PDF icon Download PDF
Open Access
CC BY 4.0 · Indian J Med Paediatr Oncol
DOI: 10.1055/s-0045-1808240
Original Article

Efficiency of Inotuzumab Ozogamicin in Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia in Relation to CD22 Expression

Thulasi Raman Ramalingam 
1   Department of Haematology, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Elamperiyar Subramani
1   Department of Haematology, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Bharaneedharan Marimuthu
1   Department of Haematology, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Harsha N. Rasheed
1   Department of Haematology, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Ramya Uppuluri
2   Department of Pediatric Haematology, Oncology, Blood and Marrow Transplantation, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Lakshman Vaidhyanathan
1   Department of Haematology, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Jose Easow
3   Department of Medical Oncology, Blood and Marrow Transplantation, Apollo Cancer Centre, Chennai, Tamil Nadu, India
,
Revathi Raj
2   Department of Pediatric Haematology, Oncology, Blood and Marrow Transplantation, Apollo Cancer Centre, Chennai, Tamil Nadu, India
› Author Affiliations
Funding None.
› Further Information
Also available ateRef
  Permissions and Reprints
Preview

Abstract

Introduction

B-cell acute lymphoblastic leukemia (B-ALL) is characterized by the proliferation of immature B lymphoid blasts causing bone marrow failure. Inotuzumab ozogamicin (InO), an anti-CD22 targeted therapy, is an effective treatment option for relapsed/refractory (R/R) B-ALL.

Objectives

The primary aim was to determine the efficiency of InO in relation to CD22 expression in leukemic cells. The other objectives were to study the efficiency of InO in different cytogenetically defined B-ALL groups and to examine the post-InO CD22 modulation in residual leukemic cells.

Materials and Methods

This retrospective study was done in a cohort of R/R B-ALL patients treated with InO. The CD22 expression was studied by normalized median fluorescent intensity (nMFI), percentage of leukemic blasts positive for CD22, and also the pattern of CD22 expression with flow cytometry.

Results

A total of 21 R/R B-ALL cases treated with InO were enrolled in the study. Measurable residual disease (MRD) negativity was achieved in 17 cases with InO. The MRD-negative group showed a diverse CD22 expression patterns. We found that InO was effective in leukemic cells weakly expressing CD22. No considerable difference in CD22 nMFI and its percentage was noted among the post-InO MRD positive and negative cohorts. MRD negativity was achieved in all Philadelphia chromosome-positive (Ph + ) R/R B-ALL cases. All four post-InO MRD+ cases showed downmodulation of CD22.

Conclusion

InO is effective in treating R/R B-ALL, including in cases with weak CD22 expression, and can serve as a bridge to hematopoietic stem cell transplant.

Keywords

inotuzumab - relapsed B-ALL - CD22 - flow cytometry - measurable residual disease

Data Availability Statement

Data will be available from the corresponding author upon request.


Authors' Contributions

Conception and design: T.R.R. Provision of study materials or patients: All authors. Collection and assembly of data: T.R.R., E.S., and B.M. Data analysis and interpretation: T.R.R. Manuscript writing: T.R.R. Final approval of manuscript: All authors.


Patient Consent

Waiver of consent document was approved by the Institutional Ethics Committee.




Publication History

Article published online:
30 April 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India