Kissei Pharmaceutical Co., Ltd. announced that TAVALISSE ® Tab. 100mg and 150mg, for chronic idiopathic thrombocytopenic purpura (ITP) launched on April 6, 2023, in Japan. TAVALISSE® is an oral spleen tyrosine kinase (SYK) inhibitor discovered by Rigel Pharmaceuticals Inc. It suppresses platelet destruction by macrophages thereby preventing platelet depletion and potentially improving the bleeding symptoms caused by chronic ITP.

TAVALISSE® has a different mechanism of action than existing treatments. Therefore, it represents a new treatment option for adult patients with chronic ITP who have had an insufficient response to or were unable to tolerate conventional treatments such as steroids. Kissei submitted a marketing authorization application in Japan for the indication of chronic ITP in April 2022, based on the successful results of Phase 3 clinical trials in patients in Japan and the United States, and received approval in December 2022.

TAVALISSE® was listed on the NHI drug price list on March 15, 2023. The product has been approved in the United States since 2018, under the brand name of TAVALISSE ® (fostamatinib disodium hexahydrate) tablets and is indicated for the treatment of adult patients with chronic ITP who have had an insufficient response to a previous treatment. Product approvals have followed in Europe, Israel and Canada.

It has been granted orphan drug designation in the United States, Japan and So uth Korea. In order to use this drug appropriately, it is important to accumulate information on the patient's background under actual use, as well as information on safety and efficacy. Kissei will conduct all-case surveillance in all patients who are administered the agent until a pre- determined number of patients has been reached and promote the proper use of this drug with an approval condition imposed by the Ministry of Health, Labour and Welfare (MHLW).

Kissei has engaged in the research and development of new drugs focusing on rare diseases and diseases for which there are no sufficient treatments.