Kissei Pharmaceutical Co., Ltd., based in Matsumoto City, Nagano Prefecture, announced on 18/5 that approximately 20 patients in Japan died after using Tabneos, a vasculitis drug available in the domestic market, according to Nikkei.
Post-marketing surveillance for the drug identified 22 cases of "vanishing bile duct syndrome", a condition that destroys bile ducts in the liver. Among the 20 deceased patients, 13 had developed this syndrome. Many cases manifested within the first three months of starting the medication. The Ministry of Health is investigating and has not yet reached a final conclusion regarding the cause of death.
Currently, about 8,500 patients in Japan use Tabneos. On 1/5, Kissei added "vanishing bile duct syndrome" to its list of serious side effects, specifically under liver dysfunction.
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The vasculitis drug Tabneos. Photo: Kissei
Japan's national health regulatory agency has not revoked Tabneos' marketing authorization but has suspended its prescription for new patients. Authorities also recommend doctors carefully consider whether current patients should continue or discontinue their treatment.
Kissei stated that it has always provided full information on side effects immediately after incidents occurred. The company is also directly discussing a response plan with Japan's Ministry of Health, Labor and Welfare.
Globally, health authorities have also taken decisive action regarding Tabneos. On 27/4, the Center for Drug Evaluation and Research, part of the US Food and Drug Administration (FDA), proposed revoking the product's marketing authorization in the US. The agency suspects the developer manipulated data and concealed information during clinical trials.
Previously, on 30/1, the European Medicines Agency (EMA) also reviewed the drug due to concerns about inconsistencies in late-stage trial data.
ChemoCentryx, a subsidiary of the US-based Amgen group, developed Tabneos from its early stages. In 2017, Kissei acquired exclusive commercial rights for Japan from a Swiss partner and participated in international clinical trials. The company officially launched the product in the domestic market in 6/2022 after submitting an application for approval based on earlier trial results.
