Real-Time Reporting Marks Major Shift in FDA Drug Safety Oversight

Pivoting toward more transparency regarding the adverse event profiles of pharmaceuticals, the FDA had begun real-time reporting of adverse events by way of the FDA Adverse Event Reporting System (FAERS).¹

“Having real-time data more quickly is always helpful for researchers, so this news is good to hear,” said Blood Cancers Today Editorial Board Member, Rahul Banerjee, MD, assistant professor, Clinical Research Division, Fred Hutch Cancer Center. “FAERS has many limitations as a source of data, most notably the lack of details or a denominator to calculate the incidence of toxicities. Nevertheless, it can be helpful for qualitative research or for toxicity comparisons between products. As such, real-time FAERS updates may be most helpful for researchers who are investigating emerging toxicities such as IEC-associated enterocolitis with chimeric antigen receptor [CAR] T-cell therapy,” he added.

CAR T-cell products may be especially important to monitor. In 2024, the FDA issued a class-wide box warning for B-cell maturation antigen-directed CAR T-cell therapies as well as CD19-directed CAR T-cell therapies due to the high potential for patients developing secondary T-cell malignancies.²

According to the latest report in FAERS³, of the FDA-approved CAR T-cell therapies for the treatment of lymphoma (axicabtagene ciloleucel, lisocabtagene maraleucel, and brexucabtagene autoleucel), there were 1,525 adverse event cases in 2025, accounting for 14.1% of all adverse events reported. Among the agents approved to treat multiple myeloma (ciltacabtagene autoleucel and idecabtagene vicleucel), FAERS shows 1,578 adverse event cases in 2025, representing 34.80% of all cases reported in this year. For tisagenlecleucel, the only approved CAR T agent for a leukemia, 337 cases had been reported in 2025 (8.83% of all cases).

Aside from CAR T, other drug classes can be concerning, including agents like chemotherapies and BTK inhibitors. For example, in 2025, 3,359 adverse event cases (15.01%) were associated with ibrutinib, acalabrutinib, zanubrutinib, or pirtobrutinib.³

According to the FDA, this change is part of modernizations within the agency.¹ Their goals are to streamline the collection of adverse event data, which can in turn identify serious errors with medicine and product quality. Experts question, however, if FAERS can do that efficiently.

“The FDA move to publish adverse event data from the FAERS on a daily basis will hopefully improve faster access to these data, with potential for rapid identification of safety signals—critical for patient safety and public confidence. However, we will have to be careful that the mere presence of an adverse event (without appropriate clinical context) does not necessarily establish causality. This obviously carries the risk of potential misinterpretation of data, leading to undue alarm,” said Mehdi Hamadani, MD, professor of medicine and chief of Hematologic Malignancies at the Medical College of Wisconsin and co-editor-in-chief of Blood Cancers Today.

FDA commissioner, Marty Makary, MD, MPH stated, “Adverse event reporting should be fast, seamless, and transparent. People who navigate the government’s clunky adverse event reporting websites should not have to wait months for that information to become public. We’re closing that waiting period and will continue to streamline the process from start to finish.”

The daily reporting system is now available to the public with data contributions from healthcare professionals, consumers, and drug manufacturers.