On 22 November 2024, Chugai (a Roche subsidiary) and Zenyaku Kogyo announced that their co-marketed Rituxan® (rituximab) has been approved by the Japanese Ministry of Health, Labour and Welfare for chronic idiopathic thrombocytopenic purpura (ITP) in children (IV injection, 100mg and 500mg). Rituxan® was previously approved in Japan for chronic ITP in adults only.
Rituximab is not currently approved in the US or EU for chronic ITP.
Genentech and Biogen collaborate on Rituxan® in the United States, and Roche markets the drug as MabThera® in the rest of the world, except Japan, where Rituxan® is co-marketed by Chugai and Zenyaku.
Rituximab was one of the first mAbs to become “biosimilar”. Both Pfizer and Sandoz/Kyowa Kirin market rituximab biosimilars in Japan. There are three rituximab biosimilars currently on the US market: Teva and Celltrion’s Truxima® (launched in May 2020), Pfizer’s Rituxience® (launched in January 2020) and Amgen and Allergan’s RiabniTM (approved by the FDA in December 2020).