Loss of CD20 expression as a mechanism of resistance to mosunetuzumab in relapsed/refractory B-cell lymphomas

© 2024 American Society of Hematology. Published by Elsevier Inc. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved..

ABSTRACT: CD20 is an established therapeutic target in B-cell malignancies. The CD20 × CD3 bispecific antibody mosunetuzumab has significant efficacy in B-cell non-Hodgkin lymphomas (NHLs). Because target antigen loss is a recognized mechanism of resistance, we evaluated CD20 expression relative to clinical response in patients with relapsed and/or refractory NHL in the phase 1/2 GO29781 trial investigating mosunetuzumab monotherapy. CD20 was studied using immunohistochemistry (IHC), RNA sequencing, and whole-exome sequencing performed centrally in biopsy specimens collected before treatment at predose, during treatment, or upon progression. Before treatment, most patients exhibited a high proportion of tumor cells expressing CD20; however, in 16 of 293 patients (5.5%) the proportion was <10%. Analyses of paired biopsy specimens from patients on treatment revealed that CD20 levels were maintained in 29 of 30 patients (97%) vs at progression, where CD20 loss was observed in 11 of 32 patients (34%). Reduced transcription or acquisition of truncating mutations explained most but not all cases of CD20 loss. In vitro modeling confirmed the effects of CD20 variants identified in clinical samples on reduction of CD20 expression and missense mutations in the extracellular domain that could block mosunetuzumab binding. This study expands the knowledge about the occurrence of target antigen loss after anti-CD20 therapeutics to include CD20-targeting bispecific antibodies and elucidates mechanisms of reduced CD20 expression at disease progression that may be generalizable to other anti-CD20 targeting agents. These results also confirm the utility of readily available IHC staining for CD20 as a tool to inform clinical decisions. This trial was registered at www.ClinicalTrials.gov as #NCT02500407.

Errataetall:

CommentIn: Blood. 2024 Feb 29;143(9):744-746. - PMID 38421818

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:143

Enthalten in:

Blood - 143(2024), 9 vom: 29. Feb., Seite 822-832

Sprache:

Englisch

Beteiligte Personen:

Schuster, Stephen J [VerfasserIn]
Huw, Ling-Yuh [VerfasserIn]
Bolen, Christopher R [VerfasserIn]
Maximov, Victor [VerfasserIn]
Polson, Andrew G [VerfasserIn]
Hatzi, Katerina [VerfasserIn]
Lasater, Elisabeth A [VerfasserIn]
Assouline, Sarit E [VerfasserIn]
Bartlett, Nancy L [VerfasserIn]
Budde, L Elizabeth [VerfasserIn]
Matasar, Matthew J [VerfasserIn]
Koeppen, Hartmut [VerfasserIn]
Piccione, Emily C [VerfasserIn]
Wilson, Deanna [VerfasserIn]
Wei, Michael C [VerfasserIn]
Yin, Shen [VerfasserIn]
Penuel, Elicia [VerfasserIn]

Links:

Volltext

Themen:

Antibodies, Bispecific
Antigens, CD20
Antineoplastic Agents
Journal Article

Anmerkungen:

Date Completed 01.03.2024

Date Revised 24.03.2024

published: Print

ClinicalTrials.gov: NCT02500407

CommentIn: Blood. 2024 Feb 29;143(9):744-746. - PMID 38421818

Citation Status MEDLINE

doi:

10.1182/blood.2023022348

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM365396451