- Zenyaku obtained approval for Rituxan's use in autoimmune hemolytic anemia on February 19, 2026.
- The approval followed a public knowledge-based application submitted on August 29, 2025.
- AIHA involves autoantibodies causing red blood cell destruction, classified into warm AIHA, CAD, and PCH.
- Rituxan targets CD20 on B cells, reducing autoantibodies and offering an alternative to steroids.
Approval and Application
Zenyaku Kogyo Co., Ltd. and Chugai Pharmaceutical Co., Ltd. announced the approval of Rituxan for treating autoimmune hemolytic anemia (AIHA) by Japan's Ministry of Health, Labour and Welfare. The approval followed a public knowledge-based application submitted on August 29, 2025, after evaluation by the Japanese Society of Hematology and the Japanese Society of Pediatric Hematology/Oncology.
Understanding AIHA
AIHA is characterized by the production of autoantibodies that attack red blood cells, leading to their destruction. It is classified into warm AIHA, where autoantibodies react at body temperature, and cold AIHA, including cold agglutinin disease (CAD) and paroxysmal cold hemoglobinuria (PCH), which react at lower temperatures. Factors such as infections, immune system dysregulation, and drugs contribute to AIHA's etiology.
Treatment Options
For warm AIHA, adrenocortical steroids are effective in about 80% of cases, but relapses are common, often necessitating long-term treatment or splenectomy. CAD treatment focuses on maintaining warmth, though severe symptoms may require additional interventions. Rituxan is recommended in clinical guidelines as a treatment option for AIHA, particularly in cases resistant to steroids.
Mechanism of Rituxan
Rituxan is an anti-CD20 monoclonal antibody that targets B cells, excluding hematopoietic stem cells and plasma cells. It works by depleting B cells, which are involved in the production of autoantibodies. This mechanism is beneficial in AIHA, where autoreactive B cells contribute to the disease's progression.
