KYMRIAH® is a very powerful medicine. It is available only at specific treatment centers such as ours that have a Risk Evaluation and Mitigation Strategy in place. After a KYMRIAH® infusion, you or your child will remain in the hospital (or stay close by) until the risk for serious side effects wanes. In some cases, admission to the intensive care unit (ICU) is necessary.
In the study that led to FDA approval of KYMRIAH® for B-cell ALL, 84 percent of patients had severe or life-threatening adverse reactions. More recent data put that at 73 percent. In a study of patients with diffuse large B-cell lymphoma, 63 percent had severe or life-threatening adverse events believed to be caused by KYMRIAH.
The most common and dangerous side effect is cytokine release syndrome (CRS) — a strong, exaggerated immune reaction to the CAR-T cell therapy that causes inflammatory molecules (cytokines) to be rapidly released into the bloodstream. Also known as a “cytokine storm,” CRS can develop anywhere from several days to several weeks after the infusion. It can be effectively treated with a monoclonal antibody called tocilizumab (ACTEMRA), which the FDA approved together with KYMRIAH.
Other common side effects include:
- Hypogammaglobulinemia (low antibody levels), leading to an increased risk of infections
- Toxicity to the nervous system, including altered consciousness, confusion, agitation, seizures, balance problems, and difficulty speaking or understanding. This has been reported in 40 percent of patients.
- Decreased appetite, headache, a racing heart, nausea, diarrhea, vomiting, fatigue
- Low blood pressure
- Bleeding episodes
- Poor blood oxygenation
- Acute kidney injury