Outcomes of patients with multiple myeloma and 1q gain/amplification receiving autologous hematopoietic stem cell transplant: the MD Anderson cancer center experience.

The prognostic impact of additional copies of chromosome 1q (1q + ) on outcomes of newly-diagnosed multiple myeloma (NDMM) patients undergoing autologous transplantation (autoSCT) is unclear. We conducted a retrospective single-center analysis of NDMM patients with 1q21 gain/amplification (3 or ≥4 copies of 1q, respectively) that received autoSCT between 2008-2018. 213 patients were included (79% 1q gain; 21% 1q amplification). The most commonly used induction regimen was bortezomib, lenalidomide, and dexamethasone (41%). At day100 post-autoSCT and at best post-transplant response, 78% and 87% of patients achieved ≥VGPR, and 38% and 50% achieved MRD-negative ≥VGPR, respectively. Median PFS and OS for the entire cohort were 35.5 months and 81.4 months, respectively. On multivariable assessment for PFS, MRD negative ≥VGPR before autoSCT (HR 0.52, p = 0.013) was associated with superior PFS, whereas 1q amplification was associated with inferior PFS (2.03, p = 0.003). On multivariate analysis for OS, achieving MRD negative ≥VGPR at best post-transplant response was associated with superior survival (0.29, p < 0.001), whereas R-ISS III and concomitant del17p or t(4:14) were associated with inferior survival (6.95, p = 0.030, 2.33, p = 0.023 and 3.00, p = 0.047, respectively). In conclusion, patients with 1q+ NDMM, especially 1q amplification, have inferior survival outcomes compared to standard-risk disease after upfront autoSCT, though outcomes are better than other high-risk cytogenetic abnormalities.