CAR-T product development: an assessment of FDA’s final guidance for industry

The FDA released its final industry guidance for CAR-T developers on January 29, following a draft published in March 2022. Experts from Parexel Regulatory Strategy, including ex-FDA and EMA regulators, share their insight into the guidance’s clinical, non-clinical and CMC recommendations.  

CAR T-cells are gene therapy products regulated under FDA’s existing framework for biological products. The agency recognizes the specific complexity and challenge of development in this space, with this document offering recommendations to further guide sponsors. It focuses on oncology indications, including hematologic malignancies and solid tumors without explicitly addressing other treatment areas, such as autoimmune diseases. Considerations for “non-traditional” indications are still being studied and may possess significantly different benefit-risk considerations due to concerns of secondary T-cell malignancy. 

Notably, the guidance does not specifically mention the recent FDA investigation into secondary T-cell malignancies in patients treated with approved CAR-T products. This absence indicates that the FDA is still interpreting and assessing the findings. Nonetheless, the content of the guidance does not imply a significant change in the FDA's benefit-risk assessment for CAR-Ts. For instance, the recommended long-term follow-up (LTFU) duration of 15 years for patients who have received CAR-Ts manufactured using integrating vectors remains unchanged in the final guidance, compared to the draft guidance that preceded the recent T-cell malignancy issue. 

Overall, this guidance balances class-wide regulatory considerations for CAR-Ts, while emphasizing the importance of individualized FDA review of benefit-risk, based on the unique characteristics of each investigational CAR-T product/indication.