Objective: In this study, we aimed to obtain real-life data on the use of antimyeloma agents, which significantly increase overall survival (OS) in multiple myeloma (MM) patients, in primary plasma cell leukemia (pPCL) patients with a poor prognosis.
Materials and methods: Data from 53 patients who were diagnosed with pPCL between 2011-2020 and who used at least one proteasome inhibitor (PI) and/or immunomodulatory (IMID) agent were analyzed retrospectively. Depending on the year of pPCL diagnosis, 20% leukocytes or ≥2×109/L plasma cells in the peripheral blood were used.
Results: The median age of the patients was 58 years, and 23 (43.4%) patients were over 65 years of age. For first-line treatment, PI or IMID alone was used in 31 (58.5%) patients, and PI and IMID were used simultaneously in 15 (28.3%) patients. Additionally, 21 (39.6%) patients received transplantation, and 13 (24.5%) patients received maintenance treatment. The median progression-free survival was 4 (1-42) months. When patients whose primary disease was refractory to first-line therapy were excluded, the duration of treatment was 6.5 months. The median OS was 15 months, with a median follow-up of 15 months. Only 7 (13.2%) of the patients were alive at the last follow-up visit. Those with higher beta-2 microglobulin levels and ISS stage 3 and nontransplant patients receiving first-line treatment had shorter OS (p=0.005, p=0.02 and p=0.008, respectively). Otherwise, the concomitant use of PIs and IMIDs, the addition of chemotherapy to induction therapy, and the response to induction therapy or maintenance therapy did not affect OS.
Conclusion: In our study, as in previous similar studies, we could not see the increased survival trend in pPCL which is observed in MM. New studies are needed for pPCL patients, which is likely to increase with the new diagnostic criteria, based on current agents and information in MM.
Keywords: Antimyeloma agents; Hematopoietic stem cell transplantation; Immunomodulatory agents; Primary plasma cell leukemia; Proteasome inhibitors.