Efficacy of ixazomib-lenalidomide-dexamethasone in high-molecular-risk relapsed/refractory multiple myeloma - case series and literature review.

Introduction And Objective: Multiple myeloma (MM) is an incurable condition with variable clinical course. The study included a group of patients with especially poor-prognosis, individuals with relapsed/refractory multiple myeloma (RRMM) and specific cytogenetic disorders. Among the currently used therapies the ixazomib-lenalidomid-dexamethasone (IRd) is considered as a candidate to improve outcomes. The aim of the study was to evaluate the safety and efficacy of IRd regimen in the treatment of patients with RMMM.

Material And Methods: Nine patients aged 52-82 years who received ixazomib in the early access programme, were included in the study. All patients met the criteria for recurrent/relapsed MM and had high (t(4:14), t(14:16), del17p or +1q21) risk aberrations. Previous chemotherapy regimens included thalidomide and bortezomib. Median duration of exposure to ixazomib was 12 months.

Results: One patient with multiple cytogenetic aberrations and extramedullary plasmocytoma died because of progression after two months of treatment. In the remaining patients, the objective response to treatment was reached, and in four cases it was qualified as a very good partial response (VGPR). Observed adverse effects included neutropenia, infections, and oedema (in three cases Grade 3). Eight patients continue treatment, in two cases the decision was made to reduce lenalidomide doses.

Conclusions: Preliminary results suggest potentially high efficacy and good safety profile of IRd therapy in patients with RRMM and unfavourable cytogenetics.