The Saitama Children's Medical Center has reported that one male teenager died after receiving chemotherapy, while two other male patients, one under 10 years old and another in their teens, have been left with severe long-term effects. The deaths have raised serious concerns about the administration of the treatment, as an analysis found a different drug that should not have been used in the chemotherapy process. The center has notified the police about the incident on the 10th of this month.

Following the chemotherapy injections meant to treat leukemia, all three patients exhibited unusual symptoms, such as loss of mobility. The deceased teenager reportedly developed thigh pain the day after the injection on October 22nd last year, eventually leading to his death on February 6th of this year. The two surviving patients, who received the same injection in January and March of last year, are currently on ventilators as they continue to receive treatment following their adverse reactions.

In response to the incident, the medical center suspended all chemotherapy injections from November last year and established an investigative committee to examine the administration processes. While the committee conducted an investigation into the treatment procedures without finding any issues, they later commissioned an analysis of patient samples, which revealed the presence of an unauthorized drug that has now been suggested as the likely cause of the complications experienced by the young patients.