Evolutionary dynamics of two related malignant plasma cell lines

Exploiting endogenous and therapy-induced apoptotic vulnerabilities in immunoglobulin light chain amyloidosis with BH3 mimetics

Immunoglobulin light chain (AL) amyloidosis is an incurable hematologic disorder typically characterized by the production of amyloidogenic light chains by clonal plasma cells. These light chains misfold and aggregate in healthy tissues as amyloid fibrils, leading to life-threatening multi-organ dysfunction. Here we show that the clonal plasma cells in AL amyloidosis are highly primed to undergo apoptosis and dependent on pro-survival proteins MCL-1 and BCL-2. Notably, this MCL-1 dependency is indirectly targeted by the proteasome inhibitor bortezomib, currently the standard of care for this disease and the related plasma cell disorder multiple myeloma, due to upregulation of pro-apoptotic Noxa and its inhibitory binding to MCL-1. BCL-2 inhibitors sensitize clonal plasma cells to multiple front-line therapies including bortezomib, dexamethasone and lenalidomide. Strikingly, in mice bearing AL amyloidosis cell line xenografts, single agent treatment with the BCL-2 inhibitor ABT-199 (venetoclax) produces deeper remissions than bortezomib and triples median survival. Mass spectrometry-based proteomic analysis reveals rewiring of signaling pathways regulating apoptosis, proliferation and mitochondrial metabolism between isogenic AL amyloidosis and multiple myeloma cells that divergently alter their sensitivity to therapies. These findings provide a roadmap for the use of BH3 mimetics to exploit endogenous and induced apoptotic vulnerabilities in AL amyloidosis.

Recent advances in the management of multiple myeloma: clinical impact based on resource-stratification. Consensus statement of the Asian Myeloma Network at the 16th international myeloma workshop

Predicated on our improved understanding of the disease biology, we have seen remarkable advances in the management of multiple myeloma over the past few years. Recently approved drugs have radically transformed the treatment paradigm and improved survivals of myeloma patients. The progress has necessitated revision of the diagnostic criteria, risk-stratification and response definition. The huge disparities in economy, healthcare infrastructure and access to novel drugs among different Asian countries will hinder the delivery of optimum myeloma care to patients managed in resource-constrained environments. In the light of the tremendous recent changes and evolution in myeloma management, it is timely that the resource-stratified guidelines from the Asian Myeloma Network be revised to provide updated recommendations for Asia physicians practicing under various healthcare reimbursement systems. This review will highlight the most recent advances and our recommendations on how they could be integrated in both resource-abundant and resource-constrained facilities.

Therapy for Relapsed Multiple Myeloma: Guidelines From the Mayo Stratification for Myeloma and Risk-Adapted Therapy

Life expectancy in patients with multiple myeloma is increasing because of the availability of an increasing number of novel agents with various mechanisms of action against the disease. However, the disease remains incurable in most patients because of the emergence of resistant clones, leading to repeated relapses of the disease. In 2015, 5 novel agents were approved for therapy for relapsed multiple myeloma. This surfeit of novel agents renders management of relapsed multiple myeloma more complex because of the occurrence of multiple relapses, the risk of cumulative and emergent toxicity from previous therapies, as well as evolution of the disease during therapy. A group of physicians at Mayo Clinic with expertise in the care of patients with multiple myeloma regularly evaluates the evolving literature on the biology and therapy for multiple myeloma and issues guidelines on the optimal care of patients with this disease. In this article, the latest recommendations on the diagnostic evaluation of relapsed multiple myeloma and decision trees on how to treat patients at various stages of their relapse (off study) are provided together with the evidence to support them.