Ferritin Metabolism Reflects Multiple Myeloma Microenvironment and Predicts Patient Outcome.

Multiple myeloma (MM) is a hematologic malignancy with a multistep evolutionary pattern, in which the pro-inflammatory and immunosuppressive microenvironment and genomic instability drive tumor evolution. MM microenvironment is rich in iron, released by pro-inflammatory cells from ferritin macromolecules, which contributes to ROS production and cellular damage. In this study, we showed that ferritin increases from indolent to active gammopathies and that patients with low serum ferritin had longer first line PFS (42.6 vs. 20.7 months and, p = 0.047, respectively) and OS (NR vs. 75.1 months and p = 0.029, respectively). Moreover, ferritin levels correlated with systemic inflammation markers and with the presence of a specific bone marrow cell microenvironment (including increased MM cell infiltration). Finally, we verified by bioinformatic approaches in large transcriptomic and single cell datasets that a gene expression signature associated with ferritin biosynthesis correlated with worse outcome, MM cell proliferation, and specific immune cell profiles. Overall, we provide evidence of the role of ferritin as a predictive/prognostic factor in MM, setting the stage for future translational studies investigating ferritin and iron chelation as new targets for improving MM patient outcome.

Measurable therapeutic antibody in serum as potential predictive factor of response to anti-CD38 therapy in non-IgG-k myeloma patients.

Multiple myeloma (MM) is a hematologic malignancy characterized by abnormal plasma cell proliferation in the bone marrow. Recent advancements in anti-CD38 monoclonal antibody therapies, such as daratumumab and isatuximab, have significantly improved MM patient survival. However, the lack of predictive factors of response to these therapies remains a challenge. Notably, anti-CD38 antibodies can interfere with laboratory tests, complicating response assessment. We conducted a retrospective study to evaluate the association between the appearance of positive IgGk (therapeutic antibody) on immunofixation/immunosubtraction (IF) and clinical parameters in 87 non-IgGk MM patients treated with anti-CD38 therapy. Positive IgGk IF was observed in 42 patients after a median of three treatment courses. Patients with positive IgGk IF had higher rates of complete/very good partial responses (p = 0.03) and improved progression-free survival (median not reached vs. 21.83 months, p < 0.01). High BMI (p = 0.03), higher hemoglobin (p = 0.02), lower CRP (p = 0.04), and lower monoclonal protein levels (p = 0.03) were associated with positive IgGk IF. Our findings suggest that monitoring therapeutic antibody appearance on IF may predict and optimize anti-CD38 therapy in MM. Potential explanations include the impact of patient factors (e.g. BMI) on drug pharmacokinetics, the relationship between antibody levels and immune response, and the influence of tumor biology. Further research is needed to elucidate the underlying mechanisms and clinical utility of this biomarker. Nonetheless, our results highlight the importance of considering therapeutic antibody detection when interpreting laboratory tests and managing MM patients receiving anti-CD38 therapies.

Monoclonal Gammopathies and the Bone Marrow Microenvironment: From Bench to Bedside and Then Back Again.

Multiple myeloma (MM) is an incurable hematologic malignancy characterized by a multistep evolutionary pathway, with an initial phase called monoclonal gammopathy of undetermined significance (MGUS), potentially evolving into the symptomatic disease, often preceded by an intermediate phase called "smoldering" MM (sMM). From a biological point of view, genomic alterations (translocations/deletions/mutations) are already present at the MGUS phase, thus rendering their role in disease evolution questionable. On the other hand, we currently know that changes in the bone marrow microenvironment (TME) could play a key role in MM evolution through a progressive shift towards a pro-inflammatory and immunosuppressive shape, which may drive cancer progression as well as clonal plasma cells migration, proliferation, survival, and drug resistance. Along this line, the major advancement in MM patients' survival has been achieved by the introduction of microenvironment-oriented drugs (including immunomodulatory drugs and monoclonal antibodies). In this review, we summarized the role of the different components of the TME in MM evolution from MGUS as well as potential novel therapeutic targets/opportunities.