Progression-Free and Overall Survival After KRd Consolidation in FDG PET/CT Positive Patients After ASCT: A Phase II Study (CONPET)

Jakob Nordberg Nørgaard; Niels Abildgaard; Anna Lysén; Galina Tsykunova; Annette Juul Vangsted; Cristina João; Nora Remen; Liv Osnes; Caroline Stokke; James P Connelly; Mona-Elisabeth R Revheim; Fredrik Schjesvold

doi:10.1016/j.clml.2025.10.020

Progression-Free and Overall Survival After KRd Consolidation in FDG PET/CT Positive Patients After ASCT: A Phase II Study (CONPET)

Clin Lymphoma Myeloma Leuk. 2025 Nov 2:S2152-2650(25)04263-6. doi: 10.1016/j.clml.2025.10.020. Online ahead of print.

Authors

Affiliations

¹ Oslo Myeloma Center, Department of Hematology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway; KG Jebsen Center for B cell malignancies, University of Oslo, Oslo, Norway. Electronic address: jaknoe@ous-hf.no.
² Department of Hematology, Odense University Hospital, Odense, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
³ Oslo Myeloma Center, Department of Hematology, Oslo University Hospital, Oslo, Norway; KG Jebsen Center for B cell malignancies, University of Oslo, Oslo, Norway.
⁴ Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Division of Hematology, Haukeland University Hospital, Bergen, Norway.
⁵ Department of Hematology, Rigshospitalet, Copenhagen, Denmark.
⁶ Department of Hematology, Champalimaud Centre for the Unknown, Lisboa, Portugal; Nova Medical School, Universidade Nova de Lisboa, Portugal.
⁷ Oslo Myeloma Center, Department of Hematology, Oslo University Hospital, Oslo, Norway.
⁸ Department of Immunology, Oslo University Hospital, Oslo, Norway.
⁹ Division for Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
¹⁰ Institute of Clinical Medicine, University of Oslo, Oslo, Norway; The Intervention Center, Oslo University Hospital, Oslo, Norway.

PMID: 41314938
DOI: 10.1016/j.clml.2025.10.020

Abstract

Background: In multiple myeloma, ¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) positivity after first-line autologous stem cell transplantation (ASCT) is associated with reduced progression-free survival (PFS) and overall survival (OS). Intensified treatment may abrogate the adverse effects of a positive PET after ASCT, but this treatment strategy has not been evaluated in prospective clinical trials.

Patients and methods: In this phase II clinical study, patients who were in at least very good partial response (VGPR) after ASCT and had a positive PET received four cycles of KRd treatment. These patients were compared with patients in at least VGPR after ASCT that were PET negative and received standard post-ASCT treatment. Bone-marrow based minimal residual disease (MRD) assessment at a sensitivity of 10^-5 was performed before and after treatment in the PET positive patients.

Results: After a median follow-up of 53 months, PFS was similar between PET positive patients who received KRd and PET negative patients who received standard of care (median 65.3 months vs. median 51.3 months, P = .610). Median OS was not reached in either group. MRD status after KRd treatment was significantly associated with PFS and OS, and patients who were both MRD and PET positive after KRd treatment had poor prognosis.

Conclusion: Long-term outcomes were similar between PET positive patients who received KRd consolidation therapy and PET negative patients who received standard post-ASCT therapy. Newer treatment strategies are needed for patients who are both PET/CT and MRD positive after intensified consolidation therapy.

Keywords: Autologous stem cell transplantation; Clinical trial; Imaging; Long-term outcomes; Multiple myeloma.