Jerina Hoxha
15.6.25
PET/CT helps identify high-risk myeloma patients after CAR T therapy
A new study supported by the CERTAINTY consortium reveals how PET/CT imaging can detect high-risk relapsed/refractory multiple myeloma (RRMM) patients undergoing BCMA-directed CAR T cell therapy. The findings highlight the value of PET/CT not only at baseline but also in follow-up, offering guidance for risk-adapted treatment strategies.
Background
While PET/CT is routinely used in staging multiple myeloma and detecting extramedullary disease (EMD), its role in CAR T cell therapy has remained unclear. This study analysed 61 RRMM patients treated with cilta-cel or ide-cel, using PET/CT imaging before and after infusion. The scans were assessed using both standard metabolic tumour volume (MTV) metrics and the IMPeTUs classification system.
Key findings
Patients with bone-independent EMD had inferior progression-free survival (PFS) compared to those with other PET/CT-defined lesion groups.
A high MTV (>54.3 mL) was linked to early relapse, but did not affect CAR T expansion or T cell receptor diversity.
PET/CT at day 30 post-infusion revealed that only 37% of patients achieved metabolic complete remission (metCR). Many patients in serological remission still had detectable disease.
Double-negative patients (serological CR and metCR) showed a trend toward better long-term outcomes.
The combination of diffuse bone marrow uptake and EMD (per IMPeTUs criteria) stratified patients into distinct risk groups.
Conclusions
PET/CT provides powerful prognostic information before and after CAR T treatment. It helps flag patients at high risk of early relapse, especially those with high MTV or bone-independent EMD. Follow-up imaging also captures residual disease missed by blood-based assessments. The study supports integrating PET/CT into treatment planning to better personalise and optimise CAR T cell therapy in multiple myeloma.
Access the Publication
Read the full publication in HemaSphere: https://doi.org/10.1002/hem3.70159