The US Food and Drug Administration (FDA)-mandated monitoring time for CAR-T therapy patients could be halved, according to a new study.

Chimeric antigen receptor (CAR)-T therapy involves modifying a patient’s T cells to recognise and attack cancer cells. There are three approved therapies to treat diffuse large B-cell non-Hodgkin lymphoma (DLBCL), notably Gilead’s Yescarta (axicabtagene ciloleucel) and Novartis’s Kymriah (tisagenlecleucel), which were approved by the FDA in 2017; and Bristol Myers Squibb’s Breyanzi (lisocabtagene maraleucel), which won approval in 2021.

Safety concerns surrounding CAR-T cell therapies related to cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS), led to strict FDA-mandated monitoring requirements when the therapies were first approved in 2017.

To allow for the safe use of these therapies, the FDA established a risk evaluation and mitigation strategy (REMS) programme, which covered these monitoring requirements. Under the REMS programme, patients need to stay near the treatment centre for four weeks and bar them from driving for eight weeks. This has created barriers for patients belonging to a lower socioeconomic status to access these therapies, according to the lead author of the study, Dr Nausheen Ahmed, associate professor of hematologic malignancies and cellular therapeutics, University of Kansas Medical Center.

The research study, published today in Blood Advances journal, found that the risk of CRS and ICANS peak by two weeks for lymphoma patients receiving certain CAR-T therapies. This suggests that the monitoring period could be made more flexible depending on individual patient needs, and possibly reduced from the current four-week period.

The study evaluated 475 patients with DLBCL. Of these patients, 216 received Yescarta, 158 Kymriah, and 100 Breyanzi. Overall, 60% experienced CRS and 32.4% experienced ICANS. In the first seven days, new-onset CRS occurred in 57.5% of patients and ICANS in 25.4% of patients. Between days eight and 12, new cases of CRS and ICANS were noted in 5.4% and 9.3% of patients, respectively. After 12 days, no new CRS cases and only one new ICANS case in a Kymriah recipient were reported.

Ahmed explained that making the monitoring period more flexible could improve accessibility for disadvantaged patients, save resources for treatment centres, and allow patients to resume their normal lives and responsibilities sooner.  

“In terms of resources, it would allow the treatment centres to have less of a burden. It will benefit the treatment centres in the fact that they can have early discharge, with patients going back home where they can see their referring doctor,” explained Ahmed.

Ahmed also led another study which demonstrated similar findings of 129 relapsed-refractory multiple myeloma patients on Bristol Myers Squibb’s Abecma (idecabtagene vicleucel), and Johnson & Johnson’s Carvykti (ciltacabtagene autoleucel).

Ahmed also emphasised the importance of empowering and educating community doctors to take a larger role in monitoring and treating long-term side effects of CAR-T therapies.  

“The major cause of death in the first three months is actually infection. The focus has to be on really empowering and teaching and collaborating with our community doctors because patients can still die of complications, but the complication is more than likely going to be infection,” concluded Ahmed.  

In addition to infection, the FDA launched an investigation in November 2023, following reports of secondary cancers in some patients that have received CAR-T therapy. As well as the investigation, the FDA added boxed warnings for secondary T-cell malignancies to all approved CAR-T therapies.