Eisai Co. and nippon medac Co., a subsidiary of medac group, have launched the anti-rheumatic agent 'Metoject Subcutaneous Injection 7.5mg Pen 0.15mL, 10mg Pen 0.20mL, 12.5mg Pen 0.25mL and 15mg Pen 0.30mL' (methotrexate, or MTX), in Japan.

The product received manufacturing and marketing approval in Japan on February 15, 2024, and has been published in Japan’s National Health Insurance Drug Price List. Based on the license agreement signed by Eisai and medac GmbH in May 2019, nippon medac will hold the marketing authorisation of Metoject, while Eisai will be responsible for product distribution of Metoject in Japan.

It is estimated that there are approximately 700,000 - 800,000 rheumatoid arthritis patients in Japan, and MTX is used as the first-line option for the treatment of rheumatic arthritis. Metoject Subcutaneous Injection Pen will be the first self-administrable MTX subcutaneous injection pen-type autoinjector for rheumatoid arthritis in Japan and was developed to reduce the burden on patients and improve safety during self- injection. 

For rheumatoid arthritis, it is believed that MTX regulates cell growth by inhibiting folate metabolism in lymphocytes and other cells, and also has an anti-inflammatory mechanism through the promotion of adenosine synthesis in vascular endothelial cells and other cells in synovial membranes.