(P-BT-21) The beginning of CAR T- cell in Brazil: apheresis for T-cell collection in pediatric and adult patients

Background/Case Studies: Chimeric antigen receptor (CAR) T-cell therapy is spreading hope all around the world for patients suffering from acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBL), providing for blood banks and cell processing centers a new challenge: collect lymphocytes from refractory, in second or later relapse patients where leukapheresis can be laborious due to their condition, but a successful collection is mandatory for effective manufacturing and treatment. Although this therapy has been done in many countries, in Brazil, it started in 2022. Our centers performed the first apheresis for CAR-T in Oct.2022. This study aimed to share our experience with apheresis and cell processing in successful collection of T-cells for CAR T-cell therapy in adults and pediatric patients.

Study

Design/Methods: Data was collected from 21 leukapheresis aimed for CAR T-cell therapy with Tisagenlecleucel™ in 3 centers located in the south and southeast of Brazil. Between Oct. 2022 and Apr. 2023 we conducted 5 leukapheresis in patients with ALL and 11 with DLBL. Spectra Optia®, Terumo BCT, was employed for apheresis using the cMNC cell program. Apheresis success specification: total nucleated cell (TNC) count ≥2x109, CD3-positive lymphocyte counts ≥1x109 and ≥3% of T-cells in the product. Depending on the patient's venous anatomy, lymphocyte collection was through a central venous catheter access or a peripheral line.

Results/Findings: In this study we evaluated 16 patients and 21 apheresis run, 02 patients (1 adult and 1 pediatric) required 03 leukapheresis session and 01 adult patient a second leukapheresis session. Blood prime was required in 5 pediatric patients. No serious side-effects associated with leukapheresis were observed and all procedures were successful. Table 01 express results from patients, leukapheresis and product.

Conclusions: Our study included pediatric and adult patients who had two categories of diagnosis ALL and DLBL. Leukapheresis for CAR T-cell did not cause any serious side effects and enough quantity of CD3 positive lymphocytes for CAR T-cell production was collected despite heavy pretreatment and disease. The continuous evaluation of these emerging data will be critical to improving the outcomes of patients receiving CAR T-cell therapy.

Importance of research: Apheresis leucocyte collection is an expertise for blood bank professionals and it is an important step for Car T manufactuting. Car T started in Brazil in 2022. This study brings data from 3 centers in Brazil, that are part of the same Group, Grupo Vita, demonstrating results from Apheresis leucocyte collection in adult and pediatric patients with LLA or DLBL,without serious side effects and a good number of CD3 lymphocytes for CAR T-cell production.