Journal Article DKFZ-2025-01703

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png
Boosting CAR T-Cell Efficacy by Blocking Proteasomal Degradation of Membrane Antigens.

 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;

2026
American Society of Hematology Washington, DC

Blood 147(5), 534-546 () [10.1182/blood.2024027616]
 GO

This record in other databases:  

Please use a persistent id in citations: doi:

Abstract: Chimeric antigen receptor (CAR) T cells exhibit high response rates in B cell malignancies, but most patients eventually relapse. A key mechanism of treatment failure is the loss or downregulation of tumor antigen expression, yet strategies to modulate cell surface levels of CAR T cell targets remain largely unexplored. Here we identify B cell maturation antigen (BCMA), a central CAR T cell target in multiple myeloma (MM), as a highly short-lived protein that undergoes K48-linked polyubiquitylation at the plasma membrane, leading to its p97-dependent degradation via the ubiquitin-proteasome system (UPS). This previously unprecedented mechanism of plasma membrane protein regulation enables significant enhancement of BCMA expression via proteasome inhibitors (PI). The clinically approved PI carfilzomib (CFZ) significantly enhances the efficacy of BCMA-directed CAR T cells against both PI-sensitive and refractory MM cells in vitro and in vivo. Notably, treatment of ten patients with CFZ under the compassionate use CarCAR protocol - after relapse following BCMA CAR T cell therapy - resulted in increased BCMA expression in all patients. However, clinical responses were observed only in those with residual and/or expanding CAR T cells, suggesting restored CAR T cell function. These findings provide a rationale for the use of CFZ treatment in relapsed or refractory MM following BCMA CAR T therapy, advocate for future trials combining CFZ with BCMA CAR T cells and provide a framework for exploring UPS-dependent degradation of other immunotherapy antigens.

Classification:

Note: 2026 Jan 29;147(5):534-546

Contributing Institute(s):
  1. DKTK Koordinierungsstelle München (MU01)
Research Program(s):
  1. 899 - ohne Topic (POF4-899) (POF4-899)

Appears in the scientific report 2025
Database coverage:
Medline ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; Current Contents - Life Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 20 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection
Click to display QR Code for this record

The record appears in these collections:
Document types > Articles > Journal Article
Public records
Publications database

 Record created 2025-08-15, last modified 2026-02-02



Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)