All content on this site is intended for healthcare professionals only. By acknowledging this message and accessing the information on this website you are confirming that you are a Healthcare Professional. If you are a patient or carer, please visit the International Myeloma Foundation or HealthTree for Multiple Myeloma.

The Multiple Myeloma Hub uses cookies on this website. They help us give you the best online experience. By continuing to use our website without changing your cookie settings, you agree to our use of cookies in accordance with our updated Cookie Policy

An expert panel hosted by

The Lymphoma Hub logo and the Multiple Myeloma Hub logo

Sequencing immune-based therapies in B-cell malignancies

with Ulric Jäger, Sagar Lonial, and Krina Patel

Saturday, June 15 | 18:00-19:30 CEST

Register now

This independent education activity is sponsored by Bristol Myers Squibb. All content is developed independently by the faculty. Funders are allowed no direct influence on the content of this activity.


The Multiple Myeloma Hub website uses a third-party service provided by Google that dynamically translates web content. Translations are machine generated, so may not be an exact or complete translation, and the Multiple Myeloma Hub cannot guarantee the accuracy of translated content. The Multiple Myeloma Hub and its employees will not be liable for any direct, indirect, or consequential damages (even if foreseeable) resulting from use of the Google Translate feature. For further support with Google Translate, visit Google Translate Help.

Steering CommitteeAbout UsNewsletterContact
You're logged in! Click here any time to manage your account or log out.
You're logged in! Click here any time to manage your account or log out.

Lymphodepletion optimization for CAR T-cell therapy

Oct 17, 2020

Bookmark this article

Chimeric antigen receptor (CAR) T-cell therapy is becoming more common in the treatment of both hematological and solid tumors. Prior to infusion, lymphodepletion is frequently performed, however, no standardized protocol exists for this procedure. During the eighth annual meeting of the Society of Hematologic Oncology (SOHO), Elizabeth Budde presented how this process can be optimized to aid persistence and efficacy of infused CAR T cells.1

Why use lymphodepletion?

Lymphodepletion leads to lymphopenia, affecting T, B, and NK cells, and it has multiple positive effects prior to CAR T-cell therapy:

  • Debulking of the tumor
  • Alteration of tumor phenotype
    • Decreased production of certain metabolites
    • Change in expression of costimulatory molecules
  • Modified tumor microenvironment
    • Reduced regulatory T-cells and damage to vascular endothelial cells make the environment more hospitable to CAR T cells
  • Removal of cytokine sinks
    • Greater availability of interleukin (IL)-2, IL-7, and IL-15
  • Suppression of host immune system
    • Decreased immunogenicity and increased persistence of infused CAR T cells

Negatives effects of lymphodepletion include the following:

  • Neutropenia, anemia, thrombocytopenia, and immunosuppression, leading to a greater risk of infection
  • Specific toxicities associated with lymphodepletion agents
    • Fludarabine (Flu): fevers and neurotoxicity
    • Cyclophosphamide (Cy): hemorrhagic cystitis, pericarditis, and neurotoxicity
    • Use of these agents may increase the risk of developing secondary malignancies

What is the ideal lymphodepletion regimen?

Cy/Flu combination was compared with Cy alone. Lymphodepletion with the combined treatment of Cy/Flu increased CD19 CAR T-cell expansion and resulted in greater persistence both in CD4 and CD8 cells. In addition, following a second infusion of CAR T cells, Cy/Flu treatment resulted in a second peak with significant cell expansion and longer persistence. On the contrary, when using Cy treatment alone, the second round of CAR T-cell treatment resulted in no cell persistence extension, potentially due to immune rejection.

A study published in 2018 by C. A. Ramos, et al.,2 reported that patients with B-cell lymphoma treated with CAR T-cell therapy who did not undergo pre-infusion lymphodepletion therapy had a very poor cell expansion. The increased CAR T-cell expansion and persistence with the Cy/Flu regimen have also been associated with improved clinical outcomes, and the degree of persistence is related to the level of improvement.

How can the lymphodepletion regimen be optimized?

While high-dose lymphodepletion can be useful in some cases, it is important to keep in mind the associated toxicity of the agents being used. Another option explored is to change the agent rather than increasing the dose. A recent study by C. A. Ramos, et al.,3 compared the safety of bendamustine alone, bendamustine + Flu, and Cy/Flu before the infusion of CD30 CAR T-cell therapy in patients with Hodgkin lymphoma.

The lymphodepletion dosages were as follows:

  • Bendamustine 90 mg/m2/day for 2 days
  • Bendamustine 70 mg/m2/day + Flu 30 mg/m2/day for 3 days
  • Cy 500 mg/m2/day + Flu 30 mg/m2/day for 3 days

In this study, lymphodepletion with bendamustine + Flu resulted in longer persistence of CAR T cells compared with Cy/Flu. In addition, bendamustine + Flu was shown to significantly increase the level of circulating IL-15 and IL-17 compared with bendamustine alone (p < 0.05). These beneficial anti-tumor effects of bendamustine + Flu can be seen in the impact on survival outcomes since it significantly increased progression-free survival compared with bendamustine alone or Cy/Flu (p = 0.0004). The study concluded that Flu is essential as part of the lymphodepletion regimen. Read the complete report here.

Table 1. Alternative methods for optimization of lymphodepletion beyond bendamustine in patients with lymphoma1

Axi-cel, axicabtagene ciloleucel; CAR, chimeric antigen receptor.


Study example


Addition a checkpoint inhibitor


Increase CAR T-cell activity and persistence

Addition of rituximab

ZUMA-14 (axi-cel)

Increased anti-lymphoma effect and CAR T-cell persistence

Addition of anti-CD52 monoclonal antibody

ALPHA (Allo-501)

Increased anti-lymphoma effect and CAR T-cell persistence

The ALPHA study (NCT03939026), as mentioned in Table 1, used Allo-647, a monoclonal antibody against CD52, for the lymphodepletion of patients (N = 22) with relapsed/refractory diffuse large B-cell lymphoma. Allo-647 was administered alongside Flu/Cy in 3 different treatment arms:

  • Low dose Allo-647 (13 mg/day) + Cy (300 mg/m2/day) for 3 days + Flu (30 mg/m2/day)
  • Concomitant Allo-647 (30 mg/day) + Cy/Flu for 3 days
  • Staggered Allo-647 (30 mg/day) + Cy/Flu for 3 days

The preliminary report was with a median follow-up time of 3.8 months (range, 0.7−6.1 months). Although the number of patients evaluated was small, the higher dose of Allo-647 was associated with more significant suppression of endogenous T cells and a higher complete response rate (50% versus 27%) than the lower dose. Read the full report here.


Lymphodepletion before CAR T-cell therapy effectively prolongs the persistence of infused cells and increases the effectiveness of the treatment of tumors. Fludarabine is a critical component of a lymphodepletion regimen and greatly contributes to the efficacy of the procedure. While Flu/Cy is effective in multiple tumor types, there is still scope for optimization for specific cancers, ensuring that the potential toxicities of the agents used are balanced with the benefits of treatment.

  1. Budde E. Optimizing lymphodepletion prior to CAR T cell therapy. Eight annual meeting of SOHO; Sept 11, 2020; Virtual.
  2. Ramos CA, Rouce R, Robertson CS, et al. In vivo fate and activity of second- versus third-generation CD19-specific CAR-T cells in B cell non-Hodgkin’s lymphomas. Mol Therap. 2018;26(2):P2727-P2737. DOI: 1016/j.ymthe.2018.09.009
  3. Ramos CA, Grover NS, Beaven AW, et al. Anti-CD30 CAR-T cell therapy in relapsed and refractory hodgkin lymphoma. J Clin Oncol. 2020; JCO2001342. DOI: 1200/JCO.20.01342


Subscribe to get the best content related to multiple myeloma delivered to your inbox