PB2169: LENALIDOMIDE, BORTEZOMIB AND DEXAMETHASONE COMBINATION THERAPY IN CONCOMITANT MYELODYSPLASTIC SYNDROME WITH ISOLATED 5Q DELETION AND MULTIPLE MYELOMA

Abstract Topic: 15. Myeloproliferative neoplasms - Biology & Translational Research

Background: De-novo concurrent development of myelodysplastic syndrome (MDS) with isolated del(5q) and multiple myeloma (MM) is rare.

Aims: We aim to report our experience with lenalidomide, bortezomib and dexamethasone therapy in a patient with MDS del(5q) and MM.

Methods: A 73-year-old female presented with persistent neutropenia. Bone marrow analysis showed normocellular marrow with hypolobulated megakaryocytes. There was dysplasia in monopoiesis (CD11b-ht/56het), myelopoiesis (CD34+/13+/33+/117+), 7.7% plasma cell dyscrasia (CD45-/19-/56++/13dim/33dim/117dim) and a karyotype of 46, XX, del(5)(q13q33). FISH for MDS confirmed the deletion of 5q in 16% of the nuclei. Findings of plasma cell dyscrasia raised suspicion for clonal plasma cell disorder. Serum kappa free light chain level was 60.9mg/L, with free kappa/lambda ratio of 7.25. Serum protein electrophoresis was negative and urine immunofixation showed free kappa light chain band. She was asymptomatic with no evidence of end organ manifestations. A concurrent diagnosis of MDS del (5q) and MGUS was established. Over next 2 years, the patient had rising kappa free light chain to 104.9mg/L and worsening neutropenia. A repeat bone marrow showed plasma cells (39%), blasts (2%), and dysplastic changes in both erythroid and megakaryocytic lineages. Skeletal survey showed suspected lytic lesion over L3 vertebrae with no other end organ manifestations. She was treated for standard risk kappa free light chain myeloma and low-risk MDS with isolated del (5q). She tolerated lenalidomide 10 mg daily, bortezomib 1.3 mg/m2 and dexamethasone once weekly of a 28-day cycle, with no treatment related complications. Reassessment of bone marrow following 6 cycles of treatment showed a partial response for MM and complete response for MDS. She was offered autologous stem cell transplant for underlying myeloma which she declined. She completed 1 year of lenalidomide, bortezomib and dexamethasone therapy and is currently on maintenance therapy with lenalidomide with no neutropenia.

Results: This case describes our experience of the standard three-drug induction therapy for this disease entity, which was not associated with significant hematologic toxicities. The role of transplant upfront remains under debate as we consider real-world factors such as treatment burden, long-term toxic effects, patient’s preferences, quality of life and cost burden.

Keywords: Myelodysplastic syndrome, Multiple myeloma