where the cancer starts. Colorectal cancer often begins with growths on the inner lining of the colon or rectum called polyps, which can change into cancer over time. Colorectal cancer is the third most commonly diagnosed cancer and the second most common cause of cancer-related death worldwide. Worldwide, it is estimated there were more than 1,930,000 new cases of colorectal cancer in 2020. In Europe, it is estimated there were nearly 520,000 new cases of colorectal cancer. It is estimated approximately 4-20% of colorectal cancer patients (inclusive of all stages of disease) have tumors that score as either MSI-H or dMMR when testing is performed.

About KEYTRUDA (pembrolizumab) Injection, 100 mg

KEYTRUDA is an anti-PD-1 therapy that works by increasing the ability of the body's immune system to help detect and fight tumor cells. 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 tumor cells and healthy cells.

Merck has the industry's largest immuno-oncology clinical research program. There are currently more than 1,300 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.

About Merck

For 130 years, Merck, known as MSD outside of the United States and Canada, has been inventing for life, bringing forward medicines and vaccines for many of the world's most challenging diseases in pursuit of our mission to save and improve lives. We demonstrate our commitment to patients and population health by increasing access to health care through far-reaching policies, programs and partnerships. Today, Merck continues to be at the forefront of research to prevent and treat diseases that threaten people and animals including cancer, infectious diseases such as HIV and Ebola, and emerging animal diseases as we aspire to be the premier research-intensive biopharmaceutical company in the world.

Forward-Looking Statement of Merck & Co., Inc., Kenilworth, N.J., USA

This news release of Merck & Co., Inc., Kenilworth, N.J., USA (the 'company') includes 'forward-looking statements' within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company's management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of the global outbreak of novel coronavirus disease (COVID-19); the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the company's ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the company's patents and other protections for innovative products and the exposure to litigation, including patent litigation, and/or regulatory actions.

The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the company's 2019 Annual Report on Form 10-K and the company's other filings with the Securities and Exchange Commission (SEC) available at the SEC's Internet site (www.sec.gov).

Contact:

Patrick Ryan

Tel: (201) 452-2409

(C) 2021 Electronic News Publishing, source ENP Newswire