Sequencing of nontransplant treatments in multiple myeloma patients with active disease

Induction Therapy Strategies in the Transplant-Ineligible Population

ABSTRACT

Multiple myeloma (MM), a plasma cell malignancy, accounts for ~10% of hematologic malignancies and predominantly affects the older population. It exhibits a heterogeneous biology and a complex genetic phenotype that affect patient prognosis. The treatment of MM has evolved significantly over the last decade with the use of autologous stem cell transplantation and several novel agents. Consequently, outcomes have improved in this time period, with the most impact in younger patients. Management of MM in elderly frail patients requires a thoughtful approach as majority of these patients carry multiple comorbidities and are precluded from high-dose chemotherapy and autologous stem cell transplantation-accounting for the more modest improvement in outcomes. Assessing transplant eligibility and performance status is a critical first step. Subsequently, the choice of frontline therapy in transplant-ineligible frail patients must balance efficacy with adverse effects to optimize quality of life. Here, we review the current state of induction regimens in this patient population.

Daratumumab plus bortezomib and dexamethasone versus bortezomib and dexamethasone in relapsed or refractory multiple myeloma: updated analysis of CASTOR

Daratumumab, a CD38 human monoclonal antibody, demonstrated significant clinical activity in combination with bortezomib and dexamethasone versus bortezomib and dexamethasone alone in the primary analysis of CASTOR, a phase 3 study in relapsed and/or refractory multiple myeloma. A post hoc analysis based on treatment history and longer follow up is presented. After 19.4 (range: 0–27.7) months of median follow up, daratumumab plus bortezomib and dexamethasone prolonged progression-free survival (median: 16.7 versus 7.1 months; hazard ratio, 0.31; 95% confidence interval, 0.24-0.39; P<0.0001) and improved the overall response rate (83.8% versus 63.2%; P<0.0001) compared with bortezomib and dexamethasone alone. The progression-free survival benefit of daratumumab plus bortezomib and dexamethasone was most apparent in patients with 1 prior line of therapy (median: not reached versus 7.9 months; hazard ratio, 0.19; 95% confidence interval, 0.12-0.29; P<0.0001). Daratumumab plus bortezomib and dexamethasone was also superior to bortezomib and dexamethasone alone in subgroups based on prior treatment exposure (bortezomib, thalidomide, or lenalidomide), lenalidomide-refractory status, time since last therapy (≤12, >12, ≤6, or >6 months), or cytogenetic risk. Minimal residual disease–negative rates were >2.5-fold higher with daratumumab across subgroups. The safety profile of daratumumab plus bortezomib and dexamethasone remained consistent with longer follow up. Daratumumab plus bortezomib and dexamethasone demonstrated significant clinical activity across clinically relevant subgroups and provided the greatest benefit to patients treated at first relapse. Trial registration: clinicaltrials.gov identifier: 02136134.

Myeloma and Bone Disease

PURPOSE OF REVIEW

Bone disease is a defining characteristic of multiple myeloma (MM) and the major cause of morbidity. It manifests as lytic lesions or osteopenia and is often associated with severe pain, pathological fracture, spinal cord compression, vertebral collapse, and hypercalcemia. Here, we have reviewed recent data on understanding its biology and treatment.

RECENT FINDINGS

The imbalance between bone regeneration and bone resorption underlies the pathogenesis of osteolytic bone disease. Increased osteoclast proliferation and activity accompanied by inhibition of bone-forming osteoblasts leads to progressive bone loss and lytic lesions. Although tremendous progress has been made, MM remains an incurable disease. Novel agents targeting bone disease are under investigation with the goal of not only preventing bone loss and improving bone quality but also harnessing MM tumor growth. Current data illustrate that the interactions between MM cells and the tumor-bone microenvironment contribute to the bone disease and continued MM progression. A better understanding of this microenvironment is critical for novel therapeutic treatments of both MM and associated bone disease.