Manufacturing chimeric antigen receptor T cells: issues and challenges

Clinical trials of adoptively transferred CD19 chimeric antigen receptor (CAR) T cells have delivered unprecedented responses in patients with relapsed refractory B-cell malignancy. These results have prompted Food and Drug Administration (FDA) approval of two CAR T-cell products in this high-risk patient population. The widening range of indications for CAR T-cell therapy and increasing patient numbers present a significant logistical challenge to manufacturers aiming for reproducible delivery systems for high-quality clinical CAR T-cell products. This review discusses current and novel CAR T-cell processing methodologies and the quality control systems needed to meet the increasing clinical demand for these exciting new therapies.

Validation of the single-platform ISHAGE protocol for enumeration of CD34+ hematopoietic stem cells in umbilical cord blood in a Brazilian center

Background

This study aims to validate the single-platform method for enumeration of CD34+ cells, by comparing the performance of two different commercial kits, as well as to evaluate the efficiency of the Accuri^TM C6 cytometer in providing direct counts of absolute cell numbers.

Method

We evaluated 20 samples from umbilical cord blood (UCB), comparing the two different methodologies for enumeration of CD34+ cells: single and dual-platform. For the assessment of the single-platform, Procount and SCE kits were used, both of which use fluorescent beads as a counting reference to obtain absolute CD34+ cells numbers. Moreover, after the acquisition of samples in flow cytometer Accuri^TM C6, following the protocol established for each kit, the number of CD34+ cells was recalculated, considering the cell count provided by the Accuri^TM C6.

Main Results

In our analysis, the results showed a strong correlation between the number of CD34+ cells/μL (r² = 0.77) when comparing the SCE kit and the current dual-platform method. On the other hand, the comparison between Procount kit and dual-platform results showed a moderate correlation for the number of CD34+/μL cells (r² = 0.64).

Conclusion

Our results showed that the Accuri^TM C6 flow cytometer can be used safely, applying both the dual and single platform analysis strategy. Considering the ISHAGE protocol-based single-platform approach, as the most appropriate methodology for CD34+ cells enumeration, our results demonstrated that the SCE kit has great potential for national standardization of UCB samples analysis methodology.

AKT inhibition generates potent polyfunctional clinical grade AUTO1 CAR T-cells, enhancing function and survival

BACKGROUND

AUTO1 is a fast off-rate CD19-targeting chimeric antigen receptor (CAR), which has been successfully tested in adult lymphoblastic leukemia. Tscm/Tcm-enriched CAR-T populations confer the best expansion and persistence, but Tscm/Tcm numbers are poor in heavily pretreated adult patients. To improve this, we evaluate the use of AKT inhibitor (VIII) with the aim of uncoupling T-cell expansion from differentiation, to enrich Tscm/Tcm subsets.

METHODS

VIII was incorporated into the AUTO1 manufacturing process based on the semiautomated the CliniMACS Prodigy platform at both small and cGMP scale.

RESULTS

AUTO1 manufactured with VIII showed Tscm/Tcm enrichment, improved expansion and cytotoxicity in vitro and superior antitumor activity in vivo. Further, VIII induced AUTO1 Th1/Th17 skewing, increased polyfunctionality, and conferred a unique metabolic profile and a novel signature for autophagy to support enhanced expansion and cytotoxicity. We show that VIII-cultured AUTO1 products from B-ALL patients on the ALLCAR19 study possess superior phenotype, metabolism, and function than parallel control products and that VIII-based manufacture is scalable to cGMP.

CONCLUSION

Ultimately, AUTO1 generated with VIII may begin to overcome the product specific factors contributing to CD19+relapse.