A phase 2 study of carfilzomib, cyclophosphamide and dexamethasone as frontline treatment for transplant-eligible MM with high-risk features (SGH-MM1)

Response-Adapted Therapy for Newly Diagnosed Multiple Myeloma

PURPOSE OF REVIEW

The development of potent novel agents has improved outcomes for patients with multiple myeloma (MM). Heterogeneity of response to therapy, an expanding arsenal of treatment options, and cost are however major challenges for physicians making treatment decisions. Response-adapted therapy is hence an attractive strategy for sequencing of therapy in MM. Despite its successful application in other haematologic malignancies, response-adapted therapy is yet to become a standard of care for MM. We provide our perspective on response-adapted therapeutic strategies evaluated thus far and how they may be implemented and improved on in treatment algorithms of the future.

RECENT FINDINGS

While older studies suggested that early response based on International Myeloma Working Group response criteria could impact long-term outcomes, recent data have contradicted these findings. The advent of minimal residual disease (MRD) as a powerful prognostic factor in MM has raised the promise of MRD-adapted treatment strategies. The development of more sensitive techniques for paraprotein quantification as well as imaging modalities to detect extramedullary disease is likely to change response assessment in MM. These techniques combined with MRD assessment may provide sensitive and holistic response assessments which could be evaluated in clinical trials. Response-adapted treatment algorithms have the potential to allow an individualised treatment strategy, maximising efficacy, while minimising toxicities and cost. Standardisation of MRD methodology, incorporation of imaging into response assessment, and the optimal management of MRD positive patients are key questions to be addressed in future trials.

Current approaches to management of newly diagnosed multiple myeloma

Major developments in the treatment of multiple myeloma (MM) over the past decade have led to a continued improvement in survival. Significant progress has been made with deeper and longer remissions seen with newer treatment approaches-both for induction as well as maintenance therapy. The treatment approach to MM is guided by several factors including patient age, frailty, comorbidities, eligibility for autologous stem cell transplantation (ASCT), and risk stratification into standard-risk or high-risk MM. High-risk MM is defined by the presence of t(4;14), t(14;16), t(14;20), del (17p), TP53 mutation, or gain (1q). Transplant eligible patients should receive 4-6 cycles of induction followed by stem cell collection. Patients can then undergo ASCT, or continue induction therapy and shift to maintenance, delaying ASCT till first relapse. Transplant ineligible patients should receive induction therapy followed by maintenance. For induction therapy prior to ASCT, a proteasome inhibitor-IMiD combination remains standard with monoclonal antibody-based quadruplets preferred in high-risk patients. Among transplant ineligible patients, those with standard-risk MM should receive DRd continued until disease progression, while bortezomib containing regimens (VRd or VRd lite) can be considered for high-risk patients. Finally, standard-risk patients should receive lenalidomide maintenance after induction/ASCT, while proteasome inhibitor-IMiD combinations should be used for high-risk patients.