Merck, known as MSD outside the United States and Canada, announced that Keytruda (pembrolizumab), the company’s anti-PD-1 therapy, has been approved in Japan for the treatment of certain patients with PD-L1-positive unresectable advanced/recurrent non-small cell lung cancer (NSCLC) in the first- and second-line treatment settings at a fixed dose of 200 mg every three weeks. MSD will manufacture and market Keytruda in Japan and will promote it with Taiho Pharmaceutical Co., Ltd.

“This approval in both the first- and second-line settings for advanced non-small cell lung cancer in patients whose tumours express PD-L1 marks an important milestone in Japan,” said Dr. Roger M. Perlmutter, president, Merck Research Laboratories. “Through advanced research, Merck is demonstrating its commitment to bringing meaningful therapeutic advances to people with cancer throughout the world.”

The Japanese Ministry of Health, Labour, and Welfare (MHLW) approval is supported by findings from both the KEYNOTE-024 and KEYNOTE-010 studies. KEYNOTE-024 is a randomized, open-label, phase 3 study evaluating Keytruda monotherapy at a fixed dose of 200 mg compared to standard of care platinum-containing chemotherapy for the treatment of patients with both squamous and non-squamous metastatic NSCLC. The study enrolled patients who had not received prior systemic chemotherapy treatment for their metastatic disease and whose tumors had high PD-L1 expression (as defined by a tumor proportion score [TPS] of 50 percent or more) with no EGFR or ALK aberrations. KEYNOTE-010 is an open-label, randomized, phase 2/3 trial assessing two doses of Keytruda (pembrolizumab) (2 mg/kg or 10 mg/kg every three weeks) compared to docetaxel (75 mg/m2 every three weeks), a standard of care chemotherapy. This study enrolled patients with any level of PD-L1 expression (as defined by a TPS of one per cent or more) who had progressed following platinum-containing chemotherapy and, if appropriate, targeted therapy for EGFR or ALK genomic tumour aberrations.

The PD-L1 IHC 22C3 PharmDx kit made by Dako North America, Inc., an Agilent Technologies Company, was approved in Japan on November 25 for use in detecting PD-L1, an immune-related biomarker expressed on some tumour cells. The diagnostic is intended to aid in identifying appropriate patients for treatment with Keytruda, including previously treated patients whose tumors have any level of PD-L1 expression and previously untreated patients whose tumours have high levels of PD-L1 expression. Tumours with a TPS of less than one percent are considered to have no PD-L1 expression.

Keytruda is a humanized monoclonal antibody that works by increasing the ability of the body’s immune system to help detect and fight tumour cells. Keytruda 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.

Keytruda is administered as an intravenous infusion over 30 minutes every three weeks for the approved indications. Keytruda for injection is supplied in a 100 mg single use vial.