Assessment of prolonged proteasome inhibition through ixazomib‐based oral regimen on newly diagnosed and first‐relapsed multiple myeloma: A real‐world Chinese cohort study

AbstractObjectiveTo evaluate the effectiveness, safety, and convenience of in‐class transition (iCT) from intravenous bortezomib‐based induction to ixazomib‐based oral regimens.MethodsThis retrospective real‐world study was conducted in 16 Chinese hospitals between October 2017 and April 2023 and analyzed newly diagnosed (NDMM) and first‐line relapsed multiple myeloma (FRMM) patients who attained at least a partial response from bortezomib‐based induction therapy, followed by an ixazomib‐based oral regimen for 2 year or until disease progression or intolerable toxicity.ResultsThe study enrolled 199 patients, median age: 63 years old, male 55.4%, 53% as high risk (HR), and 47% as standard risk. Cytogenetic risk stratification by metaphase fluorescence in situ hybridization (M‐FISH), based on the Mayo Clinic risk stratification system. The median duration of total PI therapy was 11 months, with ixazomib‐based treatment spanning 6 months. At the 20‐month median follow‐up, 53% of patients remained on therapy. The 24‐month PFS rate was 84.3% from the initiation of bortezomib‐based induction and 83.4% from the start of ixazomib‐based treatment.Overall response rate (ORR) was 100% post‐bortezomib induction and 90% following 6 cycles of the ixazomib‐based regimen. Based on the Sankey diagrams, 89.51% of patients maintained or improved their disease response after 2 cycles of iCT, 6 cycles (90.14%), and 12 cycles (80%). The HR level of Mayo was found to be a significant independent factor in a worse remission (hazard ratio (HR) 2.55; p = 0.033).Ixazomib's safety profile aligned with previous clinical trial data, with 49% of patients experiencing at least one AE of any grade. The most common AEs included peripheral neuropathy, nausea and vomiting, diarrhea, thrombocytopenia, and granulocytopenia.ConclusionIn the real‐world Chinese MM population, NDMM and FRMM patients responded favorably to PI‐based continuous therapy, demonstrating substantial response rates. The ixazomib‐based iCT allows for sustained PI‐based treatment, offering promising efficacy and tolerable AEs.