Rapamycin Pre-Treatment of CAR T Cells “May Enhance Therapeutic Efficacy Against AML”

News
Article

A recently published article on CAR T cells in patients with acute myeloid leukemia is featured by CancerNetwork's Strategic Alliance Partner ASTCT.

The following was recently published in ASTCT’s Nucleus Plus: Emerging CAR T publication.

Pretreatment of CAR T cells with rapamycin during ex vivo expansion “dramatically enhanced” the cells’ ability to infiltrate bone marrow and promoted the elimination of acute myeloid leukemia (AML) cells, Chinese researchers report in a study published in Clinical Cancer Research in July.

Trials to date have shown only limited efficacy of CAR T-cell therapy in the treatment of AML.

This study, by researchers at the University of Science and Technology of China, suggest that the cause of this limited efficacy may be that CAR-T cells downregulate the expression of CXCR4 during ex vivo expansion, reducing the cells’ in vivo capacity to migrate to bone marrow and weakening their ability to eliminate AML cells there.

“Stimulating T cells with anti-CD3/CD28 antibodies and tonic CAR signaling both strengthen the activation of the mTOR signaling, which causes downregulation of CXCR4,” senior author Haiming Wei and colleagues write. “We found that attenuating mTORC1 activation with rapamycin can overcome this artifact of ex vivo CAR-T cell manipulation, promoting CXCR4 accumulation and thereby increasing the bone marrow migration capacity of CAR-T cells. Ultimately, the rapamycin-pretreated CAR-T cells have an enhanced therapeutic efficacy against AML.”

Rapamycin pretreatment can enhance the ability of both EpCAM CAR-T cells and CD33 CAR-T cells to eliminate bone marrow AML cells, the authors write, suggesting that “this pretreatment strategy is apparently suitable for improving the bone marrow AML elimination capacity of CAR-T cells engineered to target a variety of AML antigens.” They conclude: “Overall, our study illustrates an easy-to-implement strategy that strongly enhances the bone marrow leukemia cell elimination capacity of CAR-T cells and provides a basis for a planned clinical trial using rapamycin pretreated CAR-T cell against AML.”

Reference

Nian Z, Zheng X, Dou Y, et al. Rapamycin pretreatment rescues the bone marrow AML cell elimination capacity of CAR-T cells. Clin Cancer Res. Published online July 7, 2021. doi:10.1158/1078-0432.CCR-21-0452

Recent Videos
Daniel Peters, MD, aims to reduce the toxicity associated with AML treatments while also improving therapeutic outcomes.
Patients with AML will experience different toxicities based on the treatment they receive, whether it is intensive chemotherapy or targeted therapy.
A younger patient with AML who is more fit may be eligible for different treatments than an older patient with chronic medical conditions.
Yale’s COPPER Center aims to address disparities and out-of-pocket costs for patients, thereby improving the delivery of complex cancer treatment.
Non-Hodgkin lymphoma and other indolent forms of disease may require sequencing new treatments for years or decades, said Scott Huntington, MD, MPH, MSc.
Fixed-duration therapy may be more suitable for younger patients, while continuous therapy may benefit those who are older with more comorbidities.
Determining the molecular characteristics of one’s disease may influence the therapy employed in the first line as well as subsequent settings.
A 2-way communication between providers and patients may help facilitate dose modifications to help better manage adverse effects.
Treatment with AML depends on a variety of factors, including stage of treatment, transplant eligibility, and mutational status.
Related Content