ANALYSIS OF THE EFFECTIVENESS OF BORTEZOMIB-CONTAINING REGIMENS IN PATIENTS WITH MULTIPLE MYELOMA

Introduction. Multiple myeloma is a hematologic malignancy that affects the bone marrow, characterized by the abnormal proliferation of tumor plasma cells. This study aims to assess the effectiveness of a chemotherapy regimen consisting of bortezomib, lenalidomide, and dexamethasone in patients with progressive multiple myeloma, considering negative prognostic factors. Materials and Methods. Group I comprised 23 patients with progressive multiple myeloma who received chemotherapy with bortezomib, lenalidomide, and dexamethasone. The control group (Group II) consisted of 18 healthy individuals. Patients in Group I were examined twice: once before the initiation of treatment and again after completing three courses of chemotherapy. The evaluation included general and biochemical blood analyses, myelogram, immunofixation, and electrophoresis of blood serum and urine proteins, as well as the assessment of monoclonal paraprotein and the level of β2-microglobulin. Treatment response was evaluated according to the criteria set by the International Myeloma Working Group (2016). Results. Among patients receiving chemotherapy as first-line therapy, the overall response rate was 83.33% (15/18), of which a very good partial response was observed in 77.78% (14/18) of patients, a partial response in 5.55% (1/18), and disease progression in 16.67% (3/18) of patients. Specific treatment was associated with a decrease in the level of M-gradient in the blood of patients by 87.6% (p<0.01) and in urine by 96% (p<0.01). A direct correlation was found in Group I between the levels of M-gradient in blood and urine after treatment (r=+0.54; p<0.01 according to Spearman). After three courses of chemotherapy, the levels of total protein and creatinine in the blood serum decreased by 1.2 (p<0.01) and 1.3 times (p<0.05), respectively, compared to the initial examination data. The absence of response in one patient was characterized by an increase in urine M-protein level by 25.7% (0.44 vs. 0.35 g/L) and the presence of plasmacytoma; in the second patient, an increase in blood M-protein content was observed, doubling (11.28 g/L vs. 5.64 g/L). In the third patient, during the second examination, a tumor in the upper part of the sternum on the left with plasmacytic morphology was discovered, which had not been recorded before the start of specific treatment. Conclusion. The presence of plasmacytoma in patients with multiple myeloma may serve as a negative prognostic factor for achieving a response to chemotherapy with bortezomib, lenalidomide, and dexamethasone.