TOKYO, July 10, 2019  - Astellas Pharma Inc. (TSE: 4503, President and CEO: Kenji Yasukawa, Ph.D., “Astellas” ) today announced the launch of the Smyraf® 50 mg and 100 mg  Tablets (generic name: peficitinib hydrobromide), an oral Janus kinase (JAK) inhibitor, in Japan for the treatment of rheumatoid arthritis (including prevention of structural joint damage) in patients who have an inadequate response to conventional therapies.

Smyraf®, which was discovered by Astellas, suppresses activation and proliferation of inflammatory cells involved in synovial inflammation and joint destruction in rheumatoid arthritis patients by inhibiting various inflammatory cytokine signaling pathways.

The number of rheumatoid arthritis patients in Japan is estimated to be approximately 0.6 to 1.0 million*1. Currently, disease-modifying antirheumatic drugs (DMARDs)*2 including Methotrexate (MTX) and biologics, are used to treat rheumatoid arthritis.  By providing Smyraf® as a new therapeutic option, Astellas will contribute to treatment of rheumatoid arthritis patients with an inadequate response to conventional therapy such as DMARDs.

Astellas reflected the impact from this launch in its financial forecasts of the current fiscal year ending March 31, 2020.