Timely Leukapheresis May Interfere with the “Fitness” of Lymphocytes Collected for CAR-T Treatment in High Risk DLBCL Patients

Abstract

The development of chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of hematological diseases. However, approximately 60% of patients relapse after CAR-T cell therapy, and no clear cause for this failure has been identified. The objective of the Bio-CAR-T BS study (ClinicalTrials.gov: NCT05366569) is to improve our understanding of the lymphocyte harvest to maximize the quality of the CAR-T cell product. Of the 14 patients enrolled, 11 were diagnosed with DLBCL, 2 with PMBCL, and 1 with ALL. Five of 11 DLBCL patients met the criteria for “pre-emptive” Lymphocytes-apheresis (being at high risk of second relapse), and 6 were included in the standard-of-care Lymphocytes-apheresis group. Previous autologous stem cell transplantation (ASCT) and age were significantly different between the two groups. At the time of Lymphocyte-apheresis, patients in the “pre-emptive” group had more “fit” lymphocytes (higher CD4+/CD8+ ratio; higher naïve T cells levels) compared with standard group, probably due to the impact of ASCT. At the same time, also being older than 60 years results in a more “exhausted” lymphocyte profile. Overall, “pre-emptive” Ly-apheresis in DLBCL patients at high risk of relapse appears to be feasible and may allow the timely collection of “fit” lymphocytes for CAR-T cell manufacturing.

Risk factors for CAR‐T cell manufacturing failure among DLBCL patients: A nationwide survey in Japan

“…While several groups have tried to evaluate T‐cell fitness by thorough analyses of T‐cell subsets, that is, naïve/stem cell memory, central memory, effector memory and effector T cells, or by quantifying cytokine production, 11–15 it has been difficult to evaluate T‐cell fitness in clinical practice. Because the CD4/CD8 ratio among T cells in peripheral blood declines with ablative chemotherapies, it is a convenient surrogate marker of T‐cell fitness 16–18 . In addition, as it has been reported that proliferation and therapeutic effects of CAR‐T cells are improved by a manufacturing process in which collected T cells were separated into CD4 + cells and CD8 + cells, and CAR was introduced with a balanced CD4/CD8 ratio, 19,20 our results suggest that the CD4/CD8 ratio of T cells may also affect efficiency of the subsequent manufacturing process.…”

“…Because the CD4/ CD8 ratio among T cells in peripheral blood declines with ablative chemotherapies, it is a convenient surrogate marker of T-cell fitness. [16][17][18] In addition, as it has been reported that proliferation and therapeutic effects of CAR-T cells are improved by a manufacturing process in which collected T cells were separated into CD4 + cells and CD8 + cells, and CAR was introduced with a balanced CD4/CD8 ratio, 19,20 our results suggest that the CD4/CD8 ratio of T cells may also affect efficiency of the subsequent manufacturing process. The adverse effect of an unfavourable CD4/CD8 ratio on CAR-T cell manufacturing may be minimized by optimizing the manufacturing process.…”

Challenges and solutions to superior chimeric antigen receptor‐T design and deployment for B‐cell lymphomas

“…In the Bio‐CAR‐T BS study, patients who received early pre‐emptive lymphocyte apheresis had a significantly different T cell population compared to those who underwent standard lymphocyte apheresis. Specifically, early T cell collection resulted in a higher CD4+/CD8+ ratio, higher CD4+ naive T cells, lower CD4+ effector memory T cells, and lower CD8+ terminally differentiated cell when compared to T cells collected in the standard group 43 …”

“…Specifically, early T cell collection resulted in a higher CD4+/CD8+ ratio, higher CD4+ naive T cells, lower CD4+ effector memory T cells, and lower CD8+ terminally differentiated cell when compared to T cells collected in the standard group. 43 Finally, a considerable challenge is that we do not have long-term follow-up data to know which clinical setting (i.e. line of therapy) is optimal for delivering CAR-T cells.…”

Engineering Improved CAR T Cell Products with A Multi‐Cytokine Particle Platform for Hematologic and Solid Tumors

“…[7,8] Accumulating evidence has shown that pre-infusion CAR T cell phenotypes, including exhaustion status and proportions of T cell differentiation subsets, can influence the durability of response. [9][10][11][12] The majority of current CAR T cell manufacturing processes do not consistently make products with high levels of lessdifferentiated T cells, such as central memory (T CM ) and stem cell-like memory (T SCM ), that are associated with durable responses in patients. [13][14][15][16][17] In fact, a recent phase I clinical trial enriching for naïve and memory phenotypes (CD62L+) before viral transduction allowed for lower doses of CAR T cell infusion and resulted in seven out of ten patients achieving complete response (CR) with durability at 18 months.…”