4 January 2019 - - Keytruda, US-based pharmaceutical company Merck's (NYSE: MRK) anti-PD-1 therapy, has simultaneously received five new approvals from the Japan Pharmaceuticals and Medical Devices Agency, including three expanded uses in advanced non-small lung cancer (NSCLC), one in melanoma, as well as a new indication in advanced microsatellite instability-high (MSI-H) tumors, the company said.

The new approvals were all granted priority review by the PMDA include Keytruda in combination with pemetrexed and platinum-based chemotherapy (cisplatin or carboplatin) for the first-line treatment of unresectable, advanced/recurrent nonsquamous NSCLC regardless of PD-L1 expression (based on results of the Phase 3 trial KEYNOTE-189).

Also, Keytruda in combination with carboplatin and paclitaxel or nab-paclitaxel for the first-line treatment of unresectable, advanced/recurrent squamous NSCLC regardless of PD-L1 expression (based on results of the Phase 3 trial KEYNOTE-407).

The new approvals include Keytruda monotherapy in the first-line treatment of PD-L1-positive (Tumor Proportion Score [TPS] ≥1%) unresectable, advanced/recurrent NSCLC (based on results of the Phase 3 trial KEYNOTE-042).

Also, Keytruda monotherapy as adjuvant therapy for melanoma (based on results of the Phase 3 trial EORTC1325/KEYNOTE-054, a study sponsored by Merck and conducted in collaboration with the European Organisation for Research and Treatment of Cancer [EORTC]).

Finally, the new approvals include Keytruda monotherapy for the treatment of advanced/recurrent MSI-H solid tumors that have progressed after chemotherapy (only if refractory or intolerant to standard therapies), based on results of two Phase 2 trials, KEYNOTE-164 and KEYNOTE-158.

A companion diagnostic to detect MSI-H, the MSI test kit FALCO by FALCO Biosystems Ltd., has also been approved.

In addition to the adjuvant therapy approval, dosage and administration for all patients with melanoma has been changed from intravenous infusion of 2 mg/kg (body weight) over 30 minutes at a three-week interval to intravenous infusion of the fixed dose of 200 mg over 30 minutes at a three-week interval.

Previously, Keytruda was approved in Japan for the treatment of curatively unresectable melanoma; PD-L1-positive unresectable, advanced or recurrent NSCLC (TPS≥1% in second-line setting; TPS≥50% in first-line setting); relapsed or refractory classical Hodgkin lymphoma; and curatively unresectable urothelial carcinoma that progressed after chemotherapy.

Keytruda is marketed by MSD in Japan and is co-promoted with Taiho Pharmaceutical Co., Ltd.

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 humanised 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.