Factors affecting lymphocyte collection efficiency for the manufacture of chimeric antigen receptor T cells in adults with B-cell malignancies

The effect of physical exercise on anticancer immunity

Regular physical activity is associated with lower cancer incidence and mortality, as well as with a lower rate of tumour recurrence. The epidemiological evidence is supported by preclinical studies in animal models showing that regular exercise delays the progression of cancer, including highly aggressive malignancies. Although the mechanisms underlying the antitumorigenic effects of exercise remain to be defined, an improvement in cancer immunosurveillance is likely important, with different immune cell subtypes stimulated by exercise to infiltrate tumours. There is also evidence that immune cells from blood collected after an exercise bout could be used as adoptive cell therapy for cancer. In this Perspective, we address the importance of muscular activity for maintaining a healthy immune system and discuss the effects of a single bout of exercise (that is, 'acute' exercise) and those of 'regular' exercise (that is, repeated bouts) on anticancer immunity, including tumour infiltrates. We also address the postulated mechanisms and the clinical implications of this emerging area of research.

Autologous anti-GD2 CAR T cells efficiently target primary human glioblastoma

Glioblastoma (GBM) remains a deadly tumor. Treatment with chemo-radiotherapy and corticosteroids is known to impair the functionality of lymphocytes, potentially compromising the development of autologous CAR T cell therapies. We here generated pre-clinical investigations of autologous anti-GD2 CAR T cells tested against 2D and 3D models of GBM primary cells. We detected a robust antitumor effect, highlighting the feasibility of developing an autologous anti-GD2 CAR T cell-based therapy for GBM patients.

Managing leukapheresis in adult and pediatric patients eligible for chimeric antigen receptor T-cell therapy: suggestions from an Italian Expert Panel

Chimeric antigen receptor (CAR) T-cell therapy relies on T cells engineered to target specific tumor antigens such as CD-19 in B-cell malignancies. In this setting, the commercially available products have offered a potential long-term cure for both pediatric and adult patients. Yet manufacturing CAR T cells is a cumbersome, multistep process, the success of which strictly depends on the characteristics of the starting material, i.e., lymphocyte collection yield and composition. These, in turn, might be affected by patient factors such as age, performance status, comorbidities, and previous therapies. Ideally, CAR T-cell therapies are a one-off treatment; therefore, optimization and the possible standardization of the leukapheresis procedure is critical, also in view of the novel CAR T cells currently under investigation for hematological malignancies and solid tumors. The most recent Best Practice recommendations for the management of children and adults undergoing CAR T-cell therapy provide a comprehensive guide to their use. However, their application in local practice is not straightforward and some grey areas remain. An Italian Expert Panel of apheresis specialists and hematologists from the centers authorized to administer CAR T-cell therapy took part in a detailed discussion on the following: 1) pre-apheresis patient evaluation; 2) management of the leukapheresis procedure, also in special situations represented by low lymphocyte count, peripheral blastosis, pediatric population <25 kg, and the COVID-19 outbreak; and 3) release and cryopreservation of the apheresis unit. This article presents some of the important challenges that must be faced to optimize the leukapheresis procedure and offers suggestions as to how to improve it, some of which are specific to the Italian setting.

A novel predictive algorithm to personalize autologous T-cell harvest for chimeric antigen receptor T-cell manufacture

BACKGROUND AIMS

The most widely accepted starting materials for chimeric antigen receptor T-cell manufacture are autologous CD3+ T cells obtained via the process of leukapheresis, also known as T-cell harvest. As this treatment modality gains momentum and apheresis units struggle to meet demand for harvest slots, strategies to streamline this critical step are warranted.

METHODS

This retrospective review of 262 T-cell harvests, with a control cohort of healthy donors, analyzed the parameters impacting CD3+ T-cell yield in adults with B-cell malignancies. The overall aim was to design a novel predictive algorithm to guide the required processed blood volume (PBV) (L) on the apheresis machine to achieve a specific CD3+ target yield.

RESULTS

Factors associated with CD3+ T-cell yield on multivariate analysis included peripheral blood CD3+ count (natural log, ×109/L), hematocrit (HCT) and PBV with coefficients of 0.86 (95% confidence interval [CI], 0.80-0.92, P < 0.001), 1.30 (95% CI, 0.51-2.08, P = 0.001) and 0.09 (95% CI, 0.07-0.11, P < 0.001), respectively. The authors' model, incorporating CD3+ cell count, HCT and PBV (L), with an adjusted R2 of 0.87 and root-mean-square error of 0.26 in the training dataset, was highly predictive of CD3+ cell yield in the testing dataset. An online application to estimate PBV using this algorithm can be accessed at https://cd3yield.shinyapps.io/cd3yield/.

CONCLUSIONS

The authors propose a transferrable model that incorporates clinical and laboratory variables accessible pre-harvest for use across the field of T-cell therapy. Pending further validation, such a model may be used to generate an individual leukapheresis plan and streamline the process of cell harvest, a well-recognized bottleneck in the industry.

Evaluation of cell collection efficiency in non-mobilized adult donors for autologous chimeric antigen receptor T-cell manufacturing

BACKGROUND AND OBJECTIVES

Data about collection efficiency 1 (CE1), which takes into account blood cell counts before and after collection, thus providing a more accurate estimate, in the collection of autologous T lymphocytes by apheresis for chimeric antigen receptor (CAR) T-cells remain scarce. We evaluated donor- and procedure-related characteristics that might influence the CE1 of lymphocytes.

MATERIALS AND METHODS

We retrospectively reviewed all mononuclear cell (MNC) collections) performed for CAR T-cell manufacturing in our institution from May 2017 to June 2021 in adult patients. Age, gender, weight, total blood volume (TBV), prior haematopoietic cell transplant, diagnosis, days between last treatment and apheresis, pre-collection cell counts, duration of apheresis, TBV processed, vascular access, inlet flow and device type were analysed as potential factors affecting CE1 of lymphocytes.

RESULTS

A total of 127 autologous MNC collections were performed on 118 patients diagnosed with acute lymphoblastic leukaemia (n = 53, 45%), non-Hodgkin lymphoma (n = 40, 34%), multiple myeloma (n = 19, 16%), and chronic lymphocytic leukaemia (n = 6, 5%). The median CE1 of lymphocytes was 47% (interquartile range: 32%-65%). In multiple regression analysis, Amicus device was associated with higher CE1 of lymphocytes (p = 0.01) and lower CE1 of platelets (p < 0.01) when compared with Optia device.

CONCLUSION

The knowledge of the MNC and lymphocyte CE1 of each apheresis device used to collect cells for CAR T therapy, together with the goal of the number of cells required, is essential to define the volume to be processed and to ensure the success of the collection.

Leukapheresis guidance and best practices for optimal chimeric antigen receptor T-cell manufacturing

Chimeric antigen receptor (CAR) T-cell therapy is an individualized immunotherapy that genetically reprograms a patient's T cells to target and eliminate cancer cells. Tisagenlecleucel is a US Food and Drug Administration-approved CD19-directed CAR T-cell therapy for patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia and r/r diffuse large B-cell lymphoma. Manufacturing CAR T cells is an intricate process that begins with leukapheresis to obtain T cells from the patient's peripheral blood. An optimal leukapheresis product is essential to the success of CAR T-cell therapy; therefore, understanding factors that may affect the quality or T-cell content is imperative. CAR T-cell therapy requires detailed organization throughout the entire multistep process, including appropriate training of a multidisciplinary team in leukapheresis collection, cell processing, timing and coordination with manufacturing and administration to achieve suitable patient care. Consideration of logistical parameters, including leukapheresis timing, location and patient availability, when clinically evaluating the patient and the trajectory of their disease progression must be reflected in the overall collection strategy. Challenges of obtaining optimal leukapheresis product for CAR T-cell manufacturing include vascular access for smaller patients, achieving sufficient T-cell yield, eliminating contaminating cell types in the leukapheresis product, determining appropriate washout periods for medication and managing adverse events at collection. In this review, the authors provide recommendations on navigating CAR T-cell therapy and leukapheresis based on experience and data from tisagenlecleucel manufacturing in clinical trials and the real-world setting.

A clinically applicable prediction model to improve T-cell collection in CAR-T cell therapy

As chimeric antigen receptor T (CAR-T) cell therapy targeting CD19 has shown favorable outcomes in patients with relapsed or refractory (r/r) mature B-cell lymphomas and B-cell acute lymphoblastic leukemia (B-ALL), the number of patients who are waiting to receive these treatments is increasing. Optimized protocols for T-cell collection by lymphapheresis for chimeric antigen receptor (CAR) -T cell therapy must be urgently established to provide CAR-T cell therapy for patients with refractory and progressive disease, and/or a low number of lymphocytes due to prior chemotherapies. Predicted collection efficiency of CD3⁺ cells in apheresis can guide protocols for apheresis, but a clinically applicable model to produce reliable estimates has not been established yet. Therefore, we prospectively analyzed lymphapheresis procedures for tisagenlecleucel therapy at two centers. A total of 108 apheresis procedures included 20 procedures for patients with B-cell acute lymphoblastic leukemia, and 88 for patients with diffuse large B-cell lymphoma, with a median age at apheresis of 58 years (1-71). After lymphapheresis with a median processing blood volume of 10 L (3-16), a median of 3.2 × 10⁹ (0.1-15.0) CD3⁺ cells were harvested. Collection efficiency 2 (CE2) for CD3⁺ cells was highly variable (median, 59.3%; range 11.0-199.8). Multivariate analyses revealed that lower Hgb levels, higher circulating CD3⁺ cell counts, and higher platelet counts before apheresis significantly decreased apheresis CE2. Based on multivariate analyses, we developed a novel formula that estimates CE2 from pre-collection parameters with high accuracy (r = 0.56, p < 0.01), which also suggests the necessary processing blood volume. Our strategy in lymphapheresis should be helpful to reduce collection failure, as well as to achieve efficient utilization of medical resources in clinical practice, thereby delivering CAR-T cell therapy to more patients in a timely manner.

CAR T Cells

In 1891, Dr. William B. Coley, an American surgeon, made a compelling observation that immune system can be triggered to shrink tumors. The quest to exploit the power of immunotherapy however was forestalled by an era of chemotherapy that ensued. During World War II, the accidental sinking of a US naval ship led to a group of sailors developing pancytopenia due to poisoning from mustard gas (nitrogen mustard). The observation prompted wide-scale screening of these chemical compounds with cytotoxic potential; further clinical trials led to the first Food and Drug Administration (FDA) approval of a chemotherapy drug, nitrogen mustard. Immunotherapy field took further impetus, not until the last two decades, due to our deeper understanding of the immune system and the cellular and molecular pathways leading to tumor development. Two groundbreaking therapies which have shown great promise in this field involve "taking the breaks off" and "pushing the pedal" of the immune system. These therapies, namely, immune checkpoint inhibitors and adoptive cell therapy, respectively, have been successful in a variety of malignancies, while the former mostly in solid tumors and the latter in hematological malignancies.

T Cell Fitness and Autologous CAR T Cell Therapy in Haematologic Malignancy

A range of emerging therapeutic approaches for the treatment of cancer aim to induce or augment endogenous T cell responses. Chimeric antigen receptor (CAR) T cell therapy (CTT) is one such approach that utilises the patient’s own T cells, engineered ex vivo to target cell surface antigens, to eliminate haematological malignancies. Despite mediating high rates of responses in some clinical trials, this approach can be limited by dysfunctional T cells if they are present at high frequencies either in the starting material from the patient or the CAR T cell product. The fitness of an individual’s T cells, driven by age, chronic infection, disease burden and cancer treatment, is therefore likely to be a crucial limiting factor of CTT. Currently, T cell dysfunction and its impact on CTT is not specifically quantified when patients are considering the therapy. Here, we review our current understanding of T cell fitness for CTT, how fitness may be impacted by age, chronic infection, malignancy, and treatment. Finally, we explore options to specifically tailor clinical decision-making and the CTT protocol for patients with more extensive dysfunction to improve treatment efficacy. A greater understanding of T cell fitness throughout a patient’s treatment course could ultimately be used to identify patients likely to achieve favourable CTT outcomes and improve methods for T cell collection and CTT delivery.

Culturing adequate CAR-T cells from less peripheral blood to treat B-cell malignancies

OBJECTIVE

Chimeric antigen receptor-modified T (CAR-T) cells have shown impressive results against relapsed/refractory B cell malignancies. However, the traditional manufacture of CAR-T cells requires leukapheresis to isolate large amounts of peripheral blood T cells, thus making some patients ineligible for the procedure.

METHODS

We developed a simple method for CAR-T cell preparation requiring small volumes of peripheral blood. First, CD3+ T cells isolated from 50 mL peripheral blood from patients (B-cell malignancies) were stimulated with immobilized anti-CD3/RetroNectin in 6-well plates and then transduced with CAR-expressing lentiviral vector. After 4 d, the T cells were transferred to culture bags for large-scale CAR-T cell expansion. In vitro and animal experiments were performed to evaluate the activity of the manufactured CAR-T cells. Finally, 29 patients with B-cell acute lymphoblastic leukemia (B-ALL) and 9 patients with B-cell lymphoma were treated with the CAR-T cells.

RESULTS

The CAR-T cells were expanded to 1-3 × 108 cells in 8-10 d and successfully killed B cell-derived malignant tumor cells in vitro and in vivo. For patients with B-ALL, the complete remission rate was 93% 1 month after CAR-T cell infusion; after 12 months, the overall survival (OS) and leukemia-free survival rates were 69% and 31%, respectively. For patients with lymphoma, the objective response rate (including complete and partial remission) was 78% 2 months after CAR-T cell infusion, and after 12 months, the OS and progression-free survival rates were 71% and 43%, respectively. Cytokine-release syndrome (CRS) occurred in 65.51% and 55.56% of patients with B-ALL and B-cell lymphoma, respectively; severe CRS developed in 20.69% of patients with B-ALL and in no patients with lymphoma.

CONCLUSIONS

Our novel method can generate sufficient numbers of CAR-T cells for clinical use from 50-100 mL peripheral blood, thus providing an alternative means of CAR-T cell generation for patients ineligible for leukapheresis.

Optimization of lymphapheresis for manufacturing autologous CAR-T cells

Collection of CD3+ lymphocytes via lymphapheresis is essential for manufacturing autologous chimeric antigen receptor (CAR) T cells. Optimization of timing and procedures for lymphapheresis for each patient is critical because patients often have progressive diseases and receive medications that could reduce T cell counts. We conducted a retrospective study of clinical data from 28 patients who underwent lymphapheresis for CD19-directed CAR-T therapy with tisagenlecleucel to identify factors that could affect CD3+ lymphocyte yields. The numbers of CD3+ cells in peripheral blood were significantly correlated with CD3+ cell yields (correlation coefficient r = 0.84), which enabled us to estimate the volume of blood to process before apheresis. We also found that small cell ratio (SCR) at the apheresis site precisely reflected the proportion of lymphocytes, especially in patients without circulating blasts (coefficient of determination: r² = 0.9). We were able to predict the CD3+ cell yield and prevent excessive apheresis by measuring pre-apheresis circulating CD3+ cell counts and monitoring SCR. Collectively, these results will help us to establish a strategy for optimization of lymphapheresis procedures for CAR-T cell production on a patient-by-patient basis.

Exercise and the immune system: taking steps to improve responses to cancer immunotherapy

The remarkable success of cancer immunotherapies has provided new hope to cancer patients. Unfortunately, a significant proportion of patients remain unable to respond to immunotherapy or maintain durable clinical responses. The lack of objective responses likely results from profound immune dysfunction often observed in patients with cancer. There is substantial evidence that exercise and physical activity can reduce incidence and improve outcomes in cancer patients. As the immune system is highly responsive to exercise, one potential avenue to improve immune function is through exercise and physical activity. A single event of dynamic exercise results in the substantial mobilization of leukocytes with increased functional capacities into the circulation. Chronic, or long-term, exercise leads to higher physical fitness in terms of greater cardiorespiratory function and/or muscle strength and endurance. High aerobic capacity, as measured by maximal oxygen uptake, has been associated with the reduction of dysfunctional T cells and improvements in the abundance of some T cell populations. To be sure, however, the mechanisms of exercise-mediated immune changes are both extensive and diverse. Here, we examine the evidence and theorize how acute and chronic exercise could be used to improve responses to cancer immunotherapies including immune checkpoint inhibitors, dendritic cell vaccines, natural killer cell therapies, and adoptive T cell therapies such as chimeric antigen receptor (CAR) T cells. Although the parameters of optimal exercise to yield defined outcomes remain to be determined, the available current data provide a compelling justification for additional human studies and clinical trials investigating the adjuvant use of exercise in immuno-oncology.

Optimizing leukapheresis product yield and purity for blood cell-based gene and immune effector cell therapy

PURPOSE OF REVIEW

A critical common step for blood-based ex-vivo gene and immune effector cell (IEC) therapies is the collection of target cells for further processing and manufacturing, often accomplished through a leukapheresis procedure to collect mononuclear cells (MNCs). The purpose of this review is to describe strategies to optimize the apheresis product cell yield and purity for gene and IEC therapies. Relevant data from the conventional bone marrow transplant literature is described where applicable.

RECENT FINDINGS

Product yield is affected by three main factors: the peripheral blood concentration of the target cell, optimized by mobilizing agents, donor interventions or donor selection; the volume of peripheral blood processed, tailored to the desired product yield using prediction algorithms; and target cell collection efficiency, optimized by a variety of device and donor-specific considerations. Factors affecting product purity include characteristics of the donor, mobilizing agent, device, and device settings.

SUMMARY

Strategies to optimize product yield and purity for gene and IEC therapies are important to consider because of loss of target cell numbers or function with downstream steps and detrimental effects of nontarget cells on further manufacturing and patient outcome.

Chimeric antigen receptor T-cell therapies: Optimising the dose

Lymphocytes such as T-cells can be genetically transduced to express a synthetic chimeric antigen receptor (CAR) that re-directs their cytotoxic activity against a tumour-expressed antigen of choice. Autologous (patient-derived) CAR T-cells have been licensed to treat certain relapsed and refractory B-cell malignancies, and numerous CAR T-cell products are in clinical development. As living gene-modified cells, CAR T-cells exhibit unique pharmacokinetics, typically proliferating within the recipient during the first 14 days after administration before contracting in number, and sometimes exhibiting long-term persistence. The relationship between CAR T-cell dose and exposure is highly variable, and may be influenced by CAR design, patient immune function at the time of T-cell harvest, phenotype of the CAR T-cell product, disease burden, lymphodepleting chemotherapy and subsequent immunomodulatory therapies. Recommended CAR T-cell doses are typically established for a specific product and indication, although for some products, stratification of dose based on disease burden may mitigate toxicity while maintaining efficacy. Re-evaluation of CAR T-cell dosing may be necessary following changes to the lymphodepleting regimen, for different disease indications, and following significant manufacturing changes, if product comparability cannot be demonstrated. Dose escalation trials have typically employed 3 + 3 designs, although this approach has limitations, and alternative phase I trial designs may facilitate the identification of CAR T-cell doses that strike an optimal balance of safety, efficacy and manufacturing feasibility.

Unstimulated apheresis for chimeric antigen receptor manufacturing in pediatric/adolescent acute lymphoblastic leukemia patients

Autologous unstimulated leukapheresis product serves as starting material for a variety of innovative cell therapy products, including chimeric antigen receptor (CAR)-modified T-cells. Although it may be reasonable to assume feasibility and efficiency of apheresis for CAR-T cell manufacture, several idiosyncrasies of these patients warrant their separate analysis: target cells (mononuclear cells [MNC] and T-cells) are relatively few which may instruct the selection of apheresis technology, low body weight, and, hence, low total blood volume (TBV) can restrict process and product volume, and patients may be in compromised health. We here report outcome data from 46 consecutive leukaphereses in 33 unique pediatric patients performed for the purpose of CD19-CAR-T-cell manufacturing. Apheresis targets of 2×10⁹ MNC/1×10⁹ T-cells were defined by marketing authorization holder specification. Patient weight was 8 to 84 kg; TBV was 0.6 to 5.1 L. Spectra Optia apheresis technology was used. For 23 patients, a single apheresis sufficed to generate enough cells and manufacture CAR-T-cells, the remainder required two aphereses to meet target dose and/or two apheresis series because of production failure. Aphereses were technically feasible and clinically tolerable without serious adverse effects. The median collection efficiencies for MNC and T-cells were 53% and 56%, respectively. In summary, CAR apheresis in pediatric patients, including the very young, is feasible, safe and efficient, but the specified cell dose targets can be challenging in smaller children. Continuous monitoring of apheresis outcomes is advocated in order to maintain quality.

Next-Generation Manufacturing Protocols Enriching TSCM CAR T Cells Can Overcome Disease-Specific T Cell Defects in Cancer Patients

Chimeric antigen receptor (CAR) T cell expansion and persistence emerged as key efficacy determinants in cancer patients. These features are typical of early-memory T cells, which can be enriched with specific manufacturing procedures, providing signal one and signal two in the proper steric conformation and in the presence of homeostatic cytokines. In this project, we exploited our expertise with paramagnetic beads and IL-7/IL-15 to develop an optimized protocol for CAR T cell production based on reagents, including a polymeric nanomatrix, which are compatible with automated manufacturing via the CliniMACS Prodigy. We found that both procedures generate similar CAR T cell products, highly enriched of stem cell memory T cells (T_SCM) and equally effective in counteracting tumor growth in xenograft mouse models. Most importantly, the optimized protocol was able to expand CAR T_SCM from B-cell acute lymphoblastic leukemia (B-ALL) patients, which in origin were highly enriched of late-memory and exhausted T cells. Notably, CAR T cells derived from B-ALL patients proved to be as efficient as healthy donor-derived CAR T cells in mediating profound and prolonged anti-tumor responses in xenograft mouse models. On the contrary, the protocol failed to expand fully functional CAR T_SCM from patients with pancreatic ductal adenocarcinoma, suggesting that patient-specific factors may profoundly affect intrinsic T cell quality. Finally, by retrospective analysis of in vivo data, we observed that the proportion of T_SCM in the final CAR T cell product positively correlated with in vivo expansion, which in turn proved to be crucial for achieving long-term remissions. Collectively, our data indicate that next-generation manufacturing protocols can overcome initial T cell defects, resulting in T_SCM-enriched CAR T cell products qualitatively equivalent to the ones generated from healthy donors. However, this positive effect may be decreased in specific conditions, for which the development of further improved protocols and novel strategies might be highly beneficial.

Feasibility of leukapheresis for CAR T-cell production in heavily pre-treated pediatric patients

BACKGROUND

Autologous CD19 chimeric-antigen receptor (CAR) T-cells are an effective salvage therapy for patients with relapsed or refractory B cell malignancies. The essential first step in the production is the collection of mature lymphocytes through leukapheresis. It is a challenging procedure given the fact patients are heavily pretreated and the special considerations of pediatric apheresis.

METHODS

We analyzed the data of leukapheresis outcome for CAR T production in a phase 1b/2 clinical trial enrolling 34 children, adolescents and young adults with relapsed or refractory B-cell malignancies.

RESULTS

All patients underwent a single leukapheresis. Given a short production time for CAR T-cells, most patients received bridging therapy prior to apheresis. Leukapheresis was performed using peripheral venous access in the majority (82%) of patients, and the remainder required arterial line or central venous access. T-cell collection efficiency (CE) was variable with a median of 18%. No apheresis-related adverse events were noted, and all procedures were successful but two: one resulting in lower than target dose (1 × 10⁶ CAR + cells/kg) and the other in failure of CAR T-cell production.

CONCLUSIONS

Collection of sufficient T-cells in heavily pretreated pediatric patients via a single apheresis procedure is feasible even with relatively low T-cell CE.

Development of CAR-T cell therapy for B-ALL using a point-of-care approach

Recently approved by the FDA and European Medicines Agency, CAR-T cell therapy is a new treatment option for B-cell malignancies. Currently, CAR-T cells are manufactured in centralized facilities and face bottlenecks like complex scaling up, high costs, and logistic operations. These difficulties are mainly related to the use of viral vectors and the requirement to expand CAR-T cells to reach the therapeutic dose. In this paper, by using Sleeping Beauty-mediated genetic modification delivered by electroporation, we show that CAR-T cells can be generated and used without the need for ex vivo activation and expansion, consistent with a point-of-care (POC) approach. Our results show that minimally manipulated CAR-T cells are effective in vivo against RS4;11 leukemia cells engrafted in NSG mice even when inoculated after only 4 h of gene transfer. In an effort to better characterize the infused CAR-T cells, we show that 19BBz T lymphocytes infused after 24 h of electroporation (where CAR expression is already detectable) can improve the overall survival and reduce tumor burden in organs of mice engrafted with RS4;11 or Nalm-6 B cell leukemia. A side-by-side comparison of POC approach with a conventional 8-day expansion protocol using Transact beads demonstrated that both approaches have equivalent antitumor activity in vivo. Our data suggest that POC approach is a viable alternative for the generation and use of CAR-T cells, overcoming the limitations of current manufacturing protocols. Its use has the potential to expand CAR immunotherapy to a higher number of patients, especially in the context of low-income countries.

Improving CAR T cell therapy by optimizing critical quality attributes

Whether as a cure or bridge to transplant, chimeric antigen receptor (CAR)-T cell therapies have shown dramatic outcomes for the treatment of hematologic malignancies, and particularly relapsed/refractory B cell leukemia and lymphoma. However, these therapies are not effective for all patients, and are not without toxicities. The challenge now is to optimize these products and their manufacture. The manufacturing process is complex and subject to numerous variabilities at each step. These variabilities can affect the critical quality attributes of the final product, and this can ultimately impact clinical outcomes. This review will focus on optimizing the manufacturing variables that can impact the safety, purity, potency, consistency and durability of CAR-T cells.

Mobilization and collection of cells in the hematologic compartment for cellular therapies: Stem cell collection with G-CSF/plerixafor, collecting lymphocytes/monocytes

An essential and influential first step in all cellular therapies is collecting donor or patient cells. In hematopoietic progenitor cell transplantation, autologous or allogeneic hematopoietic progenitor cells (HPCs) are collected from either the bone marrow or the peripheral blood. Peripheral blood collection by apheresis requires mobilization with chemotherapy, granulocyte colony stimulating factor (G-CSF), plerixafor, or a combination. The modalities of mobilization and collection each carry a unique set of risks and benefits for both the donor and the recipient. In other types of cell therapy, most notably chimeric antigen receptor T cells, lymphocytes or monocytes are collected from the peripheral blood. The risks of collecting these cells by apheresis are similar to HPCs, but less is known about the composition, timing and qualitative cell characteristics which contribute to an optimal collection. Here, we review the mobilization and collection of HPCs and the collection of lymphocytes and monocytes. Donor safety is of primary importance when collecting material for any type of cell therapy. Every aspect of mobilization and collection can be studied and potentially optimized to improve patient outcomes.