IMS 2025 | High non-clonal plasma cell fraction at diagnosis linked to better outcomes in myeloma

Risk stratification in multiple myeloma is largely driven by the cytogenetic features of plasma cells. There is emerging evidence to suggest that the non-clonal fraction of plasma cells in the bone marrow may play an important role in prognostication. We know that in smoldering myeloma the percentage of aberrant plasma cells is associated with a risk of progression to active myeloma and we are seeing evidence of the same in our study. We looked at over 800 newly diagnosed multiple myeloma patients and we did multiparametric flow cytometry on the bone marrow biopsies at diagnosis. Using a custom gating panel, we identified that patients that have at least 5% or more non-clonal plasma cells account for about 15% of the cohort. These patients had a markedly improved overall survival with a six-year overall survival rate of 70% compared to 56% for patients with a low non-clonal plasma cell fraction, giving us a hazard ratio of 0.64. We also note that patients with an elevated non-clonal plasma cell fraction have much lower rates of severe immune paresis, about 27%, compared to more than 60% in patients who have a low proportion of non-clonal plasma cells. All this also correlates very well with the PFS difference as well, where the hazard ratio of around 0.7 is seen in patients that have an elevated non-clonal plasma cell fraction. An elevated non-clonal plasma cell fraction may represent a marker of the immune status in patients, which adds another dimension to the risk stratification in multiple myeloma.

This transcript is AI-generated. While we strive for accuracy, please verify this copy with the video.