Optimization and validation of the international metabolic prognostic index for CD19 CAR-T in large B-cell lymphoma
While CD19-directed CAR T-cell therapy represents a transformative immunotherapy for relapsed/refractory large B-cell lymphoma (r/r LBCL), more than 50% of patients ultimately progress or relapse. Recently, the International Metabolic Prognostic Index (IMPI) - incorporating age, stage, and metabolic tumor volume (MTV) - was shown to improve prognostication for LBCL frontline treatment. Here, we examine its utility to predict toxicity and survival in CAR-T recipients. This multicenter observational study spanning six international sites included 504 patients with available <sup>18</sup>FDG-PET/CT imaging at last response assessment prior to lymphodepletion. Optimal CAR-adapted MTV thresholds were identified in a development cohort (n = 256) and incorporated into a CAR-T-specific IMPI ("CAR-IMPI"). The prognostic performance of CAR-IMPI was validated in an independent cohort (n = 248). CAR-IMPI risk categories, defined by the median (1.35) and terciles (1.07, 1.58), demonstrated significant discrimination for progression-free survival (PFS; p < 0.0001) and overall survival (OS; p < 0.0001) in both cohorts. Multivariate Cox regression confirmed CAR-IMPI as an independent predictor of survival, accounting for pre-lymphodepletion LDH and CRP, performance status, treatment center, and CAR-T product. Patients in the CAR-IMPI high-risk category experienced increased severity of CRS and ICANS, and higher rates of intensive care unit (ICU) admissions. In an exploratory analysis, combining CAR-IMPI with established indices of high-risk systemic inflammation (CAR-HEMATOTOX, InflaMix) further enhanced survival stratification. The CAR-IMPI may provide a potent and validated PET-based tool for risk stratification of clinical outcomes in patients with r/r LBCL receiving CD19 CAR-T therapy. Our data highlight the utility of combining clinical and radiological modalities, with implications for patient selection and the anticipated level-of-care for toxicity management.
Authors
- Marion Subklewe (ORCID: https://orcid.org/0000-0001-9154-9469)
- Michael David Jain (ORCID: https://orcid.org/0000-0002-7789-1257)
- Heiko M. Schöder (ORCID: https://orcid.org/0000-0002-5170-4185)
- Frederick Lundry Locke (ORCID: https://orcid.org/0000-0001-9063-6691)
- Gunjan L. Shah (ORCID: https://orcid.org/0000-0002-9977-0456)
- Magdalena Corona (ORCID: https://orcid.org/0000-0002-6553-0171)
- Roni Shouval (ORCID: https://orcid.org/0000-0001-9827-8032)
- Fabian Müller (ORCID: https://orcid.org/0000-0001-5487-5839)
- Pere Barba (ORCID: https://orcid.org/0000-0001-7076-7969)
- Akshay Bedmutha (ORCID: https://orcid.org/0000-0001-5683-4918)
- Gloria Iacoboni (ORCID: https://orcid.org/0000-0003-0805-9288)
- Veit Bücklein (ORCID: https://orcid.org/0000-0001-7391-7280)
- Michael Winkelmann (ORCID: https://orcid.org/0000-0003-4655-7341)
- Michael Scordo (ORCID: https://orcid.org/0000-0002-9484-0240)
- Doris Leithner (ORCID: https://orcid.org/0000-0002-0163-3964)
- Maria Lia Palomba (ORCID: https://orcid.org/0000-0001-5099-9156)
- Kai Rejeski (ORCID: https://orcid.org/0000-0003-3905-0251)
- Gabriel T. Sheikh (ORCID: https://orcid.org/0000-0002-7026-9203)
- Khushali Jhaveri (ORCID: https://orcid.org/0000-0002-0232-3896)
- Alexander P. Boardman (ORCID: https://orcid.org/0000-0001-7169-9275)
- Sandeep S. Raj (ORCID: https://orcid.org/0000-0003-4629-0528)
- Leo Hansmann (ORCID: https://orcid.org/0000-0003-3790-0128)
- Wolfgang G. Kunz (ORCID: https://orcid.org/0000-0002-5021-1952)
- Alejandro Luna (ORCID: https://orcid.org/0000-0003-2201-3091)
- Miguel‐Angel Perales (ORCID: https://orcid.org/0000-0002-5910-4571)
- Gilles Salles (ORCID: https://orcid.org/0000-0002-9541-8666)
- Tobias Tix
- Jae H. Park (ORCID: https://orcid.org/0000-0002-2903-5130)
- Erin Dean (ORCID: https://orcid.org/0000-0003-3153-223X)
- Turab Mohammad
Institutions
- Universitat Autònoma de Barcelona (ES)
- Siemens (Germany) (DE)
- Memorial Sloan Kettering Cancer Center (US)
- German Cancer Research Center (DE)
- Friedrich-Alexander-Universität Erlangen-Nürnberg (DE)
- Cornell University (US)
- Heidelberg University (DE)
- University of South Florida (US)
- University Hospital Heidelberg (DE)
- LMU Klinikum (DE)
- Moffitt Cancer Center (US)
- University Hospital Regensburg (DE)
- University of Florida (US)
- Universitätsklinikum Erlangen (DE)
- German Center for Infection Research (DE)
- Indiana University Bloomington (US)
- Vall d'Hebron Hospital Universitari (ES)
- Comprehensive Cancer Center Erlangen (DE)
- Vall d'Hebron Institute of Oncology (ES)
- Ludwig-Maximilians-Universität München (DE)
Publication Details
- Journal
- Blood Cancer Journal
- Published
- 2025-08-26
- DOI
- https://doi.org/10.1038/s41408-025-01338-1
- Citations
- 4
- Primary Topic
- CAR-T cell therapy research
- Type
- article
- Field-Weighted Citation Impact
- 4.18
Funders
- Memorial Sloan-Kettering Cancer Center
- National Institutes of Health
- National Cancer Institute