Clinical value of molecular subtyping multiple myeloma using gene expression profiling

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Multiple myeloma (MM) treatment response varies significantly across patient subgroups.
• Identifying distinct molecular and risk profiles is essential for personalized therapy.

Purpose of the Study:

• To evaluate the impact of novel therapies on molecular and risk subgroups in multiple myeloma.
• To assess the clinical utility of molecular classification in predicting treatment outcomes.

Main Methods:

• Analysis of a dataset of 1217 multiple myeloma patients from Total Therapies trials.
• Examination of treatment effects (bortezomib, thalidomide) on progression-free survival (PFS) and overall survival (OS) across molecular subgroups (MMSET, MAF/MAFB, t(11;14)-containing) and risk groups (low-risk/LoR, high-risk/HiR) defined by GEP70 signature.

Main Results:

• Bortezomib significantly improved PFS and OS in the MMSET subgroup.
• Thalidomide and bortezomib enhanced PFS in low-risk (LoR) cases but not high-risk (HiR) cases.
• t(11;14)-containing subgroups (CD-1, CD-2) showed differential response times but similar PFS/OS.
• Complete remission did not significantly correlate with outcomes in MAF/MAFB (MF) or HiR subgroups.
• High-risk cases were enriched in MF, MMSET, and proliferation subgroups, with poor outcomes not solely attributed to MAF overexpression.

Conclusions:

• Molecular classification is vital for predicting multiple myeloma outcomes based on response rates.
• High-risk (HiR) multiple myeloma patients require tailored management due to aggressive disease and early relapse potential.
• Defining risk status is critical for optimizing therapy and maintaining pressure on the myeloma clone in HiR cases.