One-Third Of Serious CAR-T Cell Therapy Side Effects Linked To Toxicity

Toxicity is likely responsible for one-third of all admissions to intensive care units (ICUs) for patients who have recently undergone cancer treatments involving chimeric antigen receptor T cell (CAR-T) therapy, according to the findings of a new study.

Researchers with the Mayo Clinic presented findings of a new study on CAR-T therapy side effects at the Society of Critical Care Medicine’s 50th Critical Care Congress Virtual Event earlier this month, indicating that one out of three ICU visits by CAR-T patients are linked to to two conditions: cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS).

Cytokine release syndrome is an overactive immune response which ranges from flu-like symptoms to life threatening complications, such as heart problems, acute respiratory distress or multiple organ failure. The researchers linked it to respiratory failure and end-organ damage.

ICANS use was linked to seizures, motor function problems and cerebral edema.

Researchers looked at data on 345 patients who underwent CAR-T therapy at 11 medical centers nationwide from November 2017 through May 2019. According to the findings, just under 33% were admitted to ICUs for either CRS or ICANS.

Of the 105 patients who went to ICU, 77% suffered CRS at some point during their time in the hospital, with 72% of the patients being diagnosed with CRS at the time of admission. Nearly 20% of the patients had both CRS and ICANS when first admitted to the ICU, and 80% of the patients had both CRS and ICANS during their hospital stay at some point.

Most patients were treated with the drug Actemra to treat CRS. Steroids were also often prescribed. However, 16 of the patients died, with most cases linked to infection and disease progression.

Actemra (tocilizumab) was introduced in 2010, as a second-line treatment for rheumatoid arthritis, in severe cases where individuals have not responded to other drugs. In May 2017, the FDA approved expanded use to treat giant cell arteritis, and the medication has grown to generate over $1.6 billion in annual sales.

However, critics have expressed concerns about more serious side effects of Actemra, which were not adequately disclosed on the drug’s label.

Unlike other competing rheumatoid arthritis drugs, Actemra warnings do not include information about certain health risks linked to competing treatments, such as Humira, Remicade and Enbrel. Therefore, many doctors and consumers are under the impression that Actemra is safer. However, reports in recent years suggest users may face the same, or higher risks.