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Introduction: Multiple myeloma (MM) is an incurable bone marrow (BM)-based cancer involving clonal plasma cells. Most patients show elevated levels of serum monoclonal protein (sMP) and kappa or lambda serum free light chains (sFLCs) at diagnosis. However, around 1-2% of patients, termed nonsecretory, do not produce these biomarkers. As the disease progresses, more patients may become unevaluable using conventional markers, requiring invasive and expensive procedures like BM biopsies and positron emission tomography-computed tomography (PET-CT) scans for assessment and highlighting the need for alternative methods to monitor disease progression. Case Presentation: We present a case report of an MM patient who developed nonsecretory disease during his second line of treatment when he complained of new rib pain; progressive disease was then confirmed on a PET-CT scan. The patient showed an increase in his serum B-cell maturation antigen (sBCMA) levels whereas his conventional myeloma markers did not detect disease activity (sMP remained undetectable and involved sFLC level was normal). After starting a new treatment regimen, his rib pain disappeared, PET-CT scan improved, and sBCMA levels decreased. Upon relapse, he developed increased rib pain with a rising sBCMA level; his conventional myeloma markers did not detect disease activity. After changing to a new regimen, his rib pain improved, and this was accompanied by a decrease in his sBCMA levels. Conclusion: Thus, this case exemplifies the potential for sBCMA to provide a non-invasive method for monitoring MM patients who develop nonsecretory disease.
RESUMEN
OBJECTIVES: Isatuximab is approved for treatment of relapsed/refractory multiple myeloma (RRMM) with dexamethasone and carfilzomib or pomalidomide. Patients receiving these three-drug regimens have exhibited more Grade ≥ 3 adverse events (AEs) compared to the two-drug class combination of isatuximab and steroids alone. Thus, this single-center retrospective study investigated the efficacy of isatuximab with dexamethasone and methylprednisolone (ISAdm) for RRMM patients showing only biochemical progression (BP) of their disease. METHODS: Twenty-four RRMM patients exhibiting only BP were administered isatuximab at 10 mg/kg with dexamethasone once weekly for cycle 1 of a 28-day cycle, followed by every other week for each cycle thereafter. Starting in cycle 2, oral methylprednisolone was added every other day stopping 48 h before and starting 48 h after each dexamethasone infusion. RESULTS: Overall response rate and clinical benefit rate were 63% and 79%, respectively. Progression free survival was 12.9 months. There were only 5 AEs of Grade ≥ 3 which included lymphocytopenia (13%), leukopenia (4%), and neutropenia (4%). No Grade ≥ 3 AE related to respiratory infection, anemia, or thrombocytopenia were reported. CONCLUSION: This study shows that the two-drug class combination of ISAdm is an effective and well tolerated treatment option for RRMM patients exhibiting only BP.