Journal: Blood
This phase 3 GEM12 trial evaluated long-term outcomes of autologous stem cell transplantation (ASCT) conditioning using busulfan plus melphalan (BUMEL) versus melphalan alone (MEL200) in newly diagnosed multiple myeloma (NDMM) patients. All patients received intensified bortezomib, lenalidomide, and dexamethasone (VRD) induction and consolidation.
Among 458 randomized patients:
- Minimal residual disease (MRD)-negative rate (10⁻⁶): Higher with BUMEL (68%) compared to MEL200 (58%, P = .035)
- Median progression-free survival (PFS): 89 months for BUMEL vs. 73.1 months for MEL200 (not statistically significant overall, P = .3)
BUMEL showed particular benefit in:
- Patients with more advanced disease (ISS stages II/III)
- Certain high-risk genetic features (t(14;16), del(1p))
No new safety concerns were observed after a median follow-up of 8.4 years.
These results highlight one of the longest reported PFS durations in NDMM, favoring BUMEL conditioning in higher-risk patient subsets.